Monday, February 17, 2014

More turntables, and my Lenco enlightenment

I did have a lot of audio stuff I wanted to do on the second weekend of February.  Typically when I have too much stuff on my mind I want to do, nothing actually gets done.  But not this time.

I started by moving the Classe CP35 preamp to the master bedroom, replacing the Acurus L-10.  Despite having better measurements, and the advantage of a "bomb proof" circuit with attenuator at the input (before any amplification…this may sound obvious but it is not always done this way, and the Classe does not, so input to the Classe must be limited to 3.5V RMS or thereabouts…hence the model number?) I actually like the sound of the Classe better.  Long ago, the Classe replaced the Aragon 28K in my then main system--the bedroom system.  And the Aragon is a far better preamp that the L-10 objectively and subjectively and build-wise.

But the main reason why I decided I needed the CP35 in the master bedroom was that it has stepped attenuation which ensures perfect tracking in both channels.  That's a very important thing if you are making digital copies of analog recordings, which is a main feature of the new "analog pod" at the south side of the master bedroom.  This started with the turntable (currently Mitsubishi LT-30) and the high resolution digital audio recorder (Alesis Masterlink).  But the pod already had my Nakamichi RX-505 (though it wasn't yet hooked up).  And I added a tuner (a Yamaha TX-1000).  These are all top or nearly top models of their kind.  And now they are all hooked up to the Classe CP35 (well, actually the dB systems preamp is hooked up, not the turntable as such).  Also the CP35 sends the audio from whatever is the selected device to the main portion of the bedroom audio system, which is in the northwest corner of the room.

Back in the day when I was using the L-10 preamp, I had simply dialed in the correct gain from phono preamp to masterlink, dialed in the balance point as well (which was not perfectly centered, because of mistracking in the potentiometer).  There was only one thing to record, so that was that, and if I needed to change the level through the speakers I could do that through the main system.

Now standing in front of the analog pod I flip through the different sources either for listening or recording, so it's convenient to readjust the levels for the different sources.  Eventually I hope to memorize the optimal recording levels for each source, and the Classe will make this possible, but even now it's not hard to find a good level (which is much easier than re-discovering the optimal channel balance each time you change the level as is needed with analog volume controls).  Somehow with a digital volume control, even though in principle you can't dial it in exactly, it is much easier to dial in within it's level of precision, and do so time after time.

That work combined with an evening at the Symphony (where they played Dvorak's New World Symphony) made for a good Saturday.  Actually I didn't get the FM antenna set up until Sunday morning.  This was far trickier than expected, high and flat against the wall didn't work well.  I tried several alternatives, ending up with a drooping line across the south wall, which still doesn't work as well as my antennas in the living room.  Which is strange because the bedroom faces my favorite FM station KPAC, whereas the living room is on the opposite side of the house.  The antenna may need more work.

Meanwhile I played a record or two on the LT-30 and copied the Scarlatti recording to CD.  The Musical Heritage Society recording of Scarlatti did not reveal any of the wow that I now believe this turntable has.  Unfortunately, the last recording I played on Sunday night, Rick Wakeman, did reveal the wow and the recording was made almost unlistenable.

I also discovered a wonderful tape inside the Nakamichi and played it many times.  It's a recording of electronic and dance music from KSYM several years ago.  I tried to tune in KSYM on the bedroom tuner and basically it's not worth listening to that way because of high noise in mono only (though I did listen several times).  My best antenna for KSYM is  at the NE corner of the living room, and it is hooked up to the Kenwood KT-6040 which has been turned off because it can't be adjusted right as the display is hidden by other equipment.  It had been in use a few months ago, but then somehow some key adjustments were changed, and it wasn't working right, and I couldn't figure out why, so I simply flipped the Sonos input over to the Pioneer F-26, connected to the best-on-KPAC antenna, and listen to that anywhere in the house.  On KPAC, and on that antenna, the F-26 sounds best anyway.  But that means right now I don't have good KSYM.  I had been thinking KSYM had less power than before, but it comes in fine in my car radio, it's just my master bedroom seems to be in a radio shadow.

Even if KSYM had been coming in well, however, (and I intend to fix that and subscribe to KSYM) on Sunday they did not seem to be playing the wonderful kind of music on my tape, which I listened to over and over and danced to.  So I was glad I had that tape!  Taping FM radio, a civil right which was won in court long ago, is a wonderful thing to be able to do.  You can time shift and even make party tapes and the like!  Note that you don't necessarily have these freedoms with digital sources.  I copied the tape to digital on Monday morning.  It sounds great in Dolby C playback, but I can't remember how I recorded it.  I was thinking of making digital copies with Dolby C, Dolby B, and no Dolby.  I'm also learning about a bunch of artists I'd never heard about before.

Anyway, I was by then into the doldrums of Sunday afternoon, and what to do next.  But I quickly started building the new equipment stack to support the Lenco.  The Krell FPB 300 is forming the base of the platform, with protective felt on top.  On top of that I have Marantz 2270, rescued from the bottom of a vintage equipment pile in the Laboratory.  Turned with the backside forward, and I set everything up for Phono 1 and 2, which I can reach over and change when needed.  Then I took off the Lenco platter and wondered about shipping bolts.  I looked up on VinylEngine and learned that the two red bolts around the motor are shipping bolts, which can either be loosened or removed.

Then without doing more online research, the mounting of the Lenco plate to the plinth seemed wrong to me.  So I removed the two metal plates that hold the plinth on.  Only then did I go back online and fine that those metal plates were part of the Lenco suspension, and without them the bottom panel (a thick piece of particle board) doesn't stay on.  Oh, well, I also found that many people remove the bottom plate and shims anyway, so I did just that.  I put the Lenco with bottom and springs removed on top of the Marantz 2270, which only gets barely warm (about 93 degrees) but I've decided must only be turned on when listening to records.

I also hooked up my second LT-30 to the Marantz receiver, but haven't listened to that much.

The arm on my Lenco has very flaky mounting, it hinges but can also wobble somewhat.  I suspect it has V-blocks in almost useless condition, sort of working but not very well.  It is also missing the tracking force weight and was missing the anti-skate assembly.  But no worries about the M91ED cartridge and "new" stylus (aftermarket) included, I didn't care what happened to them..  I found that I could balance the arm with the weight nearly all the way forward.  So I figured that just pushing the weight all the way forward would give about a couple grams of tracking force, and that would be fine.  (I only learned days later that the M91ED is not supposed to be tracked with more than 1.5 grams of force.)

I took the almost unlistenable copy of Emerson Lake and Palmer Tarkus and played it.  And it was like the first time I had ever heard that record.  For the first time, and completely unlike when I played it in the bedroom on the first LT-30, it made sense musically.

Then I played Peter Sprague Dance of the Universe, and it also sounded more musical than ever before though I'd say the bass player still sounds a bit out-of-tune…but I remembered that exact sense of intonation from the Peter Sprague concerts I went to.

I was expecting some kind of revelation from running an idler turntable again, and especially a Lenco (since I had good experience with Lenco in the 1970's).  But this exceeded expectations.  Not only was the Lenco more musical than any source I've had in years, the difference between it and my currently working direct drives is huge and obvious.

Actually, I think my #1 LT-30 is not working to specs, and it probably wouldn't sound so bad if it were.  But I have to believe that even if it were working to specs, it would not sound as musical as the Lenco.  During the following week, I played records on the Lenco and the #1 LT-30.  Records on the LT-30 sounded ok a few times, but sickly on others (and I think it's getting worse).  Every single record played on the Lenco has been a musical delight and revelation, despite the lousy tonearm and cartridge.

During the following week, I investigated tonearms, and decided to get a 12 inch Jelco SA-750L, mounted in a large base from Moldovia (where an ebay seller lists a large variety of possible bases).  On Friday I ordered the base after assurances that the seller would make it for the 12 inche Jelco and use American Walnut veneer.

Thinking I might like to have an idler automatic turntable in the bedroom also, I bid and won an ebay auction for a nice working Benjamin Miracord Elac 50h turntable.  With the Elac, I will not have to get a new arm.  Of the mainstream changers, I'd always thought Elac was the best, better than Dual or Garrard.  The Elac also features a special Papst motor which has spinning rotor on the outside for less cogging, and it has a platter as heavy as the Lenco if not more.  (The 12 inch Dual turntables also have about equally heavy platter.)  What I really hated about the 1209 I had while in college was the small platter AND the "mat" which consistent of rings cemented to the platter.  Those rings did not support the record very well, and a buzzing record contributed to bad sound.  Well it turns out the 1219 also has a similar looking platter, with integral rubber rings to support record, which I would not want.  But the 1229 has a full platter mat which might be removable.  So the 1229 might be OK too, but they typically go for even higher prices now than Elac, for reasons only of popularity.  I lost a few bids on 1229's, but would rather have Elac anyway.

I then won a second auction for a cheap 50h with no base for spare parts.  The working 50h I won has a modified arm with aftermarket balance dial.  I could replace that with the original counterweight from my second 50h.

On Wednesday I received the shipping clamp for the SP 10 turntable.  On Thursday I sent it to the seller of my SP 10 by Express Mail.  (The seller received it on Friday.)

So my collection of turntables now includes:

Linn Sondek LP12/Valhalla/Ittok (needs motor repair)
Sony PS-X800 (not working)
pretty Mitsubishi LT-30 (has motor problem)
dented Mitsubishi LT-30 (not yet fully tested)
Lenco L75 (a musical revelation!  But arm not fully functional)
Technics SP 10 Mk2a with Obsidian Base and EPA-100 arm (not yet received)
Benjamin Miracord Elac 50h (not yet received)
spare Elac 50h for parts

It remains to be seen whether SP10 or L75 will win the honors of being main living room turntable.  I might keep the other one in the living room also (SP10 for rock and Lenco for classical?) or I might end up putting the SP10 in the bedroom (all the better for copying vinyl to digital).  The EPA-100 arm features auto liftoff so it would make as good a bedroom turntable as any.

On the following Saturday I attended River city Audio Society meeting, which was as wonderful as ever.  This time was mostly playing vinyl records, and Gene had brought his Technics (looked like 1200).  It sounded mostly ok, but I thought I heard some speed instability even before I saw what the turntable was.  Gene said later that the table sounded better than it had sounded last time, when he felt it sounded old and tired.  After that, I got home and played two records on the #1 LT-30.  They both sounded pretty bad, so I'd have to say my LT-30 is actually far worse than Gene's Technics.  (Gene's favorite personal table is a Garrard 301 for which he sold his Scoutmaster.)

By Thursday I was able to set the tracking force on the Lenco with a digital gauge.  It appeared that my original setup wasn't too bad with tracking force just over 2g, but I needed to lower that to 1.5 at most.  Unfortunately the tracking force varies across the record and also at different heights and the gauge itself seems a bit taller than a single record.

On Saturday I tried to set up a replacement tracking force weight for the Lenco using a 5g weight and some dental floss.  I ended up using tyvek tape instead of dental floss.  But rather than allowing the arm to be more stable (so it wouldn't rock but simply hinge), the weight only made the situation worse.  Or I made it worse trying to attach the weights.  I ended up removing the 5g weight and repeating my original setup but with gauge.  But fiddling this much with the arm seems to have made the damping blocks even worse and it tends to rock more easily than before I started trying to use tracking force weights.  What it really needs is full disassembly and repair with new V blocks, but I don't want to bother with all that since it's going to be replaced soon anyway.  But I was strongly tempted to remove the Ittok from my Linn and use that instead.

But instead I got to setting up my super tweeters again, and that makes for another story.

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