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Woo WA22 with LCD2 - my tube rolling notes

Discussion in 'Headphone Amps (full-size)' started by jerico, Jan 22, 2011.
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  1. jerico
    This is going to be a bit of a long post, but here's a quick synopsis: I set out to do some tube rolling on my WA22 to see what mated best with the LCD2.  At first, they really did not sound good., I found the amp/can combo to be sensitive to tube changes, but in the end got to a great sounding combo.  It took some work!

    Now on to the details:

    My source is a Wyred4Sound DAC2 into the WA22 with an Audio Quest Carbon balanced cable.  The LCD2 uses a balanced ALO 8 wire Chain Mail cable.  The DAC is hooked up to a dedicated Mac Mini via an Audio Quest Carbon USB cable.  All of my music is Apple Lossless, and stored on an external NAS.  I use iTunes/Pure Music for playback, and use the memory play feature of PM to minimize network traffic issues (the Mac connects to the NAS via a power line Ethernet adapter).

    When I first got the LCD2, I plugged them into my WA22 with the tubes that I had previously selected for my Beyerdynamic T1s.  Off the bat, I felt that the T1s needed a little bass help, so I selected tubes that I found had a little punch: EML 5U4G rectifier, Shuaguang Treasure CV181Z drivers, GE 6AS7G power tubes.

    This proved to be WAY too bassy for the LCD2s.  It sounded like there was no bass control - just boomy bass all over.  The soundstage was very cramped as well, and the highs sounded recessed and muffled.  My first thought was that my amp simply can't handle these cans.  But I did't want to give up, as others on these boards have reported good results with the WA22 (and the WA6 variants).  So... Time to tube roll.

    Thinking I needed to use higher gain power tubes give the LCD2 more juice, i swapped out the 6AS7Gs for Sylvania 7236s (Woo upgrade tubes).  This change seemed simply to make everything louder - to the point that i can't really get beyond 8 o'clock on the volume. And the bass still sounded way too bloated.  I also felt that the 7236 was bringing some noise into the mix.  I reverted back to the 6AS7G.

    Next, I swapped out the Treasures (also Woo upgrade tubes) for some KenRad VT231s.  This was a bit of an improvement - not huge, but they brought out a little bit of treble and helped to very slightly control the bass.  But I still found the sound to be bloated and fuzzy.

    Next, I dug out my Sophia Princess rectifier (yet another Woo upgrade tube).  I didn't like this tube at all with my T1s - it just didn't give them any punch.  But with LCD2s it is perfect - that bass bloat is gone, and there is a little bit of sparkle to the highs.  Not sparkly like the T1 - actually nothing like that at all.  But not recessed or rolled off, either.  And details come through, that were previously being obscured by the fuzzy bass.  And the sound stage widened out (not massively, but it no longer sounded collapsed). This combo sounds GREAT - my first taste of the LCD2 sound that so many have been describing.

    The last step was another swap of the power tubes, to see how thy interact with the Princess.  I threw in the stock GE6080 (which I quite like with the T1, especially for the price - enough that I have a spare pair).  The effect here was minor - not much different from the 6AS7G, but with these I lost a bit of bass, too much actually.  From there, I swapped in a pair of Chatham 2399 tubes (which I am told are similar to 5998 tubes, if not the same).  

    This combo made me VERY happy - the bass reappeared. Not TOO much, but not recessed either.  There's a hint of treble sparkle, but again not TOO much.  Plenty of detail too, with just the right amount of tubey goodness, and nice imaging.  There is still a volume issue - I can't get much beyond 8 o'clock (the volume steps are rather large, so it's tough to get the "perfect" level).  But the tone is awesome.

    I am ending my rolling here for now, as it is time to get back to enjoying music instead of OCD'ing on my gear!  But I do have a Mazda GZ4 en route, which I will tinker with when it arrives. Until then - hope this helps some of you!

    Justin
     
  2. Skylab Contributor
    Very interesting post.  Couple of things for you to consider.  The Ken-Rad VT-231 has the reputation as being a very bass-strong tube.  Sounds like you've managed to get the sound you are after by using the Princess Sophia, which is a bright sounding tube, especially compared to a NOS 5U4G.  One alternative would be to go back to the 5U4G and use a different 6SN7, like maybe the Sylvania VT-231 or if you are feeling flush, the Tung-Sol black-glass round-plate 6SN7GT.  The 2399/5998 is a great tube for sure - my second favorite of all of the 6AS7G varieties.
     
    But if the sound you have now pleases you, then call it good and stick to it!
     
  3. jerico
    Thanks for the info, Sky. I've been keeping an eye out for some TS BGRP, but haven't got my hands on any yet. I'll also look for a Sylvania VT231.

    I do try to avoid tubes that are TOO hard to find though. Once i find something I like, I tend to look for backups right away. That can get expensive in a hurry!
     
  4. jerico
    Small correction to last paragraph - i have a Mazda GZ34/5AR4 en route! 
     
  5. jerico
    I've been using Chatham 2399 power tubes, and I have a stash of them, but I'm noticing that they are a bit microphonic, when paired with KenRad VT231s and the Princess (you can hear mild taps to the tubes themselves, as well as to the sides of the amp).

    I didn't notice this at first. I also tried swapping out the VT231s for a backup pair (same result).

    I the rolled in a pair of TungSol 7236, and these are dead quiet with the VT231/Princess pairings. I still don't love the sound of the 7236s though.

    Maybe this amp doesn't like the 2399? Or maybe the 2399 isn't the 5998 proxy that they are billed as? Or could all of my 2399 tubes be defective (seems unlikely, though possible)?
     
  6. Skylab Contributor
    Every 2399 I have ever gotten looked exactly like the 5998, and measured like one too.  But if you got all your 2399's from the same source, they could all be microphonic.  There are a lot of microphonic tubes when it comes to these larger coke-bottle types - it's just the way it is.  Generally, though, I don;t see why this is an issue.  If they are so badly microphonic that they make noise when you tap on the table the amp is on, that's one thing.  But if they just make a little sound when you tap on the tubes, why worry?  Just don't tap the tubes [​IMG]
     
  7. jerico
    You're right... You're right... I should just keep my paws of them and enjoy it all while they last. I'm going to throw some tube dampers on them and see if I can put it out of mind. They do sound nice, otherwise.

    In other news, I didn't care much for my Mazda (Siemens) GZ34. It was just ok - didn't get my feet tapping much.

    I was just listening to some 24/192 classical and wow, the LCD2s make that something special.
     
  8. Skylab Contributor
    I use the Herbies tube dampers on my GEC 6AS7G's in my WA2.  They reduce microphonics so that I can tap the amp and not hear anything, which is good.
     
    I had the same feeling about the Siemens GZ34.  Too sterile.  I like 5U4G's much better.
     
  9. SDMAN
    2 days ago, I ordered a matched pair of NOS JAN Tung-sol 5998's to use in my soon to be delivered WA22. They look to be in the original Chatham boxes with a date of mid 1963. Also grabbed a pair of NOS NEC 6AS7G's.
     
  10. mikemalter


    Quote:

    Skylab,
     
    Had not thought much about tube dampers up until now.  I used to use them on my tubed equipment when I was listening through speakers, but am doing mostly headphone listening now.  How important are dampners?  I am using a pair of GEC 6AS7G's, but am using a WA22.  Should I be using them?  If so, on all tubes?
     
     
  11. Skylab Contributor
    No need to use them at all unless you want to try to reduce micro phonics a little. It won't make a badly microphonic tube completely better of course, but it can help a somewhat microphonic tube become totally usable.
     
  12. jerico
    Dampeners can be too much of a good thing too - too many of them, or If you put them on the tube in the "wrong" place, can have an adverse effect. I don't really notice them doing much on my Woo with my current tubes (same as above posts) but I like them on my speaker amp tubes (up around the top of the signal/driver tubes).

    On a separate note, regarding my humming tubes - I think I actually had several bad ones, just coincidentally. I've since rolled in some more recently-acquired Chatham 2399s - no hum, they sound awesome. Very happy with them.
     
  13. mikemalter
    I have a matched pair of GEC 6AS7G's and one of them is a little microphonic.  It's no big deal with music playing, but I think I may try the dampers.
     
  14. minimus
    I am using the WA22 and the LCD-2s with the same balanced cable you are using. I find the amp to sound incredibly clean, no muddy bass or truncated highs. The tubes I am using are RCA 6SN7s, Bendix 6080s, and a Mullard 5AR4. I frankly don't find the sound of the WA22 to change that much with different tubes...Sylvania 6SN7s were maybe a little closed in compared to the RCAs. My impression is that the sound of the WA22 is relatively immune to tube rolling..,certainly, no tubes I have tried have created a really warm, enveloping sound. Instead, the amp either sounds clean, dynamic, and holographic or a bit murky.
     
  15. mikemalter


    Quote:

    Interesting as we have such a different experience with the WA22.  I find it very responsive to tube changes which, from my experience, make clear changes in dynamics and tone.
     
    I share your impressions of the amp as being clean with no muddy bass or truncated highs.  The tube set I am using now is giving me that warm, enveloping sound.  I am using for power GEC 6AS7G, driver: TungSol 6SN7G BGRP (oval micas) and an EML for rectifier.  Have you ever had the opportunity to try a pair of BGRP's?
     
    What is your DAC and what is your music source?
     
     
     
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