Saturday, April 21, 2012

Polarity Testing the Oppo BDP-95

Above is the output of my Oppo BDP-95 player playing my SoftPolarityTest CD track one, through single ended stereo outputs, as viewed on a Tektronix scope.

A friend has been asking me to test the output polarity of the Oppo BDP-95.  Long ago I made a polarity test by recording a B&K analog function generator.  I started with a square wave at 400Hz and decreased the duty cycle so I had only a positive series of pulses at 400Hz.  I originally recorded this at a fairly high level, so it was dangerous to use.  Well this time I altered that by reducing the level 18dB.  I recorded the disc onto a T.Y. CD-R using a MacBook Pro.  I call this SoftPolarityTest.  You perform the test by playing the recording and watching the results on an oscilloscope.  If the visible pulses go positive, this is correct polarity, or at least it is correct compared with my reference standard for polarity, a Sony 507ESD high end CD player made in the 1980's and all other CD players I have tested so far.

Each track lasts 20 minutes so there is little chance of error.  I skipped ahead to the second track, which is the same recording in reverse polarity:

Here is the Sony 507ESD with the disc inserted.

It took about 11 minutes to get the scope hooked up to the sony because it is at the bottom of a pile of equipment in a tight space.  Here is what track one (I double checked) looks like on the Sony:

Here is the Denon 5900 playing track one:

So all three players have the same output polarity.  If I remember correctly, I previously tested a Samsung DVD player and a Toshiba 5700 (a model not made by Samsung like later Toshiba's were) and they had the same polarity also.  These are the only disc players I have ever tested for polarity, and none have been different.  I believe that is because all the ones I have tested are correct.

Thursday, April 19, 2012

Funky smell

From my first use, I've noticed a smell coming from the Marantz 2130 that I associate with deteriorating electrolytic capacitors.  I've smelled this smell mostly on older equipment that needs to be refurbished.  Though I was also wondering if a previous owner of this unit was a tobacco smoker.

Before installing the tuner, I washed off outer case and bare chassis areas.  The smell was still quite noticeable an annoying to me in the kitchen.  A lady friend did not smell it.

I put my hand on the top case of the Marantz, and my hand picked up the smell.  OK, so now it occurred to me it was mostly coming from the funky vinyl coating on the top cover.

I removed the cover again, leaving the tuner uncovered in it's rack spot, pushed back so I don't accidentally try to put my hand on top again.  Some say equipment sounds best with it's cover of, and it did seem a bit that way, I noticed more depth and spaciousness.  Despite the vinyl coating, the Marantz top cover vibrates when music is being played through the speakers.  That can't be good for a tuner using ceramic and SAW filters which operate through mechanical sound transmission.

I rubbed the cover off again several times with Everclear, then put outside for sun exposure during next day or so.  I've been thinking the bad smell is from oxidation, and perhaps coating the vinyl with Deoxit would help.

I'm thinking I could make a different cover out of some damping material.  Possibly a single flat plate for the top of the tuner would be sufficient, leaving sides open, but possibly with some extra protection for the front.  I don't like putting wood cases on equipment like this because it already runs quite warm and I think that would make it run too warm for long term.

Tuesday, April 17, 2012

More Marantz 2130 pictures

Well, as I expected, the underside of the Marantz 2130 is covered with circuit boards.  Combined with the RF and IF circuitry on top, there is quite a lot of stuff in this tuner.  I started examining underneath the tuner on Saturday night.

The power supply in middle center looks about as big as in a Kenwood 600T, however it should be noted this one here also supplies power for the scope.  There are some nice looking large Nippon Chem Con capacitors in that power supply, and nothing looks underrated, no sign of cooking (as with the undersized resistor in the Sansui 9900).  The MPX board is on the middle right. The board in left front is the buffer board which includes features such as high blend and the oscillator.  Somewhere the quartz lock board is tucked in.

Above is a closeup of the MPX board.  In there is a Hitachi HA11223 mpx chip with external switching transistors.  The big modules on left are 38Khz subcarrier filters...those need to filter down to 22Khz.  The MPX board uses a pilot canceler implemented with discrete circuitry to remove the 19Khz pilot from the output.

Above is a closeup of the power supply board.  There are 3 heatsinked semiconductors on the right, and one in a larger heatsink on the left.  In addition to the fuses on this board, there is a fuse on the case.

Above is a closeup of the buffer board.  Both the mpx and the buffer feature single 4558 output IC's and relatively large electrolytic capacitors.  I worried a lot about the black dot on the large capacitor near the center of the photo.  I wondered if it had been painted on and in fact it's hard to tell as there is no other sign of leakage than the back mark and a slight depression where it is.  If it was caused by having a leak once, it appears to be completely sealed now.  It turns out to be a capacitor in the oscillator circuit, so I'm not too concerned about it.  However, the entire tuner did have what I often consider the "bad capacitor" smell.  I doubt that it all came from the one above, but it might have.  I washed and dried the entire exterior case over the weekend, allowing each piece ample time to completely dry.  I wiped bare chassis metal, and transformers, and accessible parts of the scope.  Everywhere I wiped in picked up some brown, perhaps some previous owner was a smoker though it doesn't small like smoke as such, it smells like bad capacitors.  All the cleaning reduced but did not eliminate the smell.

At first, I had some trouble getting the bottom cover back on.  It's held in place with screws around the perimeter, and only goes on one way, but one of the screws, toward the backright corner near the RF connections, is extra long, and apparently intended to make contact with the metal of the RF shield.  It has to be jammed in just so or the cover cannot be screwed on as it bulges near that corner.  The bottom cover itself is rather thin metal to be supporting such a heavy unit--or even a light unit.  It flexes easily.  This appears to be another design feature.  When the unit is put down, the bottom metal panel flexes enough so that unless your surface is very uneven, all 4 hard plastic feet will touch the surface underneath them.  But don't pile too much equipment on top!  When I push down on the top of the tuner, I can feel the metal plate underneath giving slightly.  This could also be a cultish audio feature in the sense that the bottom metal panel is undamped and therefore "live".

I washed the bottom panel first, then let it dry overnight because I was going to bed anyway.  The next day I put the bottom back on, and then took the top off for washing.  At that point, I noticed a serious fault in the tuner.  The wire going to the tuner position indicator light is sagging down onto the IF board.  As you tune from low to high and then back down again, it catches on various parts on the circuit board, including the very critical and valuable SAW filters.  Over time, this could cause misalignment or serious and possibly unrepairable damage to the IF board, which is the very heart of this fine tuner and the key to its above average performance.

I was unable to find in the manual how this is supposed to be done.  Perhaps the wire originally was stiff enough that it didn's sag in the middle, or perhaps (and most likely) the wire was surrounded by a piece of heat shrink either from the dial side or the other side (the wire was originally attached to a wire clip on the cover of the RF unit).

Heat shrink might be the best solution, but it would require at minimum unsoldering the lamp without damagin the plastic, a very tricky operation.  That might have been why Marantz Service didn't fix this.  Perhaps the original heat shrink got damaged and was jamming the dial, so they just removed it, and didn't bother to replace, not realizing that the above problem could occur.

I came up with a fix that did not require any soldering.  I cut a nylon wire tie and placed it across the valley of the inside of the tuner from RF cover, where the now unused clip for the lamp wire is, over to the dial, where it is jammed between the circuit board and the dial plastic.  As the indicator moves across the dial, the wire tie supports it in the center about an inch from the circuit board at worst case (shown in picture).  Most of the time, it is much higher than this.  It took about an hour of tweaking to get it this good.  I still worry about a number of things, including the possibility that over time the vinyl covering on the lamp wire will wear off rubbing against the nylon tie.  But I suspect that won't happen fast, if at all, and hopefully just disable the lamp or blow a fuse.

Followup to Marantz 2130 review

I posted this followup to my early review of Marantz 2130:

Thanks! By some stroke of good luck, my favorite station KPAC turned on full
power Saturday, first time in 6 months, just in time for some tuner rolling all

Contenders: Pioneer F-26, Marantz 2130, McIntosh MR78

F-26: Most transparent, most 3D imaging, neutral tone with slightly soft highs

Marantz 2130: Most pleasant, best at rejecting interference in widest wide,
quietest sounding, most musical and dynamic, slight midbass emphasis, softness
in mid highs but open in extreme highs.

MR78: Very clear sounding, uncolored, squeaky clean, but easily perturbed by
interference in wide causing grating sounds--same as with slight off-tuning.
Super narrow is a pin point.

MR78 had Modafferi Mod and alignment in 2001; F-26 rebuilt by ASL in 2011: 2130
aligned by Marantz authorized service in 2012. It still bugs me that wnen
Modafferi modded what was to become my MR78 he bragged (in the documentation)
about getting the adjacent selectivity up in wide mode...just the opposite of
what the tuner needs IMO.

I'm more and more impressed by the 2130. I think this is just below the top
tier of tuners like TU-X1 (by reputation and info, not tested by me) and better
than many acclaimed supertuners like Kenwood KT-8300 that I have some experience

Though it only has 5 gang air capacitor, the specs, even the RF specs, beat
KT-8300. I'm not sure if that's really true, but it does work better for me
primarily because of better quieting curve. RF specs are as good as L-02T and
audio specs fall just shy of L-02T mainly in separation, where the Marantz still
does an impressive 55dB at 1Khz and 50dB across the audio band. Stereo THD is
at 0.07%.

One thing that I think may be very special about the 2130 is how wide the wide
IF is, and maybe something about how it's tuned at the cutoff points, and
likewise the detector, in ways that are similar to 20B, which has similar sound
but much less sensitivity.

The 2130 wide is so wide that when you tune from one station to another 400Khz
away, with muting and lock disabled, it nevertheless snaps from one station to
the other with relatively small patch of noise in between. Slight off-tuning
has almost no effect, in fact you can be tuned more than 100Khz off and there's
still no splatter (though you've lost Stereo). Capture Ratio is specified as
0.8dB. I think this is why the Marantz shrugs off inteference better than the
others and always sounds dynamic, musical, and pleasant.

The narrow is nicely narrow, like other good tuners, but might be even more cool
if it were as narrow as MR78 super narrow. You can see images corresponding to
very weak stations on the scope, and that helps tune them in, but the lack of
ultimate selectivity keeps it from matching the MR78 in picking them up. The
Modafferi modded MR78 might also have more ultimate sensitivity even if not as
steep quieting. I'm now thinking a filter mod for the Marantz narrow might
indeed be a very good idea. But I don't want any changes to the wide IF.

For now, I'm keeping the transparent and 3D Pioneer in my living room for my
electrostatic speakers, but the Marantz is just the ticket for my Kitchen radio
shack which plays on good dynamic speakers. The MR78 goes back into the pile.
I've rarely had so much fun listening to FM.

Early Review of Marantz 2130

I posted this review to FMTuners on Monday April 16:

I like the sound of the Marantz 2130, it performs well, has almost every feature
found on FM tuners including, of course, a scope. The scope was why I bought
this tuner, after thinking that the scope on the 20B was too small to show
anything interesting about my favorite station KPAC. Actually, my 20B badly
needs a whole refurb, it makes occasional popping sounds, and the scope display
just has shrunken smaller than it should be, even with the small scope onboard.

This is a relatively accurate sounding tuner, and in that sense unlike the 20B
which I consider more of a musical instrument which somehow enhances
tunefulness. The 2130 is quiet and sensitive, quieting seems to be in same
ballpark as Pioneer F-26, still my reference tuner. The Marantz is easier to
play with, however, if you are exploring the dial, because all the controls,
including variable muting and variable output, IF bandwidth, high blend, mono,
and the quartz lock switch are on the front panel. I've long suggested I wanted
onboard attenuator rather than muting and here it is. I suggest using the
onboard volume control as a temporary attenuator while tuning, then turn it back
to 100% when fully tuned. It should not be used as system volume control
because it does not have perfect tracking between channels and there is
considerable image shift at the bottom end, just like almost all potentiometers.
Also, the quartz lock should be kept defeated as it tends to pull stations
slightly off center, even on my freshly authorized service center aligned unit.

About the sound, it's definitely on the warm side, but sounds open in the highs
as well. I'm wondering if there's small boost in the midbass and upper highs
above 6Khz. But it sounds very pleasant and not overdone and musically
enhancing, if indeed there are any frequency response tricks at all. I
generally think Kenwood tuners have a slightly brightish sound, I often think
this is honest accuracy, but it's not always appealing. Pioneer tuners seem to
get the balance right on, better midrange. The Marantz steps one step more away
from the classic bright Kenwood sound as typlified by KT-7500, but still has an
open sound, not sounding rolled off at all.

I greatly preferred the sound of 2130 to 600T. The 600T sounded coarse, grainy,
and dry compared with the Marantz. I confess my 600T has never been aligned and
possibly needs some alignment, even though the Pulse Count detector may need
less frequent alignment than any other design, and my 2130 was just aligned by
Marantz service center. OTOH, my 600T has been refurbed, and the Marantz
hasn't. But I have also been coming more and more to agree with those like
Anonymous Dave who say that old Kenwood Pulse Count detectors just don't get it
right. IMO, they weren't using a high enough 2nd IF frequency, and for that and
other reasons there is just too much information loss with that kind of system.
Less noise, less need for alignment, but less information too.

Overpriced? I've been shocked by the relatively low recent sale prices of such
all time greats as TU-X1 and L-02T, while it seems that people selling Marantz
tuners, especially 20B and other scope units, have been climbing higher almost
to reach them, and I think that's insane. But I like the sound of 2130 much
better than 600T, I believe they sold for about the same price in 1978, and the
Marantz has a scope. What's a scope worth? Well you can get nice used
professional scopes relatively inexpensively, but it's not easy to keep one of
those integrated with a hifi system. They're generally too big, and they always
find different uses right away. A dedicated scope would be nice. Nowadays
those go for high prices too. I just lost a bid on a Kenwood KC-6060A scope
which sold for $750. Mac MPI3's are listed for about $1000. BTW, I'm thinking
now that a scope could not be replaced by LCD display. It' has to be super fast
reacting, and show microscopic fuzz lines, to be useful.

Even if you have one of those nice hifi scopes, it takes one more equipment
space. I'm running out of equipment space in all my systems. Having the scope
integerated into the tuner, even if it's only a small scope, is nice. That way
it's always there, and it doesn't take more space. It makes for a very
reflexive tuning experience, you can see each station go by as you're spinning
the dial on the "multipath" display. Plus there's the very interesting L/R
display, which can expose some of the tricks being pulled as well as how much
separation you are getting. Plus, it's fun, lots of fun, and I think that's
important too.

I've heard these things can get filter mods and become top DX'ing machines after
that. I'm not really sure how much this tuner is limited by the lack of
narrowness in the "narrow" position, it's already pretty selective. Somehow I
doubt this has the kind of bulletproof or pristine front-end that the tuners
more praised here do, and that may be more of a limitation for ultimate dx'ing.
It *seems* plenty sensitive too, but there are most likely much quieter front
ends. OTOH, I think the air capacitor sets this above most varactor-based
tuners right there in most cases. FWIW, Marantz claims 110dB IMRR vs only 85
for my forthcoming L-1000T, I'm beginning to think that is a key spec for
musicality, keeping RF grundge out of the audio, so maybe this is more of a
sound quality spec even though it typically appears in the RF section specs.

Thoughts about modern vs vintage tuners

I posted this to FMTuners:

Substitute "Kenwood L-02T" or "Sansui TU-X1" for 10B, then you have interesting

Answer: Accuphase continues to march on making superb tuners for analog FM
broadcasting, other old names have either thrown in the towel altogether or
aren't spending enough money on it anymore. There is little chance that the
circumstances that led to the great tuner race of the late 1970's to early
1980's will occur again. There are a few recent fairly serious tuner makers now
like Magnum Dynalab, and a whole cottage industry of tuner restorers, modifiers,
and tweakers. And there is a huge glut of old units that have been cast off,
just waiting to be modified, restored, etc. And most of them can be made to
sound as good or better than 10B

HD digital subcarrier broadcasting squeezes your actual bandwidth/bitrate down
to practically nothing. The information in a full analog broadcast is
potentially greater than CD. It relies on psychoacoustic masking like most
lossy compression systems. Such masking isn't perfect, the ill effects can
easily be heard. But those who just want low noise can be fooled.

I've never hard a 10B, but my current opinion is that the 20B was Dick
Sequerra's best tuner because it gets key details right. A single RF amp, air
capacitor tuning, and very wideband IF and detector. This SS tuner dates from
mid 1960's early SS but is still a classic that other designers should know
about. OTOH, 10B uses two RF amps and is prone to IM, in fact the IM is always
there, has a relatively narrow "compromise" IF, and a vestigal MPX decoder that
throws away half of the stereo subcarrier to reduce noise, not a good place to
start IMO. But there are a limited number of 10B's, it has a legend and a cult,
and it's cool looking and I've bid on them too.

There is a lot of potential wrt digital RF sampling and processing, but other
than Accuphase, nobody is pushing the technological envelope for receiving
analog broadcasts in greater true fidelity. Digital Tuners are generally made
for car radios and generally focus on eliminating noise through dynamic noise
suppression and other trickery that doesn't make for the highest fidelity. In
general, there is no substitute for linearity and wide bandwidth, but someone is
always trying to sell one.

Thoughts about Day-Sequerra and other tuners

I sent this email also:

The D-S "FM Reference" isn't any fun, IMO, without the Panalyzer.  Few models had that because it doubled the price.  I'm not sure that one does.  It is said to be a very good performing tuner.  There are so many different sequerra models over the years I'd like to hear some for myself.  The Reference got very good reviews in Stereophile, fwiw, better than what Accuphase had in 1992 they said.  It uses better BB audio chips than japanese tuners (other than recent accuphase) and has balanced output.

Nowadays D-S makes professional broadcast monitors, and their specialty seems to be monitoring HD radio with all possible options.

The original Sequerra Model One only came with the Panalyzer.  There's been one of those listed on eBay for $5000 obo for several weeks now.

It's a steep price to pay for by-many-accounts-lousy tuner with spectrum analyzer.  I got boat anchor HP unit designed for certifying cell phones that has spectrum analyzer that works reasonably well in 100Mhz band, I can get FM spectrum displays that look similar to Sequerra.  That cost me $400, but far too inconvenient to use mostly.  Now I was thinking, if I could have some gizmo that sampled the LO on my Marantz, sent the info to the HP serial port,  HP generates appropriate display, then sends it back out to marantz scope.  Actually, though, the HP has NTSC video output, not X-Y, and the unit has very annoying lag and menued controls.

I think 10B had 4" scope, the 20B has 2" scope, and the 2130 has 3" scope.  The scoped sequerras have have 5" scopes, the nicest of all.

Nice interface.  What they needed was user replaceable module for the actual tuner.

I'm now of the opinion that 10B wasn't Marantz best tuner.  20B and 2130 were.  The 20B especially exemplifies the correct classic design principles: single RF amplifier, extremely wideband IF and detector.  By all accounts, the 10B has relatively narrow "compromise" IF, they bragged about (hypothetical) 150dB selectivity, and dual RF amplifiers that are very sensitive but infamously prone to IM, and quasi-vestigal MPX which throws away half of the stereo infomation.  I think the 2130 tames its two RF stages by virtue of well tuned AGC with dual gate Mosfets.

Dick Sequerra was on to something with the mostly underappreciated 20B.  But the virtue of wide bandedness was lost in the noise of selectivity spec wars of the 1970's.  His second tuner was better than the first.  But reaching for the gold ring, with the Sequerra Model One, he reached prematurely to make a great tuner with varactors, which didn't work.

Tuner Rolling Weekend

I had great fun rolling tuners on the weekend of April 15th.   Ended up with 2130 installed in Kitchen, as planned, and loving it.  Here's one email to a friend on Monday:

 I had a wonderful weekend playing with 3 tuners, F-26, Marantz 2130, and MR 78.

I like what the Marantz does, it's very sweet and is better than any tuner at rejecting bad sounds in its wide mode which is, just like the 20B, very wide.  It just as quiet or quieter than Pioneer under real reception conditions.  I strongly believe it's quieter than KT-8300 especially in the mid range of signal strength from 30-60dBf, though this is from memory.  It's narrow is quite narrow, but the MR78 still has narrower super narrow, which might be nice for that function.  The Pioneer is ultimately more transparent and 3D and more neutral frequency balance.  But my F-26 is playing with hands tied behind it's back.  The auto function refuses to go into wide on KPAC or any of the stations I listen to.  I wonder if it is making this choice correctly.  The 2130 sounds best it its wide mode on these channels with no apparent interference.  I think I want to defeat the Pioneer auto-narrow somehow, then the F-26 could be EVEN BETTER.  IMO, the F-26 would work fine for me as a wide-only tuner, like the Marantz 20B.  Then, when I want to do DX'ing, I can use the narrow on the Marantz 2130, which I could get in narrow mode only (it has separate IF's).  I don't need to do DX'ing on my living room system.  The Marantz has earned it's place in my Kitchen system, based on Revel M20 speakers, for reflexively spinning the dial, always sounding good, and DX'ing, and is better for that than I had imagined.  The more transparent Pioneer stays in the living room where its virtues can be appreciated.

The MR78 has that cool needle-like super-narrow (which actually uses a crystal filter imperfectly, it's not Modafferi's RIMO filters doing that) and, in it's "wide" (compromise) mode sounds clear, very clear, when everything is quiet.  But the least bit of multipath or something sets it off with a kind of crinkling sound, which sounds especially bad on the MR78.  The Pioneer actually has the same problem.  The Marantz just rejects that noise, whatever it is.

My current theory: the crinkling sound is loss of capture.  The super-wide everything on the Marantz gets the capture ratio down to 0.8, and it really holds on.  And possibly some other way they handled the IF, makes it capture beautifully.  Imagine tuning from 88.3 to 88.7 with nothing much in between.  As you get to around 88.4 the marantz is still sounding undistorted, no crackling sounds, though stereo carrier is lost (by that time, the MR78 in wide has lost the signal in a downpour of aggressive noise).  You don't start getting crackling sounds until you are approaching 88.5.  Then, they don't last long, the capture effect quickly captures 88.7.  This is not AFC (or at least I don't think it is, you get something like AFC with the quartz lock, and that is best left off), it's the result of wide band IF with good capture ratio.

FWIW the 2130 specs, even the RF specs, are better than 8300.  It's RF specs are the equal of the L-02T.  I'm not sure if I believe that.  But it is good, at least as good as 8300 in RF, it seems to me so far, and way better overall.  The front end must be better than it looks, and the IF may be better here than just about anywhere else.  I think it's probably the IF that is the main magic in the 2130.  The MPX is similar to Kenwood's late 1970's models, HA11223 chip with external transistor switching, and pilot canceller like 917.  Nothing obviously special otherwise.  FWIW Marantz claims very flat frequency response, so you might think they don't get their nice midbass warmth by frequency boost.  I think the power supply, which does use large and nice looking caps, may not be as tightly regulated, another thing I want to look at. The case which has slightly damped top panels is completely undamped at the bottom.  In fact, the bottom is just a thin sheet of sheet metal secured around the perimeter with screws.  When you set it down, the thin sheet metal "gives" just enough so that all 4 feet are making contact.  That seems a bit tweaky but it works in at least one way. 

I think models using LA3450 get pilot cancelling for free.

Also heard great rendition of Vivaldi with a marvelous soprano at the Symphony on Saturday Night.  I felt it was magical how she could play the room.

Sunday, April 15, 2012

Marantz 2130 Specs

I wasn't sure if I could believe any online specs.  Ben Blish is a 70's marantz proseletyzer.  Lots of people may crib there numbers from him.  I thought it was very suspicious that Marantz did not include any performance specifications in the owner's manual.  Lots of technohype, no specs.

But I did find specs in the Marantz Service Manual.  I believe those are official.  And they are superb.  They are clearly better than the specs of the Kenwood TX-8300 even in the RF area.  That doesn't seem believable.  The TX-8300 uses a much larger 6 gang capacitor, and of course it has a serious reputation.  The 2130 didn't have much reputation, possibly undersevedly so, until Ben Blish or one of his predecessors started bragging about 70's Marantz.

So, do I believe the Marantz specs?  I don't know.  I think there's room for doubt.  Anyway, lets compare the specs of Marantz 2130 to Kenwood KT-8300 by their numbers:


Image Rejection
Marantz 120dB
Kenwood 110dB

IF, Spurious
Marantz 120dB
Kenwood 110dB

For all of the above RF specs, the Marantz is the equal of the L-02T !

Stereo Sep. Ikhz, wide
Marantz 55dB

Stereo Sep 100-10Khz, wide
Marantz 45dB

Frequency Response, 30-15Khz
Marantz +0.2, -1dB

THD, 1Khz, Stereo
Marantz 0.07%
Kenwood 0.1%

THD, 6Khz Stereo
Marantz 0.2%

Sensitivity, Marantz
IHF 1.5uV, 8.75dBf
50dB Mono 2.2uV, 12.1dBf
50dB Stereo 25uV, 33.2dBf
78dB Stereo 1000uV, 65dBf

Saturday, April 14, 2012

Inside the Marantz 2130

After my rather fast sonic test, I wanted to move the Marantz into it's chosen spot, replacing the MR 78 whose tone I've found less enjoyable over time.  But first, I needed to have a look at the inside.

The cover removed easily.  It is metal with some kind of vinyl coating, doesn't ring much.  It is held into place with screws and washers.  Most tuners don't give you the washers.  Marantz wants you to feel that this is an audiophile luxury tuner.  Well that's only partly true actually.

At first glance, the top circuit board did not look adequate for a supertuner.  But it's not the only board,  it's merely the IF and AM Radio board.  The AM radio being mostly handled by a chip, most of the board is for the IF stage, which is relatively the most impressive technical aspect of the tuner, and right up there at supertuner standards.  The bottom of the chassis is also covered in boards not entirely visible from the top.  So consider the entire unit having roughly two layers of circuit board across the entire width and depth.  You are getting a lot of circuit board and parts for the original factory list of $600.  But a lot is related to the gee whiz features and the scope.  With a few exceptions, the actual parts and build quality is not as good as high end supertuners such as Pioneer F-26, Kenwood 600T, and McIntosh MR 78.  The latter are like tuner jewelry compared with the Marantz, which looks a bit pedestrian in comparison.  But that's not surprising.  In 1978, an MR78 cost about 3 times as much as a 2130.  And if you add in the McIntosh MPI3 scope, it would be 4 times as much.  The Kenwood 600T is much higher build quality, especially in the RF stage, but lacks scope and in my opinion doesn't sound as good.  I think of the Kenwood 600T as a failed experiment, the L-02T is their ultimate tuner, and it has both the build quality and the sonics (according to reports, I haven't heard one myself).

One exception to the pedestrian build quality being the SAW filters, even few supertuners have those.  The IF is very nicely done, with separate narrow and wide paths.  That allows for modifying the narrow path for better selectivity, and leaving the sonically critical wide alone.  Both narrow and wide have their own SAW filters, which is why there are two.  That enables them to correct the phase linearity of both paths independently.  It looks like Marantz put more of their tuner budget into the IF stage than comparable tuners, and less into the RF.  That's similar to the Marantz 10B and 20B.  I am considering the KT-8300 to be a "comparable" tuner in technology, build, and cost, though I'm sure many would be upset by that comparison, many tuner fans would regard the KT-8300 as greatly superior, though audiophiles in general might prefer the Marantz.

And FWIW there are two transformers, with a separate one for the scope.  They are not large transformers, but they are both shielded transformers.  That's not unsual for good tuners.  The transformer for the tuner looks like the one in the Charlie.

I haven't looked at the bottom boards yet, but looking at the schematic I got from Hifi Engine, the MPX is like Kenwood KT-8300, with Hitachi 11223 MPX chip connected to two external transistors for actual switching.  The MPX board uses a 4558 for output amplification, and output through a 10uF capacitor and 3k resistor.  Then there is a separate buffer board, which buffers output either from FM or AM sections, applying volume control, filtering, etc.  It also uses a 4558 for amplification.

The least impressive looking thing is the 8 section tuning capacitor and front end section, which has 5 sections for FM and 3 for AM.  It's relatively small compared with those in the big dog supertuners.  It does have a cover, unusually open toward the front.  The Kenwood KT-8300 has 6 gangs for FM, a step up. FWIW Marantz does give you two Mosfets, the first being dual gate for a kind of automatic sensitivity control.  Many believe the best front end design uses only one RF amplifier.  Two is kind of an easy way to get high sensitivity, but at the cost of slightly higher noise and high susceptibility to distortion in the RF stage.  I can't be too critical of the Marantz on this, however, as the Pioneer F-26 also has two RF amplifier sections, and the gain control of the dual gate mosfet does help avoid overload.  And even if the 5 RF gangs are small, they are still air capacitors which generally have much better characteristics than the varactors that have been used in almost all digitally tuned tuners, which means almost all tuners made since 1980.

Unlike previous Marantz scope tuners, there is no attempt to cover every circuit module in a metal box.  But I think this tuner may have better actual circuitry, and the functions are separated into separate boards in such a way as to not need shielding as much.  I do see two interesting shields.  The gyro touch flyweel has a shield.  That's a good idea, protect the tuner from being injected with noise conducted through the body of the user!  There's also a shield protecting the scope adjustments from the scope transformer.  But in daylight, I see it is not a metal shield but a piece of plastic.  Perhaps the purpose is to keep dirt out of the scope controls.

I wouldn't say Marantz was ripping you off, quite the reverse, considering the scope and everything Marantz was probably barely breaking even on the production of this tuner, let alone its design.  The scope alone with its own circuit board and power supply looks like it would cost $200-$500 in today's prices, and that has to be considered a major piece of what this tuner is about.

Nor did Marantz "not have a clue."  With a MPX circuit similar to Kenwood KT-8300,  and other aspects of the design, it looks like these designers knew what they were doing.  They were making a nice sounding good performing tuner with a scope.  I imagine that the designers may have even had a KT-8300 on hand, with the orders from management to make something slightly better, and the Marantz indeed has many slightly better specs, and includes a pilot canceling circuit which the KT-8300 did not have, having been introduced the year earlier.   In fact, this tuner even looks a bit more like a Kenwood tuner than an older Marantz, lacking the fancy internal boxes of earlier Marantz tuners, and instead having layers of horizontal boards not unlike the Kenwood tuners of this time.    For this unit, in 1978, the tuner race was at its peak, and Marantz was struggling to not be seen as tuner laggard, lots of money were spent on parts, design, and exterior appearance, little left for internal cosmetics.  Was this tuner OEM'd to Kenwood?  And at that time the Japanese hifi companies were in their most intense competition ever, so I doubt it.  I noticed that with the exception of the dial light boards, all the other boards in the tuner do not use the old Standard Radio phenolic that was in my 2270 receiver.  They use a newer lighter material, which looks a lot what Pioneer used in tuners like the TX-9500, though not the even more advanced yellow material Pioneer used in my F-26.

You have every right to question, however, whether you want about 1/3 of your tuner budget to go into the scope, which is really more fun than essential.  And even into the relatively nice cosmetics, though they may actually be trailing in this price class.  This is not anywhere near as glamorous as a Kenwood 600T.  Once again, the money went into the scope, though money was spent on the somewhat gimmicky panel.  It's gimmicky looking, I think, like a 1970's cadillac, but the front panel is actually slightly thicker than necessary and nicely satin gold anodized.  That cost a few bucks.  The display is a very nice plastic, a much nicer plastic than on early generations made by Marantz Japan.  It's almost invisible, could be mistaken for glass, and there's not much visible from a distance but it actually covers a great deal of the upper panel.  Because it's nearly invisible, you see right through to the fully finished metal.  So that was a nice refinement of what Marantz Japan had been doing with earlier tuners, which had a much cheaper looking plastic dial, though what was needed was more like leaving the past behind, as was done with the Esdotec restyling which transmuted the 2130 to the ST-8.

I dislike the gaudyness, but it's completely functional and has a nice luxury feel.  The knobs turn with oiled smoothness.  But the the knobs and buttons are still the same old plastic with metal covering.  Well maybe that's not high end, though perhaps it offers some advantage in electrical isolation.

As an earlier user of gyro touch tuning, from 1973-1979 (I started using KT-7500 in 1979), I quickly came to despise it.  It's not really as convenient as having a knob.  Humans naturally grasp things, so the best ergonomics come from things that rely on that, knobs and computer mouses.  But I can live with it.  It's less of an impediment for small movements across the dial.

  If you have specific needs that require a strong FM front end, this may not work for you, but it works fine for me, I think, we'll see.  I'm moving aside a much more expensive tuner, the MR 78.  I think the MR 78 could be a winner with the right MPX adapter.  I do have an MPX-100, but I think that's not really the best anymore.  An analog multiplier or LA3450 would be a good start.

KPAC back to stereo; Pioneer F-26 beats Marantz 2130

Early Saturday AM I came home from work and turned on the Marantz.  I then tuned it from KSYM which I had been jamming to on Saturday AM to KPAC for background music.  After a couple minutes I realized I had forgotten to engage the Mono switch.  Went back to stereo.  No hiss!  Took a look at Marantz scope.  Rather than a tiny trace below the centerline, KPAC was now visible as a full width trace well above the centerline.  KPAC is back to full power after 6 months and I can get quiet stereo again!

The Marantz sounded very quiet, pleasant, and musical on KPAC in stereo.  But it was time for the shootout with my big dog, the Pioneer F-26.

Both are very pleasant, musical, quiet, spacious, wide stereo separation.  The difference is very slight.  The Pioneer is a tad lighter sounding, less midbass, possibly a tad more high frequency noise.  I suspect the greater apparent HF noise results from a slightly less rolled off deemphasis.  The Pioneer is more transparent, 3 dimensional.

An audiophile can get very worked up by things like this, give the losing tuner a bad name.  It should be emphasized that the sonic difference here is very slight.  I sometimes thought I was listening to the Pioneer when I was listening to the Marantz.  I could be happy with either one in my main system.  Sometimes the Marantz actually sounds more pleasant than the Pioneer.  Both of these tuners have a tone that seems every so slightly soft compared with reality, and somewhat more soft than most Kenwood tuners I've heard.

But I bought Marantz for my kitchen radio shack,' a role that it is perfect for.  It's slightly more softened sound is just the ticket for my very transparent Revell M20 speakers that are almost close enough to be near field, and for exploring the FM dial with all the convenient front panel controls and scope.  The F-26 works great with my living room planar system, where I mainly just keep it tuned to KPAC, which I can listen to all over the house.

The old KPAC 10Khz buzz is gone!!!  Hurray!!!   After 15 years and complaints to the station engineer, they finally fixed it during a transmitter rebuild.  Early saturday AM, however, there was low frequency hum, especially noticable during announcements, receding but not going entirely away on music.  Well that should be obvious to more people and get fixed soon I hope.

Friday, April 13, 2012

Attention. Too much information?

The number one job of any audio component, or for that matter any personal entertainment device, or education device, or information device... is to keep your attention.  For if it hasn't kept your attention, it might as well not be there.

How anything, or anyone, keeps your attention is by emitting information.  But it has to emit the correct kind and quantity of information.  Too much information, and you will turn off.  Too little and you will be bored and loose attention (which doesn't necessarily mean leaving, it could mean you just fall asleep).  And the correct quantity relates to the kind of information it is as well.

Any kind of playback device is, by necessity, a filter of information.  People choose the filters that provide them with the kind and quantity of attention they desire, though often this choice means simply accepting something that is there or recommended, and not turning away or falling asleep.

Thursday, April 12, 2012

Marantz 2270 vs 2275: tone defeat

One of my key issues with the Marantz 2270 receiver that I purchased in 1974 was the lack of tone defeat.  Actually, I didn't notice this problem until 1978 or so, when I did some testing and found that the preamp section in this receiver did not have exactly flat frequency response.  The response goes to the extremes, but showed a bit of variation in-between related to the tone controls not being nulled exactly.  When you put the tone controls at the top position, not only are they not switched out, they are not necessarily providing flattest response.  That might require a position just a few degrees left or right from pointing straight up.

Well, that did not leave me with a good feeling.  I had previously discovered that the detents on the tone controls are just that...detents.  These controls are normal potentiometers, not stepped switches.  That had already made me feel ripped off.

Other extremely expensive preamps may have used stepped switches.  I wonder about the Marantz 7's.  It looks from this picture that the 7T does use stepped controls for tone controls, and I think that is true of Model 7 (tube) as well.  Dynaco had a special trick, where when you put the tone controls straight up, they contact a special pad in the control which provides flat response.

Now I see that the model that was replacing the 2270 just at the time I bought mine, the 2275, does in fact have tone defeat.  Back in the day, I had figured that tone defeat would only reduce tiny amounts of noise or distortion by removing an extra stage, because I figured my tone controls set straight up were already providing flat response.

Lack of flat response may indeed mean that comparing two 2270's you might hear slight differences.  And you might prefer the one with less flat response.

Not to be confused with Marantz 2110

I visited a friend in the late 1970's who had just gotten a new set of hifi gear that he must have thought I would finally respect.  Before that time, his audio systems were all-in-one integrated systems made by, or at least labeled for, companies I'd never heard of, and I knew all the major Japanese manufacturers.

He had a Marantz 2110 tuner.  I saw the scope and thought "oooh, this has to be good."  At the time, I myself was using an older and probably not much differently performing tuner in my Marantz 2270 receiver.

But I was very disappointed by the tuner.  It didn't seem very sensitive, and the scope didn't seem to do much.

It was a very different animal from the 2130 I now own.  I think Marantz made a mistake in making the 2110.  Previously, all the scope tuners made by Marantz were exclusively their highest end models.   The 2110 became the one and only exception, a low end tuner with scope.

But many people might not have known this was only a "cheapie" from Marantz, and assumed this was simply the poor performance you could, at best, expect from Marantz.  So I think it was a mistake for Superscope Marantz to make the 2110.  It sullied the brand image.

Right about the time the 2110 was being sold, I was listening to a lecture about high end audio given by Ike Eisenson.  He loved to use the word "mid-fi" to dismiss mainstream audio products mostly made by Japanese manufacturers.  I later worked at his business, Audio Dimensions, for a half year.  During that time, staff at the store identified a giant killer amplifer, the Nikko Alpha III, that we (then) preferred to the sound of Threshold amps.

I think by and large "mid fi" is an unfair put down.  Most of the electronics so labeled, like old Marantz receivers, isn't really that bad.  (Though early 22xx marantz receivers lacked tone-defeat to get honestly flat response, IMO meaning you could fairly say they were mid fi, though they had the separateable preamp and power amp sections--a very rare feature among receivers, so you could simply bypass the preamp.)

2130: My new reference tuner?

Well, no.  But it may become my living room tuner for the forseeable future, or however long it is that my favorite station KPAC is operating at lower power than it used to have.

Unlike the Kenwood 600T, the Marantz 2130 is a nice sounding tuner, with analog-like sweetness.  It also has good quieting, I found a week station that was significantly quieter on the 2130 than my reference Pioneer F-26.  Since I use different antennas, this was not a conclusive test, but it shows the 2130 is in the ballpark, and actually could even have better quieting for weak stations, which is what most people mean when they say Sensitivity.  I am not finding this tuner to lack sensitivity or selectivity, contrary to David Rich's observations.  WRT selectivity, the "wide" has enough of that for most purposes.

But one way the 2130 is definitely superior to the F-26, for me, is the control interface.  The F-26 is a weird statement piece, with only three controls in front: power, tuning, and <?>.  No mono switch, you set the stereo threshold in back.  No muting switch, you set the muting threshold in back.  Actually, in a number of ways, this unique interface makes sense, and would particularly be desireable in some family or public situations.  It may also reduce the number of switches in the signal path.  But it's not very flexible and convenient.  And, the F-26 has no blend or filter switch at all.

That's where the Marantz wins.  It has every popular control on the front panel.  Including a very nice working blend switch makes stereo on KPAC tolerable.

Last year I had started working on a special stereo filter for the F-26, a notch-blend filter that would filter out the 10,000Khz tone in the L-R of KPAC.  Now the 10K tone is less of a problem, the problem is mainly weak signal.  So a plain old high blend or blend switch might be just the ticket.

I should probably figure out how the stereo filter on the Marantz works.  It does not seem to reduce highs at all, and I like that.  So what is the "cutoff" frequency and depth of blending that Marantz uses?

The Marantz also has a level control on the front panel.  I think it's best used as an attenuator when you are tuning only.  Otherwise, if you set it more than 10dB down, you can get noticeable shift in stereo image, just as with all but the most expensive potentiometers.  I myself now have no "pots" in my three main audio systems.  Attenuation is done in the digital domain, perfectly, and with perfect balance.

The volume control is nicely smooth and totally quiet though, so nice to use.

The scope is very nice to use for tuning and stereo checking.  It's about three times the area of the scope on the 20B.  Just yesterday, I lost a bid for a Kenwood KC-6060A, a small scope intended for attachment to an audio system.  The unit is from the early 1970's (it matches the Kenwood KT-7000; I had one of those 12 years ago that drifted horribly) and not refurbed, but sold at auction for $750.  You could easily buy used lab grade scope like Tektronics for that much money.  A way more powerful scope.  But it wouldn't fit so nicely into a hifi system (I have tried).

I paid $950 for the Marantz, fresh from authorized service center alignment (which seems to have been OK).  So, at worst, I got a very excellent tuner thrown in for $200 with my scope.

Marantz 2130

Good sound, good looks, nice control set, scope.  What more do you need?

The 2130 combines the virtues of a capacitor tuned input, like most so-called analog tuners, and a low noise pilot cancelling MPX, like most digital tuners.  This is also part of the formula that makes my ultimate tuner, the Pioneer F-26.

Just in a few minutes testing, I can only say performance is ballpark with the F-26.  Probably not quite as good, but I haven't tested side by side on the same antenna, and that would be required.

Sound musicality is good, I can't say how close it is to F-26.  But still, it's a better sound than most varactor tuners, I can tell that right off.

This is an accurate sounding tuner.   (Make sure deemphasis switch is out, and it confused me for 30 minutes because with front volume turned all the way down, switching deemphasis out made the sound go away because the level control only applies to the normal deemphasis.  I played with the volume control, but only with deemphasis pushed in.  So I figured both the volume control and the deemphasis switch were broken.  I figured for all that time I would need to return this tuner, maybe for full refund.  Or fix it myself, but then I took the time to read the user's manual I found online, and understood why these things were working as they were.  So I have no good reason yet to return this tuner.  If you have pushed in the deemphasis switch, you will get very bright grainy sound.)

So it is not at all like the 20B, which I consider more of a musical instrument, accurate only in an outsized way.  But like the 20B, the 2130 has soul, warmth, as good tuners do, just not quite as much as the 20B.  At the margins, the 2130 has more 20B'ish character than the F-26.  The F-26 achieves its musicality with a neutral (relatively soft compared with Kenwood) softness.  There is more unique character in the 2130 than neutral softness.

If I didn't have F-26, I could make this my main rig.  So it's perfect for my intended application in Kitchen or Bedroom.

Wednesday, April 11, 2012

The early "transistor sound" and my experience

I made my first transition from tube equipment to transistors in the early summer of 1974 when I bought a Marantz 2270 receiver to replace my very ailing set of tube components: a Dynaco SCA-35 integrated amp, a Harman Kardon Award Series tuner, and a Harman Kardon mpx adapter.  I believe the Marantz (which was soon to be replaced by 2275) was on sale for $399, and I found the low price compelling.

I guess I figured old tube equipment wasn't worth repairing.  In fact, the SCA-35, which I donated to my sister, refused to be repaired and I ended up buying her a nice low power Kenwood amplifier by the following year.  It randomly made noises like a frying pan noise.  Even after spending over $200 (which I considered a princely sum) for repair, it went back to its old habits fairly quickly.  I brought it to what appeared to be a professional looking audio repair center on 30th Ave in San Diego.  When we brought the amplifier back, the cranky and snobby repairman said he had done what he was asked to do, the amplifier was fine, and if I wanted anything more I'd have to pay more.  This was a fine amplifier, he said, suggesting I should appreciate it much more.

The tube tuner/mpx setup had delivered a tiny bit of separation way back when I first got it in 1971.  In fact, I had used my Fisher FM80, my very first hifi component, with the MPX first, but when I got the HK tuner I had a matched set which seemed to work better.  But by 1974 there was not only no separation, there was hardly any output at all either from tuner or mpx.

I had long planned for the transition to new gear, studying brochures, thinking about what I might buy.  I had several possibilities in mind, the leading contenders were a stack of transistor Dynaco gear (AF6, PAT5, Stereo120) and the best Marantz receiver (Model 19).  I asked the audio repairman which was better and he said, "There's no comparison."  Well that didn't help, so I asked again, and got some insult.

The 2270 was not so much an item of audio lust as practicality.  In one fell swoop I'd have all new hifi, brand new and working, and transistorized (which was seen as a great virtue then...I had not yet been exposed to tube worship, though that came just a few years later).

First, I didn't one of the noisy pushbutton switches and took it back for repair.  It came back exactly the same, but the problem went away quickly.

Then it also seemed like the bass, the great liquid wonderful bass that I had with the SCA-35 was gone.  Now I had very dried up sounding bass.

That really bugged me for awhile, but gradually I just forgot about it, and the new bass seemed normal and real sounding after awhile.  I used a pair of Large Advent speakers.

It turned out that my SCA-35 was actually exaggerating the bass due to several faults. After it was repaired, it was much more like the 2270 in sound.  If I had not accepted the sound of the 2270, I might have immediately become a tube freak.

I wonder how many times people have decided one type of gear is better than another based on faulty samples.  And once one has taken up the tube dogma, it becomes self-reinforcing.

Now, with my Marantz 20B, once again I'm hearing an exceptionally dynamic performance.  I don't believe this is entirely accurate.  It could be that some of the extra expressive dynamics are actually resulting from a somewhat deteriorated power supply.  Such unregulated supplies can motorboat (enhancing bass), sagging voltage can cause higher distortion in the highs (zing!), etc.

Tuesday, April 10, 2012

Vintage equipment, tone pleasantness, and missing information

I'm continuing to enjoy Marantz 20B right now in background playing KPAC with extreme passion (enhanced dynamics?) and sweetness (low cut off?).  I still don't feel it provides an accurate reproduction, which is supposed to be the sine quo non of audio, which is also called "high fidelity" as a result.

Especially for background music, which is the kind most non-audiophiles enjoy almost exclusively, or even foreground music for serious dedicated listening, I believe a rarely mentioned quality is #1.  Tone pleasantness.  (Even the normal phrase "tone quality" obscures the fact that it's not fidelity, it's the fact that the tone sounds pleasant as opposed to irritating, annoying, grating, etc., so I've added the qualifier pleasantness to highlight this particular aspect of the tone.)

It is tone pleasantness that many listeners seek out to find within their favored equipment.  Tone pleasantness is something you may be more likely to find in older "vintage" equipment than new equipment for various reasons.  Vintage equipment is usually not (with rare exceptions, like FM tuners between 1960 and 1995) where you find the best performance overall.  It is not likely to excel in being revealing of component faults or obscure performance details.  It is not likely to have more slam.  But it can have, by some subjective standard, better tone pleasantness than something newer.  Easily, by simply not reproducing obscure details that have an unpleasant sound.  Some old equipment simply can't because the technology to achieve suct detailed sound were not available at low enough cost.  On the other hand, certain old pieces may have been designed to obscure unpleasantness, or highlight the more pleasant aspects.

Now I think the 20B does a little of both.

Type A audiophiles have the sense that audiophiles who haven't progressed past the pleasantness of the general tone are missing a lot.  Their lives would be much more fufilled if they could experience the audio ecstacy of truly accurate reproduction.  There is so much to be experienced, and equipment which only provides pleasant tone (whether the source is actually pleasant or not) are missing a lot.

According to audiophile canon, there is vast information in musical performance, and even the best equipment doesn't give you all of it.  For the fullest experience, you should have access to as much of that information as possible.

The problem with this for most non-audiophiles and many audiophiles as well is that reproduction of all that information is often unpleasant.  Sometimes the unpleasantness is begins with the original music, but the equipment somehow enhances the unpleasantness.  Other times, the unpleasantness is actually in the equipment.  Sometimes purposefully making something to convey as much information as possible has a tendency to make the previously obscured details unpleasant.

One of my audiophile friends, S, says that people shouldn't bother trying to figure out if reproduction is accurate or not.  Instead they should just find something that sounds good to them.  But this is not a matter merely of being flavored to their taste.  He says that something that sounds good to people *is* also objectively the best also, that's why it sounds good.

That's a strong claim which I don't see good evidence for.  But no doubt, people should find things that sound good to them.  And in many cases, this does not correlate with revealing the most information.

One thing overlooked is that even in a comparatively low fidelity performance, there is lots and lots of information.  And we don't actually need much information streaming in to make us happy or even give us a feeling of awe.  Just a little may be enough to trigger musical associations and hence extasy.  To much can even shut the exstasy.

Now there are other factors as well in vintage equipment, such as appearance, or social associations.

These factors can't be entirely dismissed.  If you play a piece of equipment because you like the way it looks or because you or your friends created it, or even pure sentimentality, is that wrong?  Whatever gets you to play and enjoy music more is better.  "Whatever works" is my bumper sticker philosophy.

The only error is when such realities are not acknowledged, and instead false claims are made about accuracy and performance that aren't true.  Audio is full of that also, and that's what we must guard against.

Also, audiophiles may not wish to concede that Audio, as it exists now within a capitalist world, is a very bourgeois hobby.  A large part of the hobby is obtaining (somehow cheaply if necessary) expensive equipment, often by its very nature more expensive than what most people use for audio reproduction (though sometimes through DIY or cleverness audiophiles can avoid spending much money).

Within a bourgeois hobby, it's perfectly fine to love something simply because it is old.  Or new.

Audiophiles want to pretend it's "only about the music" so they can pretend it's not a bourgeois hobby.  Yes, and not about the social status, etc.  But it cannot be only about the music.

I say it's about the happiness, feeling good, etc.  The music is part of that, but so are the looks and the scene.

L-1000t specs

Stereo Separation: 71dB IHF, 68dB DIN, 48dB DIN at 6.3Khz

(Comparison: L-02t: 55dB, or 45dB 50-10Khz, but probably not DIN)

50dB quieting
Mono 1.8uV
Stereo 24uV

(I remember when tuners had 1.8uV for 30dB IHF sensitivity, maybe hit 50dB at 10-20uV.  However, these numbers are almost exactly the same as L-02t.)

IHF S/N at 65dBf
Mono 92dB
Stereo? 78dB but improves to 86dB at 85dBf

(*The service manual specs repeat the word mono.  I'm guessing they really meant stereo, which fits the numbers.  These numbers are not as good as L-02T, which shows 95dB in mono and 85dB in stereo.  Note however they probably applied the trick of increasing RF level to 85dBf, just without mentioning it, so the numbers for 1000t are almost in good in mono, and slightly better actually in stereo.)

 THD (non-Europe)
Mono 0.004%
Stereo 0.008%
(50-10kHz in stereo, 0.04%...many tuners go above 1% at 10kHz)

Wide has 73dB alt ch selectivity (as much as many narrows).  Normal has 80dB.  Only 300kHz spec available for Narrow, and Kenwood never specs adjacent channel selectivity.

Normal just a bit more THD than wide.  No spec for narrow.

20-15,000Hz, +/- 0.5dB

OK, now for the killer specs, the specs that kill varactor tuners generally:

Spurious Rejection  110dB
Image Rejection 85dB
IF Rejection 110dB
AM Rejection 80dB

Well not too bad, for a varactor tuner.  I believe the TU-X1 has spurious rejection at 130dB.  The L-02T shows 120dB for everything above except AM at 70dB.  The killer is the image rejection at 85dB.  That's quite good for varactor tuner, actually, but just doesn't compare to L-02T at 120dB.  35dB worse. That's the measurement of how well the tuner rejects unwanted image products.  That causes overload in severe conditions probably not of much importance to me, but also constantly adds small amounts of distortion that need to be filtered away downstream.  The L-1000T does suprisingly well at that filtering out downstream.  By the numbers, it looks about the best MPX performance ever, which is all the more fantastic given that it doesn't have the best front end ever.

Some crazy guy (see my sidebar) used an T-85 as a multiplex adapter.  Imagine using a L-1000T as a multiplex adapter on a fantastically good analog tuner.  I could use it on F-26, which is fairly fantastic down to the detector, and even all the way.

AM rejection, FWIW, is better than any analog numbers I've seen, but I don't think that's a good measure of susceptibility to EMF pulses, which generally ganged capacitor tuners do much better than varactor ones.

But will it have soul?

I think ultimately I will have very narrow beam antenna set up.  Meanwhile I usually use folded dipoles which don't give maximally strong signals and are somewhat directionally sensitive.  So the front end limitations are probably not a problem for me.  But I do notice random clicking sounds from varactor tuners more.  The XDR-F1HD is the champion clicker.  But I'm pretty happy with high end varactor tuners like KT-6040 especially.  But I already have F-26 tuner which gives me both air capacitor top shelf RF performance, and the grown up MPX performance which wasn't available until, well, the F-26 (wasn't the L-02t later?).

So here's the sad part, in a way.  It looks like the L-1000t may improve on the KT-6040.  But perhaps not so much on the things that represent the weakest part of the KT-6040, it's mediocre RF performance ultimately limited by being a varactor tuner.  It simply can't reject mixing products, or ultimately EMF pulses, as well as an air capacitor tuner.

So I'm really coming down on the side of Anonymous Dave and his fairly quick dismissal of this tuner.

So about the only question left in some people's minds might be why I bought this tuner.

But I'm going to finally throw a catch.  One part of the audiophile canon is that the front ends of things are most important.  I would agree that this is disproportionately true, and completely true in certain cases, but not always or generally true.

For example, take distortion.  If a front end adds distortion, it cannot be removed.  (Well, sometimes it could be...)  And further, following stages will accumulate distortion on the distortion, so generally give two stages A and B with A having lower distortion, you will get less distortion putting A first.

But this presumes that you only have A and B to work with.  It may be, that you don't have A, you have V, which has a tad more distortion.  But perhaps, either in theory or availability, V as stage one permits the use of a following stage M which has far lower distortion than B.

The approximate number is the product of the two available numbers.  So if using a slightly higher distortion permits using a much lower distortion second stage, AND assuming the second stage was a significant contributor (! which may be a catch here and many other cases !), you can make a better product by improving the second stage.

And those are the choices that are left to us.  We might like to have a most excellent tuner front end combined with the best available mpx, but unless you can build that mpx adapater, pretty much you are stuck.  Available mpx adapters are either ancient history, or perhaps not the best chips.  The best of all mpx are those within tuners such as the L-1000T.

OK, now that I've made this argument, let me say that I have not yet fully accounted for the nature of the pieces of the tuner.  And when this is added up, the full benefit of the front end is hidden because the specs wrt the multiplex section are measured under laboratory conditions.  Even a tuner with a 60dB stereo S/N specification like the XDR-F1HD can sound perfectly quiet, if it only stays at 60dB.  That's the rub.  RF is a jungle, and you need good RF stage to keep that jungle out, and the MPX specs are not really telling you how well the tuner can do that, even when there is no apparent problem, images are finding there way into the audio and adding invisible noise and distortion, invisible because it is "masked" but adds a greyish or grainy quality to the sound.  It is not hard for the percentage of distortion passed through the mixer to be far greater than that of a decent mpx section.

We'll see.  I actually thought the KT-6040 was a fine tuner, and the benefit of the F-26 was, well it was not the sort of thing that would be described by the apparent noise.  The F-26 has soaring musicality, as do the KT-8300 and Marantz 20B in their ways.  The 6040 was less fun to listen to, just a nice quiet tuner.  The F-26 shared the quality of the 6040 that it is harmonically accurate (unlike 8300 and 10b) and quiet (in the cast of 6040 it is apparently I described in previous paragraph.)

Would be funny if the 5 gang Marantz 2130 had more musicality than L-1000T.  Like the F-26, the 2130 is a late generation analog tuner with a mpx similar to later digital units.

Monday, April 9, 2012

Tuner rolling over the weekend

When the weekend began, I was listening to Marantz 20B, which has an incredibly sweet and passionately dynamic tone.  I believe has some sort of "tunefulness" coloration, it's not accurate, I think, but an enhanced rendition.  It's also fun to spin the tuning knob on (provided the muting works...mine doesn't...or you can quickly change volume...I had lost my Tact remote control for awhile and had to kneel to change the volume).  I had my remote on hand late Sunday night then really enjoyed a roll around the dial, ending up often at rock stations I would normally find unlistenable.  But the 20B makes everything sound good, and entices you with that scope to explore the dial some more.

Late Saturday afternoon, I had heard about the 3rd big pop through the speakers while playing the 20B.  This unit definitely needs a full refurb soon.  The power resistors I can see through the casework at the back are black and charred.  Fearing damaging my 20B from playing too long, I switched over to the Kenwood 600T.

At first, it was horrible.  The 600T sounded quieter, actually, but grainy and sometimes slightly strident on the now weak KPAC.  Even later, it was not rewarding to listen to.

I realized then that the test was unfair, since I was running the 20B through my Tact analog input, which sees a 16 bit digital converter with 0dB at 1.5V, while I was running my 600T throught a MSB 24 bit digital converter but which has 0dB at 10V (professional level).  Although I had thought this gave an advantage to the 600T, possibly I was wrong.

So I plugged 600T straight into the Tact, and it did sound a lot better.  But still lacking the sweetness and passion of the 20B.

Well, then, I got to thinking, I have this great Pioneer F-26 supertuner, why am I not using that?  Well, it's a long story, but I had set up the Kenwood 4 months ago so I could track the progress in getting KPAC back to full power.  After 4 months, it still hasn't happened, and I can't get quiet stereo anymore (with 40dB signal I only listen in mono).  So, without moving the Kenwood out of the pile, I could just hook up the F-26 mostly and test the signal only once and awhile (and call KPAC as soon as I can remember to do so).

So I hooked up the Pioneer, and it was far far better than the Kenwood.  It had very sweet and passionate tone, but also realistic highs and bass, so it is better than the Marantz.  It still can't top the 20B for passion, which I'm sure is an illusion anyway, and one that could actually become tiring, I think (though I haven't pushed it that far yet).

So now I was running F-26 through 16 bit converter.  I didn't like that idea, so I decided to hook it up to my Lavry AD10 24 bit converter.  But that had previously been dedicated to my Denon  5900.  So I got out my dB systems 5-selector box.  Oh, yes, that little box with rattling cover.  So I finally fixed the cover by putting Scotch clear duct tape underneath.  When the box is put together, the tape keeps the two pieces from chattering against each other.  Worked great.  So I hooked up the F-26 to the box and the box to the Lavry.  I'm using the Cardas wire between the box and the Lavry.  I'll have to get another nice wire to hook Denon 5900 to the box next time I want to use that.

After all that trouble, I wasn't sure if it actually sounded better going through the Lavry.  It had sounded OK even going through the Tact with it's inferior digitizer.

Later on Sunday, I decided I wanted to play with the 20B some more, so I switched back to the Tact analog input it's connected to.  I rolled around the dial, but then noticed that as I was playing some rock stations, quite loudly, the servo-lock light on the F-26 was going on and off.  I found that I could keep the F-26 from doing that by muting the system, so it was not being caused by direct radiation from the Marantz itself.  But I have never noticed it before when NOT running the Marantz, so it is a bit of a puzzle.  I'll have to watch for this in future.  I'm not worried if the Pioneer goes out of servo lock when I'm playing the Marantz, I just don't want the Pioneer going out of servo lock when I'm playing the Pioneer.

Back on Thursday, I had gotten angry that my 20B has only a tiny scope.  (It's probably made even worse by the fact that mine needs to be adjusted for bigger trace.)  I looked and determined that most of the other Marantz scope tuner used a larger scope.  The ones worth having would be the 10B, 150, and 2130.  The 120 is a poor performer, it is often said (but may be incorrect) that the problem is that Marantz was not using the ceramic filters in the 120 IF strip, all 8 of them, at the correct impedance.  I think I've read another version in which Marantz was attempting to build a balanced IF strip (with 4 sections, therefore 8 filters) but the filters that Murata supplied were not stable.  Anyway, I don't care to own a 120, but I'm interested in the others.  The 150 is interesting because Marantz went back to using LC filters, just as they had done in the 20B.  So the 150 might have some of the 20B sound, and in fact that is what some people say, some like it better than any other Marantz except the 20B.

 The 2130 is interesting because it may be the best performing Marantz scope tuner.  It has the best specs of any Marantz tuner, lowest noise and distortion, somewhere in between a Kenwood KT-8300 and the lousy sounding 600T.  It's the first Marantz tuner with wide and narrow IF selection.  It has a pilot canceller, the first Kenwood to have that was the KT-917 which replaced the 600T.  It has a quartz lock circuit.  So it has features and performance of a good digital tuner, but it's an analog tuner with scope.  Radio-X says it's one of the best tuners to modify for DX'ing, the filters in the narrow strip can be replaced with Ammons filter modules.  Then you have it all, super narrow IF, quiet MPX with pilot canceler, and scope.  Well, you may not have the best sounding tuner, and the front end might not be as good as the best.  It's a dual RF amplifier design, sometimes those have more IM3 than single RF designs (though, they can also be more sensitive too).  But some people, notably Ben Blish, say the 2130 is also the best sounding, as well as being the best performing and the best looking.

Despite all this, and the fact that I find the 150 rather ugly, I actually wanted to get a 150 more than a 2130, on the possibly slim hope that it might have more of the 20B magic.  But I didn't like the $999 buy-it-now unit, seemed overpriced.  A unit on auction had a current bid of $350, that seemed more hopeful.  Meanwhile, I noticed a 2130 was being sold by a Marantz dealer and authorized service center.  They said they had just aligned the 2130 and it was working perfectly.  Well that seemed better than most of the barely-functioning stuff you get on eBay, so I decided to buy-it-now.
Doing that, I told myself I'd still get the 150 on auction if I could still get it for less than $500.  I didn't bid until Sunday though, because I was also thinking about getting a turntable and some other things, and I was wondering if my Marantz madness was now definitely going too far.  How many Marantz scope tuners does a person need to have?  (Well I've spent hours in the past week reading AudioKarma blogs where it seems like the average guy has at least 3 of each one.)

Then, tooling around, I discovered one of the ultimate ultimate and rarest of the rare tuners, a Kenwood L-1000T, for sale at Audio Extasa in Europe.  I've been looking for one of those since 2002, and never seen one on eBay.  I think it's similar to the KT-6040 which is my 2nd best tuner (after the F-26) but better, it's the deluxe version of the 6040 and it has an analog multipler MPX similar to what Kenwood put in the famous L-02T.  So I snapped that one up too.

Two tuners, including possibly the best of the best (even if Anonymous Dave at FMTunerInfo doesn't say much about it), but I still wanted the 150.  So I finally put a $500 bid on it, and as the bidding was ending I finally bid $620, which set the final price to $630 for the winning bidder.

Probably good thing I lost that, buying too many tuners in one week might not be good for your health.  There are always more 150's for sale.  Who knows when I'd ever see another L-1000T?

And I've still been thinking about turntables.

Friday, April 6, 2012

Experiments on Linn Valhalla with Panasonic SG

I'm pretty sure now my stylus is OK.  I've played the pipe organ record over several times and it sounds the same (slightly distorted) at the very end.  It doesn't sound like mistracking, it sounds like the distortion is in the recording itself.  It always seems like organ creshendos occur right at the end of the LP.

I tried running the strain gauge cartridge straight into my ADC.  It works if I crank up the digital gain on the ADC to +15dB, and then also crank up my main Tact to +6dB, I get reasonable volume.  It sounds very clean, but it's noisier than through the tube preamp, and the noise has a distinctly edgy sound like digital aliasing.

So it appears this cartridge does need to have about 30dB of gain for comfortable use, or about 24dB minimum, and the preamp does have to be fairly low noise.  Just judging from these facts (I didn't do any measurements or web searching yet) the Panasonic cartridge requires about as much gain as a moving magnet phono cartridge, and it must be very low noise amplification.  The equalization is very different, the bass rather than treble is attenuated.

I tried using a nice transistor preamp, an Aragon 28k, but it wouldn't work as the 28k is direct coupled and the strain gauge runs on 7.5V bias supply.  I could add two caps in line, but for now just brought back the tube preamp.

I also tried using my Michelle clamp.  It made the sound duller.  I think that is because it is reducing resonances, so the dull sound is really more accurate, in fact it made me think immediately of the sound of my Sony turntable where I use the same clamp.  But it also added a mechanical quality to the sound.  I think that is because the resonant platter and bearing then become better coupled to the record surface.  The felt used by Linn is very thin, about 1/4 the thickness of typical felt cloth, so there's not much there for damping.  I think the Linn strategy is to keep the record from being perfectly coupled to the platter to reduce noise.  The felt damps the record very slightly, and protects it, but that's about all.

Overall, I think the clamp made for slightly better sound, though it's a mixture of plusses and minuses.  A lighter clamp combined with a different mat might would probably be a better solution.  With the existing mat, the improvement gained with a clamp isn't worth the effort.  The super soft suspension makes it a pain to put the clamp on and off.

Not messing with clamp makes playing records much easier.  The Linn is designed in such a way as to make clamp pointless.  It's really not a high fidelity product, seeking the highest fidelity.  It's a lifestyle product, whose point is to encourage you to play lots of records, by making the record playing process very simple, and tuneful, but not necessarily accurate sound.

Wednesday, April 4, 2012

Nostalgia Equipment, is this wrong?

Right now, I happen to be listening to my as yet not refurbished (but functioning) Marantz 20B.  In mono, which I am  now forced to listen on every tuner because my favorite station is being rebuilt, the 20B gives a nice quality to the signal, somehow rendering the noise in a disconnected way from the music.  Technically, I don't believe the 20B is nearly as good as some of my other tuners, such as my Pioneer F-26, Sony 730ES, Yamaha TX-1000, or Kenwood KT-6040 or KT-8300.  But it has a certain quality that makes now-weak KPAC sound pleasant.  And it's cool to look at and operate.  And I'm glad to have an excuse to use it, given how much I spent on it.

Anyway, I was very entertained by this blog on classic equipment including many authoritative (and not necessarily credentialed) people on Steve Hoffman's blog.  The original poster complained that when he took his nice Rotel amplifier in for service, the technician was working on refurbishing a whole bunch of old Marantz low power receivers like the 2220 and wasn't interested in fixing his Rotel.

I just broke out laughing in several places reading that blog.  It's so funny, on the one hand, to see the high and mighty fallen.  Rotel may not be so high and mighty, but it's just the general idea, you may have met as many audio snobs as me.  On the other hand, I very much identify with the preferences of the poster because, while I might like certain super special vintage pieces like the 20B, I think I've moved past those receivers and such, and it does amuse me that people are still there, back where I was nearly 40 years ago.

I myself bought a Marantz 2270 brand new in 1974 from dealer Pacific Stereo, at the new sale price, on something like the first day of Summer Vacation from college.  (Can't remember now, was it $499? $399?).   Price was so low, I couldn't wait any longer, and my flaky tube equipment was developing serious issues I couldn't imagine dealing with, and I was just plain tired of it.  (Though some of the pieces I had have a good reputation now, like the Dyna SCA-35, I have no desire to have them again, particularly THAT cursed unit.  So, no regrets on losing those, though I have had many such regrets over the years.)

I immediately had buyers remorse, sent it back to get noisy switches cleaned, and it came back the same, but the problem gradually went away.  By Christmas, it was my miracle, and I brought it to my girlfriend Jenny's house so we would never be short of great music while I stayed there over Christmas break (while the dorm was shut down).   When college was in session 1974-1975 people came from all over campus to hear my system the first year.  I felt like the boss.

I think the magic was certainly fading by 1976.  I had already been very familiar with what I later knew as high end scene (then, we just called it Stereo, not aware of these class distinctions) having often visited one or more of the three famous high end stereo stores in my neighborhood while in High School from 1970-1973  (Woodland Stereo, Mel Shilling's Music and Sound during its west coast stay, and, retrospectively, I believe it was Steve Zipser's Sunshine Stereo during its brief west coast stay, or someone with about the same attitude...this still seems unreal that I had so much hifi in my neigborhood)  When I bought the Marantz 2270, mainly because of the bargain price, not thinking I could afford much more, I had long debated about buying the Model 19, or a set of comparable separates, or a set of solid state Dynaco separates.

During the summer of 1975 one of my best friends worked for G.A.S., and we had an amplifier shoot out at Andy Hefley's house.  Actually, I didn't get much out of it, I didn't hear any differences between the Ampzilla and my 2270 that I would pay money for.  But of course I felt intimidated and inferior, and I caught the phrase "A series" in the sentence between my friend and Andy:

Friend:  Is this "A" series?
Andy: I don't think so.

I didn't find out what the A series meant until 2010, which I discovered there was a line of Marantz equipment actually made in USA until 1980.  I had figured Superscope had always made everything in Japan, only the old tube stuff had been made in USA I thought.  And of all the ironies, Superscope had relocated to Chatsworth, not far from my old home neighborhood, about the same time as I bought my unit.

 Even in college I was seeing lots of people with separates and things like the Phillips turntable.  I had old Dual 1209 player, with a V-15 III by then, and it seemed like it was making everything sound fuzzy.  I got a copy of Absolute Sound at  a trade show, subscribed to Stereophile and wrote a letter to them.  Stuff like the Japanese Marantz stuff was nearly unmentionable.  Though I worked at a high end store in 1978 as a technician, it was not until 1981 that I bought my first somewhat high-end amp, a Nikko Alpha III (which, long story, had been the darling at the store I worked at, next best thing to Threshold 400A we told customers, what we didn't tell them was that the staff liked the Nikko better, though I don't like it so much now).  I bought it for cash from a friend in a parking lot.  I bought used, and continue to do so, because I have champaign taste and a water budget.

I personally wouldn't be interested much in playing my 2270 now (actually, I have a different one, which didn't get taken apart).  I don't have any systems where it would provide much useful, except perhaps the power amp for surround speakers, and I have other separate amp units available.

I still feel I've been in a different league at least since 1981 (actually, by 1979 I had bypassed the 2270's line stage and was able to swap op amps into a flat line amp I had carefully built).

It may be true that compared to lower priced receivers of the last 30 years, the early 2270's and similar units hold their own in terms of amplification power and sufficiently low distortion, possibly only after being refurbished.

But it's just not for me.  I have Aragon and Parasound amps in my living room and bedrooms systems.  I am using a multichannel Yamaha 5790 in the kitchen, an old Marantz wouldn't fill that role.  An old Marantz might sound as good, but wouldn't have the modern multichannel and digital audio switching features.  I like the built-in equalizer that works perfectly in the digital domain, which can itself be bypassed for straight analog connection to the power amp.

My feeling is that the audible difference between really great electronics, like my Aragon 8008 power amp, and old classics such as the Marantz 2270 (operated as an amp), are not so great that most people would derive about comparable enjoyment from both if not knowing which was actually operating.

Most people don't obsess about small details the way audiophiles do.  Average people appreciate good sound, but aren't going to be able to or want to make fine distinctions unless forced or coached to.

So for such people, there is nothing wrong with a nostalgia piece, or anything else that works good enough.

For type A audiophiles, always pushing toward perfection in every detail, it won't work.

More and more I'm seeing websites of people who are not Type A audiophiles, but more like collectophiles, collecting equipment and rotating it through operation.  Audio gear is as so much toys to collectophiles.  All the better that it have a special story, magic jewel parts, etc.  Audio dealers, the nice ones anyway, are loath to make blanket criticisms of other people's preferred gear, so everything must be "special" in it's own way that some people find desireable.  Things are not better than other things, they are different.  The website of Pitch Perfect Audio is a great example.  Non-dealers, and dealers who are less "nice", often don't mind great put downs of disliked equipment.

Type A audiophiles for the most part will never stop complaining that people must do things the correct way or not experience the ultimate bliss they do.

I have mixed feelings about this.  On the one hand, I think it's certainly true that different people will find enjoyment in different things, and in many ways that's perfectly fine.  And I'm not claiming there is one right way, as some Type A audiophiles do.  On the other hand, bad stuff is often sold as if it were good stuff.  Misleading claims are made.  There ought to be more scientific rigor in audio, rather than just sentimentality.  It shouldn't be so possible to sell BS and fake snake oil in audio, and those are part of the reason there isn't as much progress as there should be.  But maybe progress is overrated, the need for actual fidelity to have enjoyment overhyped.

There's something peculiar here.  Assume for a moment that there has been progress, and at some level in the high end there are now systems far better in fidelity than any in the 1950's (at least any not part of a laboratory).  But imagine two audiophiles, one in 1955 and one in 2005, living with, playing, and perfecting the best equipment of their time.  Which is happier?  Well I think the difference in the actual objective fidelity achieved by these two individuals is of very little importance in this.  Quite possibly, however, I do think they are happiest feeling that they have the best available at the time, or better than anyone they know, etc.  (I am definitely coming to the view that the audio hobby is a microcosm of humanity, and all the things we know in other contexts are there too, and status is one of the big aspects.)

Some say it's the music that counts, but I say, ultimately, it's the happiness that counts most.  The engineering on that isn't exactly clear.