Monday, May 21, 2012

Scoping the tuners

Marantz 2130 scope showing Kenwood L-1000T
Not long after I had the Kenwood L-1000T hooked up to my Sonos system, and was listening to it in the Kitchen (comparing it to the Marantz 2130 I just recently reinstalled in the kitchen) I decided I'd like to see the "Stereo" scope display of the Kenwood.  The Stereo display plots L vs R, so you see a diagonal line when there is mono, and something like a big fuzzy blob in stereo.  It's a visible measure of stereo separation.

So I hooked up the CD-R output of my Yamaha receiver to the scope inputs on the Marantz.  That lets me scope anything playing on my kitchen system, including the Marantz itself, using the EXT mode on the scope selector, but I can also view the Marantz itself using the Audio mode on the scope selector.

Marantz 2130 scope showing Marantz on EXT

It often seemed to me like the Kenwood might show less separation.  (Consider the pictures above for illustration only, they weren't taken simultaneously.)   The EXT Level controls on the Marantz scope are somewhat non-linear, but I adjusted the control so that the scope display looks mostly identical when switching between the EXT display when the Marantz itself is playing, and then to the AUDIO display which is showing the stereo display from the Marantz itself (not going through the Yamaha receiver).  I could get those two to look the same, but input from the Kenwood still looked different.

That is not how it sounds.  The Kenwood sounds like it has just as much separation, and has even more depth.  So is it that the Marantz is separating even what shouldn't be separated?  I'm thinking along those lines.

I believe the Sonos system is doing an accurate job of delivering the audio in 16 bits with no compression, which is how I have set it up (unless it got changed somehow).

Radio Palace

So I have the world's best tuner, Kenwood L-1000T, in my living room system.  I can simply play that system and hear it all through house.  It sounds sweet and transparent everywhere, often drawing me into the living room chair to listen more closely.

And I have Marantz 2130 scope tuner by my fingertips when seated at Kitchen table.  I can play that when I'm at the kitchen table when I haven't turned on the living room system first, or if I want to listen to something different.  An analog scope tuner like this invites you to explore the dial and find new stations.

What could be better?  Well on Monday I hooked the Kenwood variable output (buffered) into the input of the Sonos Zoneplayer in my Living Room.   Now I can play the Kenwood in Bedroom and Kitchen systems as well, connected through a 16-bit digital system.  It sounds nearly as good as in the living room.

Only a few minutes transpired after hooking up Sonos to hear the Kenwood from the bedroom before I also wanted the remote.  So I hooked up a Radio Shack remote extender in the living room, and pointed it right at the Kenwood.  Unlike many other negative experiences with these extenders, this time it worked perfectly right off, and I can use the KT-6040 remote to control the L-1000T perfectly from either the bedroom or the kitchen through the Remote Extender transmitters I have in those rooms.

Not many tuners have full function remotes.  Even though I don't have the correct remote, I can tune new stations in either the automatic or manual modes using the remote control, and memorize them.  Even the Yamaha TX-1000 only lets you select presets, and the Onkyo T-9090 MkII is the same.   I like the way the Kenwood clicks when tuning, has a vintage feel, but I worry if eventually some of the relays will wear out.

Tricks used in removing smell from Marantz 2130

Marantz 2130 reinstalled in Kitchen, now unlit dial
I finished the smell removal process and re-assembled my Marantz 2130 on Saturday night.  By 1am or so I had it set up again in the kitchen, and I played with it until 5am or so, listening to the usual 3 stations plus scanning the dial.  It really is fun to have an analog tuner with scope at one's fingertips, and I think this sounds better than a Kenwood KT-8300.  Which reminds me how way back in the early 1970's people would make fun of the TOTL Marantz tuners as being "Pioneer with a scope."  Well it wouldn't be far into the 1970's when "Pioneer with a scope" would more praise than put down.  Pioneer was known for making good sounding tuners, arguably the best sounding!  The 2130 does in fact sound a bit "Pioneer" to me, not unlike a Pioneer 9500 mkII.  Very dynamic, punchy, musical, open, but also quiet.
Cleaning inside the tuner with Q-tips and Alcohol
Probably the #1 trick in making the smell go away was removing the dial lights.  I was originally going to return the dial light circuit board after cleaning it, but then I noticed I had already cleaned the top pretty well, and the bottom was essentially clean.  So then I wondered, why did it make so much difference to the smell having the dial lights removed vs connected?  Well of course the dial lights generate a lot of heat, looks like 15W or so, nearly half the power consumed by the entire tuner.  That heat drives a lot of ventilation airflow through the tuner, ultimately ejecting hot air at the front edge of the top cover.  Plus, the interior of the tuner is directly heated by IR emissions from the dial light assembly, and gets much warmer.  So the dial lights are driving a process of vaporizing crud inside the tuner and conveying it to the outside, a worst-possible scenario for smell.

I'm guessing that 50-80% of the total progress I made in smell elimination (reduction, actually, but nearly elimination) was from removing the dial lights.  I'm not particularly bothered by the unlit dial, which can be easily read under room illumination.  Eventually, I'll devise a string of LED's for the dial light.  They won't get hot and won't cause the outgassing of smelly stuff.  Funny about the time this tuner was made other manufacturers went to unlit dials.  Famous tuners with unlit dials include the Pioneer F-26 and Yamaha CT-7000.

I'm suspicious that the Marantz repair center replaced all the dial bulbs with new standard replacement bulbs, but the 2130 possibly requires lower wattage bulbs.  I'm just guessing, I felt the dial was brighter than it should have been, but it didn't look washed out either.  The brighter dial was driving more release of smell.  The dial is mostly metal, only the numbers and indicator marks light up through hairline openings in the dial metal covered with blue plastic.  Seems like a waste that so little light should be produced outside when so much light was being created inside.

Now even after running the tuner for 18 hours at one time, I smell nothing right next to it, UNLESS I sniff right where the dial needle indicator light (still connected), jewel indicator lights (for FM and Wide Band), and Stereo light.  There, I can still smell a slight bit of the original smell.  I'm thinking I could make further progress by disconnecting those lights or converting them to LED's also.  Why should a light light up to show you have selected FM?  I've usually selected FM, the separate light for indicating AM is sufficient to know if I haven't.  For Wide Band, it would make more sense to have the light glow for narrow band, to remind me to turn it back to wide band.  In general, lights should indicate things you might want to change, temporary and possibly undesireable warnings rather than permanent situations.  That way, as an additional benefit, they can be off mostly.  My final idea along these lines: change the Stereo light to an "unStereo" light which only lights up when the stereo carrier is too weak to get stereo, or if you have mono selected.  Perhaps a special light for mono selection, once again to remind you to turn it off.  No lites on should mean optimal reception, nothing to think about.

Other things I did:

1) Washed top and bottom covers and faceplate and screws in soapy water and alcohol.  Placed outdoors on sunlit table in afternoon several times.

2) Put chassis on outdoor sunlit table on breezy day.  Turned upside, downside, front, and back.

3) Cleaned off chassis metal with cloths damped with water and Everclear.

4) Cleaned off chassis metal, plastic dial assembly, transformers, backside of two circuit boards facing up, gyro-touch knob and protective plates, and edges and corners of IF and other circuit boards with magic solvent.

"Magic solvent" is Everclear (95% ethanol) with with 1 drop per ounce Thieves' Oil (natural fragrant antifungal) and 1 drop per ounce DeOxit.  I'm not sure if the DeOxit does much good in this formula, it didn't intermingle.  The Thieve's oil is sufficiently light that you can't much smell it much directly, but it seems to cancel out the bad smell, and I think the bad smell may be partly fungal...a fungus eating on the cigarette smoke residue.  Anyway, the smell of Thieve's Oil is very pleasant, so it wouldn't bother me if I could smell it.

5) Removed dial light circuit board, clipping green wires that powered it, bending them so they won't contact anything.

6) Re-washed cover with magic solvent.

As an additional repair, I also put two wire ties from the retaining clip on the front end assembly cover, threaded through slots in the dial assembly.  This holds the wire for the needle indicator light, preventing it from falling on the IF circuit board.  I have previously used only one wire tire, switching to two wire ties seemed to make it a bit better, though still the wire can fall during certain tuning operations to be only 3/4 inch from the board (when I first got the tuner it would drag across the board while tuning), on average, it's mostly suspended by wire ties at the maximum height.

When I cleaned with simple water, I didn't see much coming off.  But q-tips dipped in the magic solvent would quickly get brown cleaning off chassis metal or the corners of circuit boards.  I used up about 100 Q tips.  The underside of the tuner did not get cleaned with magic solution, though I did use water and everclear on cloths on chassis metal.

Success!  The smell is barely detectable, even close up to the tuner after many hours of operation (and I think that's mostly because of the 4 still operating lamps).  And it still works, putting the cover back on has restored normal operation compared with the way it was 3 weeks ago when I first took the cover off.

The tuner runs much cooler without the dial lamps (as shown in picture at top).  The faceplate is ice cold, the cover merely only just noticeably warmer than not after 18 hours of operation.  I think I could put a Marantz wood case on the tuner now.  Previously I worried that a wood case would trap too much heat.  I have a Marantz wood case which might fit.

Tuesday, May 15, 2012


I have been greatly enjoying my Kenwood L-1000T.  On Thursday night I gave it a serious listen, and was blown away, listening in intense sessions until 6am.  It has transparent, sweet, beautiful, dynamic, punchy, musical sound, but also silence from noise.  No apparent information loss from dynamic limiting as with Sony XDR-F1HD.  Completely transparent from top to bottom, unlike Pioneer F-26 which seems a bit veiled at the very top.  Bass solid down to subsonic frequencies.  Nothing unpleasant about the sound at all, and I heard some of the most convincing cello I'd ever heard from any source component.

On Friday night, I continued listening, but discovered that it only sounded right either at a loud level, or a very soft one, with intermediate levels just sounding wrong.  I suspected that my unit did not have deemphasis for US standard of 75uS, but rather for European standard of 50uS.  On Saturday I removed the Kenwood from my system and put the Pioneer F-26 back online.  I was shocked at how much noisier it sounded, I had always thought the Pioneer was one of my most quiet tuners.

Taking the Kenwood apart, I confirmed it had the 0.0082uF capacitor, as required for Europe, and not the 0.012uF capacitor called for in USA.  This tuner is even more beautiful on the inside than the case with dark metal and cast sides.  The main circuit board shown above is large and appears to be made of high quality material and packed with parts, organized in sections.

The RF stage is in a large metal box on the right side, from initial appearances it looks as massive as the RF capacitors on earlier Kenwood high end models like KT-917.  Of course this one only uses varactors and isn't nearly as good, but the rest of this tuner is far far better, making up for somewhat pedestrian RF stage.  Though small the RF stage does use a good single amplifier in a well thought-out design.

Along the left side is a large power transformer, a power supply feature two large and prominently "Audio" labeled power capacitors, and a second switching power supply for the computerized electronics.

I decided it would not be easy either to solder on an additional cap, or remove and replace the cap (though that would be somewhat easier). I am thinking I will get an equipment modifier to make that and other changes for me.  You can see the two brown colored mylar capacitors in the close-up photo below.  All the parts on the circuit board have leads that penetrate holes the board, and are soldered on bottom.  I have dealt with such printed circuit boards before, but I generally find it tough when the parts are packed closely together, as they are on this board.  Boards with surface mount components are worse.  I like modifying point-to-point equipment the best.

The bottom side of the tuner showed no additional capacitors soldered onto the bottom, as is sometimes done for quick modifications. 

Meanwhile, I figured out how to compensate for the european EQ.  I set up a parametric shelving filter in my Behringer DCX 2496 crossover.  Somehow this seemed to work best when I set the F to 2210Hz, with High Pass, but the amplitude set to -2.6dB.  That rolls off the highs above 2210Hz to a maximum of 2.6dB, reaching that maximum around 3180Hz (where the 50uS EQ kicks in).   I set the 2.6dB by ear then determined it would be correct for the frequency range from 2210Hz to 3180Hz, allowing for 6dB per octave slope.

The resulting sound was both superb and accurate.  A friend remarked it was both sweet and clear, my thoughts exactly.

I like having my top tuner play in the Living Room.  I can hear it pretty well in the rest of the house while I am doing things.  I often like background music, though perhaps even more often I like to have it off.  With a good tuner, I like to keep the music on more than with a lousy tuner, it seems.  But when I am playing background music with the L-1000T, it often draws me into the hot seat to hear it up close as well.

When I go into other rooms, but have FM playing in the living room, I obviously don't hear the stereo separation as well, though I hear much about the fundamental tone.  But often the reduced impact from lost separation is just the ticket to free my mind from the need to listen.  If I had the FM playing in each and every room, it might be too much, I'd want to turn it off more often, just to hear myself think.  I'm still working through these ideas.  I have so many tuners, the thought of having a tuner in every room appeals to me, then I could listen with full separation in every room, and also full local control.  But also simply to listen to background music from the living room tuner works mostly also.  I could also distribute music from the living room tuner to the rest of the house using Sonos, and use remote control in any room to change the station.

Thursday, May 10, 2012

Yet Another List of Good Stuff

I stumbled upon this list of recommended components by Chuck Hawks.  Very interesting because he doesn't get into audiophile catfights (in contrast to Type A Audiophiles).  I think (and hope to discuss further soon) that is the correct approach.  When you reach a certain level of quality, our audio knowledge isn't certain enough to be negative on anything, especially since such negativity feeds the Audiophilia Nervosa syndrome monster that afflicts many serious audiophiles.  Someone might well choose not to have a Mark Levinson preamp, for example (there's a long standing audiophile legend which is probably myth that the ML 38 and it's successors are dark sounding) but it's really not fair to  say a guy who likes it has a tin ear, because by objectivist audio engineering standards there's nothing wrong with it.

It looks like a pretty good list for what it includes, through lots of good brands are not even mentioned.  He confesses he is only discussing equipment he is personally familiar with, so it obviously can't be complete.  At the same time, certain brands get blanket recommendations in multiple categories, like Accuphase.  I would agree that you can't go wrong with Accuphase amplifiers, preamps, and tuners, the company created has always refused to make anything but top quality pieces, none of which would be totally out of place in a reference system even today, but has he really tried them all?

In full range speakers, I don't see Revel, Acoustat, Sound Labs, Magnepan, Dynaudio, or many others I'd mention.  Note he does mention the nearly unobtanium KLH 9.

The tuner listing is the best, because the number of super tuners is actually a bit limited, though even there he omits tube-era-Fisher, Scott and Sansui and only one Pioneer is listed.  I don't think I'd include the second tier Marantz like 2120 and ST-5.  Most interesting he does not include Marantz 10B (one suspects he has heard some samples, given the rest of his encyclopedic experience, especially with Marantz tuners, so this omission is an implicit damning) or the 120 (considered a known dog now, though possibly they were better when new and could be rehabilitated by someone who really understands ceramic filters).

Thursday, May 3, 2012

Showdown at the Perfect Polarity Pundit Corral

Above is a picture of a copy of my official Polarity Test 2012 disc (having only the 20 minutes of positive polarity pulses) played back on an Adcom CD player in default polarity mode.  Despite claims by my longtime friend George S. Louis, the Perfect Polarity Pundit, that the Adcom GCD-575 and the NEC CD-730 have opposite output polarity in their respective default normal polarity modes, results identical to the above were obtained in all the tests I performed on Wednesday and Thursday on both players.  And despite his claims that the EZDup Cool Copy CD-6198 inverts audio polarity in copied discs at 16x, in our test on Wednesday night, the copied disc also showed identical results.

The display program was SignalScope Pro demo version (I have mixed feelings about this product, but the polarity test I created was deliberately created to work even with scopes that don't trigger well) running on a 13" Macbook Pro.

We also used the polarity test track on the CBS Test Disc CD-1 and found that the first pulse was positive, and the second pulse negative, on both players in their default polarity modes.  George and others had claimed that the CBS Test Disc was recorded with a negative pulse first.  Presented with this information, Stan Ricker later claimed the intial disc was incorrect but that CBS corrected the disc in later production.  We also made a copy of that disc on the EZDup, and we agreed that it showed the correct polarity on the Adcom and NEC players.  The pulse on the CBS test disc is extremely hard to use.  The track lasts 60 seconds and has merely one up pulse (at 17 seconds in) and one down pulse near the end.   Often, the pulse occurred in the interval between one scan and the next.  But we did these tests over and over until we saw at least one of the two pulses, and on most of the critical tests we repeated the track until we had seen both pulses.

Thanks to George who let me run these tests on his equipment and publish the results, even if they appear contrary to his claims.  He says he only seeks the truth by any and all means.

In the past few years, George, aka the Perfect Polarity Pundit, has generated a lot of online text and emails for his polarity obsession.  He claims to have found that lots of CD players and digital audio recordings themselves vary with respect to a relatively well understood factor known as audio polarity.  Any given audio system can reproduce sound either with correct or incorrect polarity as compared with the original sound.  Correct polarity is generally worth preserving, it is well known that humans can detect the effect of incorrect polarity in at least some simplified and extreme cases according to research published by leading audio scientists in the Journal of the Audio Engineering Society.  But that same published research suggests that polarity is not generally audible over loudspeakers (it's most audible with headphones) and not generally audible with musical content having more than a few instruments playing.  George, on the other hand, believes polarity to be among the most important factors in audio reproduction, and furthermore, that it is often reproduced incorrectly due to widespread polarity errors in CD playback devices, CD duplicators, and recordings themselves.  Many audiophiles have come to believe the same thing, either because of independent discovery or George's influence through his website, emails, and personal interactions with leading figures in audio.  Most of George's polarity testing has involved some kind of listening test, ears and brain being required to perform the test, though he claims some of the tests are essentially objective anyway.  I have disputed the objectivity and reliability of his polarity test methods, and have called for what I consider objective tests using unambiguous test signals and an oscilloscope.

Confronted with scope images like the above, which have so far showed no variation among several component level CD players he claimed had different output polarity, and no changes caused by CD duplication, George says he can't explain my results, and criticizes me for having a closed mind in this regard.  I do indeed see these results as being hard proof that the Adcom and NEC (and, in previous test Oppo BDP-95) players have identical polarity, and that George's finding them as having different polarity was incorrect.  And that the EZDup Cool Copy does not invert audio polarity.  George believes many if not most digital CDR duplicators invert audio polarity based on his results.  I find that idea laughable.  But he has to continue to believe that to support his whole edifice of sighted testing and  anecdotal evidence.  If particular CD duplicators do not invert as he has claimed, many of his findings would no longer fit his polarity story.

Further he claims that the mere fact that I have not yet found a polarity difference among all the players I have tested so far (7 or so, including several George believed to have different polarity) is evidence my methods may not be fully reliable.  [Update: As of Saturday night, we have now found two Memorex portable CD players that do invert audio polarity on all tests.  I have never claimed that all CD players, especially cheap portable CD players, are correct.  A few years ago I found an iPod music player to have incorrect output polarity using an earlier louder version of my test signal and a scope.]

George has years of anecdotal evidence (which he is constantly recounting) and listening tests supporting his views on the polarity of the Adcom and NEC players and many others, as well as the polarity inversion caused by the EZDup and other duplicators.  Not surprisingly even faced with exacting measurements which show the opposite, he is not (yet) willing to change his views.

Also, George has one measurement device which has often, it seems, agreed with his polarity calls.  That is the Galaxy Audio Cricket-R.  The Cricket creates a chirpy electronic pulse in it's line output which it can also read back (either through line input or microphone) to determine speaker polarity.  George has recorded a long duration of Cricket pulses on a CDR to test CD players.  He connects the output of the CD player to a line input he has created on the Cricket by plugging a XLR to RCA adapter into the Cricket XLR microphone input.  It then may show either a green light indicating correct polarity (no inversion), red indicating incorrect polarity, or neither light.  During our use of this device, the "neither light" condition seemed to be the most common.  Faced with neither light lighting up, or a light not as George expected, he would twist the gain control until it showed the light he expected.  On several occasions, it could show a red light at one gain setting, and a green light at another.

I'm not exactly sure how the Cricket works, but even from our limited use of this device on Wednesday night, I would not consider it to be 100% consistent.  If it can be used to obtained different results than my series of positive pulses viewed on an oscilloscope, it is entirely clear to me that it is because the Cricket is inconsistent.  I suspect it was not designed to test CD players.  As it uses a low frequency pulse, it is possible that variations in low frequency response may be the cause of inconsistent results.  I suspect it has been designed to work well with testing speakers but not electronic products like CD players.  It may be confused by the extended low frequency response that CD players have compared with most speakers.  Here is what the Cricket electronic chirp looks like:

But George remains puzzled.  He never stops thinking or arguing how his polarity calls must be correct, implying my tests must be wrong, but he won't say that my tests must be wrong, he just doesn't know.  He cannot believe the Cricket would show incorrect results, especially when those results are consistent with his listening tests.  He continued arguing with me about these results continually from Wednesday until Saturday night, when after some tests on a second polarity inverting Memorex portable player I told him I did not want to hear any more of it.

Visit by Stan Ricker

A friend of George's brought world renowned audio engineer Stan Ricker over for some audio listening and testing on Wednesday afternoon.  It was very interesting hearing his observations and stories.  I wish I had realized that Stan was or may have been the mastering engineer for several of my favorite recordings.  For many years, he produced the Mobile Fidelity Sound Lab special audiophile releases of major label recodings.  According to the web, he was mainly involved with mastering the LP versions.  He might have known something about the CD versions also, one of my favorite CD's is the MFSL version gold disc version of Pink Floyd Meddle.

Like George, Stan is very interested in preserving the correct audio polarity for musical playback.  However his experience and ideas wrt polarity differ in some ways.

Like me, Stan does not believe polarity is consistently audible.  To ensure he gets polarity and other things correct, his mastering system includes an oscilloscope, and he checks waveforms visually.  I also like to use oscilloscopes for various kinds of testing, and have owned and used oscilloscopes since the mid 1970's.  George doesn't own and has only seen oscilloscope renderings on rare occasions, and believes that polarity is so audible that no such tools are necessary.  I don't believe that is true, and it has not been true for me.  Research published in the Journal of the Audio Engineering Society (JAES) suggests that playback polarity is not easy to hear, can only be heard for test signals or solo brass recordings, and even then is much harder to hear on speakers than headphones.  In a real accoustic space, the JAES engineers opined, sound reflections mask the initial polarity.  With real music, the soundfield is too complex for the human brain to sort out correct polarity.  My experience is more in line with the JAES engineers.

Stan knows what the initial impulse of many instruments looks like on the oscilloscope.  Trumpets and drums are particularly good ones to check.

Stan also commented wrt the recording of a Piano.  He likes to record grand pianos with the top removed, because the top causes out-of-phase reflections for a nearby recording mike.  He records above the piano because the hammers underneath the strings drive both string and soundboard upward for a positive initial pulse, which is most similar to what people hear from live piano.  Underneath the piano, the inital pulse is negative, which sounds wrong.  With upright pianos, the situation is different, he records those from the back because the hammers are in front pushing back.

Stan made (or knew of) one recording using a ribbon microphone with some instruments in front and a few in back.  That was the best we to get all the musicians as close as possible to the microphone for the most intimate sound.  Of course that meant that the instruments on the back side of the microphone would not be recorded in the correct polarity.  But Stan argued that the woodwind instruments on the back side did not produce consistent polarity anyway.  He said every other note would be in a different polarity.  I interpreted this as meaning that the same note played twice would not necessarily have the same polarity, there was randomness involved, and Ricker's approach sounded like an acceptable compromise to me.  To George, it was sacrilege, the correct polarity must alway be preserved in recording.  And I found out later that George interpreted Ricker's remarks differently.  He interpreted it as meaning the same note (same frequency) played twice would have the same polarity, but different notes on the scale would be different.  I conceded that if that interpretation were correct, Ricker's method would introduce a potentially audible error, but I still felt it might not be important compared with other factors, so artistic license with respect to was acceptible.  George agrees that people can mess with polarity to achieve particular affects, and that is a subjective and artistic matter, but he doesn't like such recordings, preferring always the correct reproduction of polarity.

Stan said it was also easy to see the correct polarity on recorded LP's with a microscope, and he checked that.

Stan also believed it was best to play mono records in "true mono", using a mono cartridge or summing the audible signals electronically before they reach the speakers.  George said he preferred stereo playback because it puts the groove noise at the speakers but the music in the center, making it easier to hear all the music.  I tend to agree on George with this one.  Ricker said that such playback would introduce all sorts of spurious resonances from unwanted vertical movement into the L-R, causing center image wander and drift.

Stan heard excess highs from the left channel of George's stereo, which has the speaker right against the left wall.  George says he hears no channel imbalance or high frequency reflections, and thinks many people simply image such a defect because of simply seeing the wall.

Overall, Stan seemed to like George's stereo, and spent 3 hours listening to many recodings, including a few of his recent productions which haven't been released yet.  George commented on the polarity he heard in those recordings and the others.  Almost always there was agreement wrt the polarity.  George's friend has generally only spent a few minutes at any visit, claiming he doesn't hear a good center image.  George also specifically demonstrated his newest CD dampers, and showed all the tweaks installed in his system.

Vacation in Tweako Land

As I do about once a year, I am vacationing with my sister and my brother-in-law George S. Louis in their house near San Diego, CA.  Technically it is in El Cajon, but on the north side of Mount Helix.  Mount Helix on the south side is a famous and prestigious San Diego neighborhood known for being the home of many successful creative people like artists and writers.  The north side is similar, or maybe even nicer, though the far away ocean view is replaced by a view of El Cajon and the surrounding mountains.  One of the great virtues of George's home is lack of sound interference or complaint from neighbors since there is considerable distance from them.  It is also very large, 3500 sqft, with an open floorplan that virtually eliminates room modes.  I claim that much of the good and sometimes wonderful sound that George achieves stems from those two hard facts.

He claims that it doesn't matter that he has a large listening room, instead ascribing his good sound to his astute choices of equipment, positional and level adjustments, and the combined effects of all of his audio tweaks, which are now nearly countless.  Such tweaks include custom cables and connectors of outlandish design, equipment covers made of felt (I agree with that one actually because equipment itself resonates mechanically), ionizers, alleged energy field generators or absorbers, black lights, tourmaline stones, damping pads on the top of CD's, CD chemical pre-treatments, 5 second pause protocol ("CD's always sound best when paused 5 seconds first"), polarity correction, teflon or polypropylene film capacitors (I agree with that) having chemical, thermal, or mechanical treatment (but I don't agree with that), completely unplugging major appliances and computers before listening, choosing certain display modes such as minutes-into-track display (not necessarily display off), avoiding room damping but using limited constrained layer damping on equipment and speakers.  George insists that everything except the brand of batteries in the remote control makes a sonic difference, and he has proven all these tweaks to himself and others in relatively short listening tests (mostly without listening to tracks all the way through).  He also insists that measurements are most often misleading.  "Listen to the notes, not the measurements"(tm) is his trademarked motto.

George and I have been friends and card carrying audiophiles since the early 1980's, even before he met my sister.  While we initially collaborated on the use of Linkwitz-Riley crossovers (which he subsequently abandoned) our approaches to achieving audio bliss have diverged more and more over time.  Since we met, he has also gone into the manufacturing and sale of audio enhancement products, sometimes both affectionately and dismissively called "tweaks" by other audiophiles and other recorded music listeners.  (This has nothing at all with the use of the word "tweak" in other contexts; in the drug use world, the word "tweaker" has been appropriated for those who use Heroin.  Well maybe there is some similarity in the fact that both heroin users and audiophile tweakers are addicted to their respective means of achieving bliss.)

George usually has an extremely good sounding audio system usually--better than the average audiophile (I felt it was not up to his usual level of excellence this year, though still good in many ways), as well as a the most extensive collection of recordings of anyone I know.  He also has an extensive network of audiophile friends and customers, and one of the frequent delights of my vacations is visiting other audiophiles with very different audio systems--one of the best ways to learn.

And one of the shocking aspects of George's living room audio system is that despite the usual high level of sonic excellence, at first glance it appears to be little more than cast off audio junk.  The stereo speakers are a two-piece system consisting of a pair of old obscure and unimpressive looking speakers made by AR turned upside down, with another pair of speakers originally sold by Radio Shack on top.  However, a closer examination reveals tweaks and more tweaks everywhere, and most of the tweaks are home spun inventions.  I know from my sister that George spends endless time listening to his system in brief spurts and adjusting it, as best he can, mostly with homespun tweaks based on his own iconoclastic theories.

I concede he has good sound, which has been either better sounding overall or at least better in a few ways than mine.  But I am not particularly interested anymore in trying his approaches in which purely empirical audiophile tweaks with little or no understood audio engineering basis are believed by him to play a huge role.  I contend that his good sound results not from the inexplicable voodoo tweaks per say, but other adjustments and alignments he has also done in his countless hours of adjusting.  And it's not like the actual parts he uses are not fairly good to begin with.  While many tube-o-philes and others dismiss early transistor amplifiers, his Sony 3200F amplifier got a rave review in Audio Magazine when it was introduced in the late 1960's, AR made consistently good speakers while it was still an American concern, and the Radio Shack RCA Pro-LX55 is a descendent of an almost identical speaker which got a surprisingly favorable review by John Atkinson in Stereophile.  These are, in my view, adequate components which can very well if well set up in a wonderful sound room.  Rather than saying, as he does, that the Sony is far and away the best sounding amplifier ever made, a claim that is both iconoclastic and outlandish, I say that amplifiers of adequate quality, and there are many to choose from, sound basically the same so it really doesn't matter which one he has chosen, so long as it is sufficiently powerful etc. for the speakers used.

He says he must have good hearing if he has chosen and adjusted a system to sound so good.  He believes his system to have the best sound anywhere, and he has haunted many stereo shops, visited countless audiophiles, and attended a large number of hifi shows.

I concede he has good hearing.  He has not settled for bad sound, which could easily have resulted from his iconoclastic and penny-pinching tendencies.  But I believe his hearing, like that of most audiophiles, can also be easily fooled into experiencing sonic differences even when don't really exist.  There are tiny random effects, mainly on perceptive attention, that can seem like sonic differences even if the exact sound were reproduced each time.  And the use of memory, since two sonic performances cannot be compared side by side like video screens.  That he can be so easily fooled at the margins is not at all inconsistent with being able to eventually hear real differences when they really do exist.  As intelligent as he is, and his is very intelligent, somehow he can never follow this argument.  Of course he also claims that the improvements that result from his tweaks are huge, huger than those that result from component swaps mainly.  Actually I see his main error not in hearing, which must be good, but in ego, believing in his hearing and every brief listening test he has performed, and not accepting that any of this is random or beyond his control.

One of the best demonstrations of how random our attention and therefore perception of sound can be is given when some orchestras play world premiere music.  Sometimes they play the same work twice.  I have always been amazed how the second playing sounds entirely different.  The first time this happened, I was convinced the conductor was playing a trick on the audience.  But the trick is this: we never hear the same thing exactly the same way.

For a number of reasons, I am not particularly interesting in trying things when I have not a clue as to how they work.  Most often, audio tweaks have either no effect on the measureable performance of an audio system, or a measureable effect so small as to make it implausible that they have an audible benefit, or even a measureable effect going away from the assumed direction of audible improvement.  Quite often, audio engineers would be unable to explain how they have any benefit or even audible effect at all.  I concede that these engineers could be wrong, and there could be many things that improve audio which are either not understood or actively dismissed by them.  However, over time, it would seem to me that if real methods of improvement had been found, these benefits would eventually be confirmed by scientific methods such as Double Blind Testing, and ultimately adopted and explained by audio engineers and scientists.  In my 45 years of audio play, investigation, and reading, I have not seen this happening, and have become sympathetic more to the argument of audio "objectivists" (another word used differently in other contexts; an audio objectivist is not likely interested in Ayn Rand) who insist that audio benefits be proven by scientific methods and measurements.  A famous audio objectivist is Peter Aczell, publisher of The Audio Critic.  I agree with much of what Peter Aczell says nowadays. While most often I think his rhetoric is too harsh, I am also sympathic with his "no more Mr. Nice Guy" feeling.  Especially each time after visiting George, who cannot help but constantly cross examine my audio thinking in a way that seems aimed to find fault with it, and to confirm his own ideas.  I enjoy my visits, but this aspect is annoying.  I would be comfortable being non-judgemental, but when my ideas are constantly called into question, it is hard to be that way.

Audio tweakers and their sympathizers always insist that one should "listen and decide for oneself".  I see many problems with that approach.  In my view, human hearing is not a mechanical process but a creative one.  It is true we can often hear tiny things that would have seemed to be implausible on the basis of common sense.  But at the same time, we never hear anything exactly the same way in two successive listening sessions, even it it is a physically identical playback.  As such, we can easily be fooled into believing that something sounds better or worse, when in reality it has been unchanged.  So if an audio tweak has exactly zero effect, something like half of the time we will find it to make things sound better, and the other half worse.

Phenomena like this, and various psychological tendencies such as "confirmation bias" are well known to scientists, and the reason for controlled methods such as double blind testing.  Non-audiophiles might be amazed at how loath audiophiles are to use blind testing methods, particularly double blind testing.  We haven't actually proven humans can hear the benefit of far out tweaks.  When an audiophile says some tweak makes a huge difference, you should take that with a huge grain of salt if swallowing it at all.

The audible benefit of such tweaks (having no engineering explanation) has not been established by double blind testing.  To establish such benefit requires more than one successful double blind test result (though that would be suggestive) because that could happen as a matter of chance.  If many such tests are performed, but not made known to others, the few successful results that would happen as a matter of chance might get more attention than they deserve.  But in the case of most audio tweaks, except for those now accepted by objectivistic audio engineers, I am not even aware of ANY successful double blind tests, after 55 or more years of audio tweakdom.  If successful results have occured a few times, in all that time, they have not been replicated or published in the audio engineering literature.  Yet they continue to be promoted, sometimes on very bogus grounds.  Thus, Peter Aczell's "No More Mr. Nice Guy."

Many audio "subjectivists" or near-subjectivists declare that they believe double blind testing is an invalid approach, and so they aren't interested in performing them.  Even for those which believe in the utility of such tests, they are very very hard to do rigorously.

To his credit, George does not dismiss and even actively promotes the use of double blind testing.  But does he use them himself?   To his credit, he has tried.  On two separate occasions done my best to perform two double blind tests with George as the subject, on tweaks he insisted had such great impact he could not err in identifying it.  In both cases, my interpretation of the results (and I have quite a bit of experience and even some qualifications in the use of statistical methods) is that they showed no audible significance, and with near-random results to boot.  George's interpretation of the first test we performed in the 1980's was different, but he agreed about the result of the test we did around 2005.  Though rather than change his thinking, he mainly seems to have forgotten about these tests.  Another common approach is to always find fault with such results.  These kinds of responses fit the pattern of confirmation bias.

I well understand that the failure to show statistical significance in any one tests does not prove anything.  The test could be flawed, the listener not sufficiently trained, etc.  This is even more true than in the case of a single "good" result.  What is most damning about audio tweaks is not the failure to find benefit in particular tests, but the failure to find benefits after decades of audio tweakdom.  And also in light of the wonderously huge benefits claimed by tweak sellers and fans.  If a benefit is indeed truly huge, as often claimed, it should be easily proven in double blind tests.

My ultimate feeling about the "listen for yourself" doctrine is that I don't have enough time to try everything claimed to improve audio performance.  I don't even have enough time to try all the things based on well established audio engineering, so why should I waste a lot of time pursuing voodoo tweaks?  Even many tweak fans admit that most tweaks are useless (the countless ones they have not chosen to use or had later abandoned).

Furthermore, I fear that such tweaks, whose method of operation or measureable effect is usually unknown, it could actually be making matters worse.  And yet, at the same time, just as a matter of chance and the variability of auditory perception in listening to music, it might occasionally seem to make things sound better.  If such a tweak is chosen, it may stay in place for years until later found to be sonically objectionable, after years of bad effect and badly influencing other audio tests.  When this is found to have happened, an upheaval results.

Lacking both measurements and scientific validation through double blind testing, audio tweakophiles are hunting in the dark with no compass.  At great effort, in principle (if not merely 45 years of experience) they might find some useful enhancements.  Some fine day.  And just as often, steps may be taken backwards.

I have tried a few voodoo tweaks myself, and I have often let George and others demonstrate them for me.  At times, I have experienced perceived improvements, but none so huge as to make me interested in going down the tweakophile path given the issues and risks described above.

While I don't go for the kinds of tweaks that have no engineering explanation, I do try to use good equipment--low noise, low distortion and wide flat frequency response, high intrinsic linearity, possibly better than necessary based on the limits of human perception.  I seek out low dielectric absorption capacitors, low capacitance or low inductance wiring (the former for interconnects, the latter for speaker cable, there's engineering wisdom behind that).  While I can't or haven't proven these to be necessary, their method of operation is known, and they can be measured and/or categorized.  For example, teflon capacitors are the best because they have by far the lowest dielectric absorption.  So with tweaks like these, there is a visible path forwards.  More Teflon!  Mistakes may be made, but not so much upheaval.

Many might find highly questionable the way I buy most equipment unheard, based on reviews and measurements (and my own thinking about them, of course).  But most often, I have not been disappointed for a long time afterwards, if ever.  I think I would not do as well following the "listen for yourself" doctrine.  Most often in such listen-for-yourself situations, I have found very shortly afterwards I made the wrong choice.  Short listening tests are a very unreliable way of moving forwards.  And that variability leaves a wide opening for voodoo tweaks.

On any given listening session, a tweak that does nothing at all might have a 50% chance of sounding like an improvement, perhaps more if the test is non-blind and one has faith in the people endorsing it.  And if it doesn't sound like an improvement, a seller has another chance by going back to a A after doing A and B.  So it turns out that short listening tests are more often than not a way to sell nonsense, like voodoo tweaks, and not really a way to critically evaluate equipment.  Critical evaluation requires long term listening, measurement, technical and scientific analysis, comparative evaluation, more listening, and ultimately blind testing.  I can't claim to have done much of this critical evaluation.  But I try to move in that general direction, and not waste much time with short listening tests to hear the value of voodoo tweaks.