Woo Audio WA7TP (tube power supply) Impressions Thread
Jan 7, 2015 at 7:13 PM Post #481 of 1,117
 
So yours is the WA7 that has small movement but the TP top plate is fine?
 
Then I guess it's just variance then.
 
dL

 
 
No...sorry.  To be clear the top plate on my WA7 has a bit of movement.  I thought it was the design.  It's not a lot and it certainly doesn't look to want to come out.  I do not own the TP.
 
HS
 
Jan 7, 2015 at 7:18 PM Post #482 of 1,117
   
 
No...sorry.  To be clear the top plate on my WA7 has a bit of movement.  I thought it was the design.  It's not a lot and it certainly doesn't look to want to come out.  I do not own the TP.
 
HS


Thanks for letting me know. On my WA7 it's completely tight but the TP would move a bit. At least the silver colour is the same between the two units 
smily_headphones1.gif

 
I edited my previous message and it would be great if you could let me know if you've seen any sparks before on your tubes. Thanks HemiSam!
 
dL
 
Jan 7, 2015 at 8:13 PM Post #483 of 1,117
 
Thanks for letting me know. On my WA7 it's completely tight but the TP would move a bit. At least the silver colour is the same between the two units 
smily_headphones1.gif

 
I edited my previous message and it would be great if you could let me know if you've seen any sparks before on your tubes. Thanks HemiSam!
 
dL

 
No sparks on the tubes that I have ever seen and I've used mine quite a lot.
 
Happy to help.
 
HS
 
Jan 7, 2015 at 8:45 PM Post #484 of 1,117
I have seen arcing on mine once or twice using the Sylvanias but not the Mullers or the stock tubes.  I was worried at first too and was told this was normal for some types of tubes.  If it happens every time you turn it on and they are stock tubes I would ask Woo more about it.  I am guessing this arcing would lead to premature tube burnout if it happens often.
 
Jan 12, 2015 at 11:52 AM Post #485 of 1,117
A quick question to tube gurus...
 
I was looking for upgrading the tubes in my WA7tp unit and came across two options:
 
Ebay link and CanuckAudioMart link
 
The ebay one is quite a bit cheaper so I ordered a pair, but it appears that I missed the fact that the more expensive pair sold on CanuckAudioMart is actually a Gold brand with triple mica construction. I am told that the ones from eBay should prove much inferior with higher noise and lower life than the more expensive gold brand. Have I thrown out my money and will the pair I've bought from the eBay auction be completely useless (as in should I just stick with either the stock Sovtek tubes or get the Gold brand triple mica ones)?
 
I will be using the WA7/WA7tp with Audeze LCD-XC and Senn HD800 if that matters.
 
Any feedback and advice will be much appreciated.
 
Jan 12, 2015 at 1:06 PM Post #486 of 1,117
Hi Igor, 
 
I'm sure others more experienced with these tubes will weigh in soon, but to keep you going until that happens...   
 
I have also just begun to accumulate some tubes for my Wa7tp.  I haven't used mine yet  (i'm away for a couple of weeks) but wanted to get some different tubes to try when I'm home so have been looking and buying a few in anticipation.  So I can at least share my shopping & research experience.
 
As far as I can tell, the eBay link ones, which are the JAN ("Joint Army & Navy"  i.e. Military-spec) variety are exactly the type that have been used by many here with very positive results.  I got a few of those too since, as you say, they are pretty cheap and are said to give quite a full sound with a slight boost in bass.   The military-grade tubes are generally said to be more rugged so I wouldn't worry about their life expectancy, although with any tube you never know. 
 
When I was looking I also saw those other more expensive gold-pin "domestic" variety ones too I only read of one other person on this thread using those. They also posted favourable results but not necessarily different from the JANs.  They seem quite expensive so probably worth seeing how the JANs perform before paying the extra.  Perhaps someone has been able to compare the two, but I think the ones you got will be a good, inexpensive place to start - that's what I'm doing anyway!  
 
Just FYI, I also asked a few head-fiers for suggestions for tubes for Audeze headphones (mine is LCD-2F) and was heartily recommended the Mullard CV4003, another Military-spec tube made for the RAF, so I have a couple of those to try too.  They were about $40 a tube, so not cheap, but not crazy.   I just liked the idea of using something British in my otherwise all-American line-up!
 
 
My understanding is that since the WA7tp uses these 12au7 in rather a unique way - as rectifier tubes in a power-supply - conventional wisdom of how all these tubes are known to perform may well not apply in this case.   So,  if somebody who is using them in a different amplifier tells you one is "inferior" to the other it might be not be as relevant to use in the WA7tp.  The knowledge I'm drawing on is that of the early WA7tp tube-pioneers on this thread.
 
I'll post my impressions of all these tubes once I'm up and running and hope you do too, so we can get this thread rolling again! 
 
 
Jeb.
 
Jan 12, 2015 at 3:14 PM Post #487 of 1,117
Jeb, thanks so much for your thoughts and the info!  I feel somewhat reassured now that the JAN's I've purchased shouldn't be a waste.  I too thought of the fact that since these are to be used in a rectifier and not in the amp's signal path the rationale of them not being on par with the Gold brand triple mica ones may not apply.  Either way, it wasn't a huge amount so I won't start pulling my hair out just yet.
 
I read and re-read this thread and saw the mentions of the Mullard tubes, but so far the feedbacks haven't been quite as compelling as those on the Sylvania's.  This is my first tube amp experience and I want to make sure I follow the upgrade paths tried by the far more experienced members who are much better positioned to assess the pro's and con's and recommend the choices with the most bang for the buck.
 
To be honest, I am still using my WA7 with the stock Sovtek tubes (even though I have the EH upgrade tubes that Woo Audio sells on their site for $100) and the original solid state power supply.  I just felt that in order to appreciate the differences from tube rolling and using the tube power supply I should first acquaint myself with the sound signature of the stock barebones WA7 unit.  I must say it's pretty darn awesome even now, and if the EH tubes in the amp, as well as the tube power supply with Sylvania tubes are supposed to improve it even further, I plan on introducing the upgrades one by one so I actually hear and understand those differences.  A long (and somewhat masochistic) approach, but I thought I'd be more fun that way...
 
I love bass (controlled and precise, but impactful) and it looks like most of those who tried the Sylvania JAN tubes in the power supply units report deeper and punchier bass, as well as shaved off treble forwardness, which is just what the doctor ordered for HD800.  I am still unsure what kind of magic happens when different tubes are used in a rectifier which in theory just supplies the DC current, but if it works, I won't be complaining :)
 
Jan 12, 2015 at 4:33 PM Post #488 of 1,117

Igor - I love your approach of introducing just one variable at a time - it's one I intend to follow as well.  I think too much too quickly and it's hard to tell what is doing what. 
 
Bang for buck is a good way to go.  I've wondered if it's something of a "waste" to be using some of the finer NOS 12au7s as rectifiers - I guess it depends on the effect and the JANs would be a great way to test that.
 
For the WA7 Most have said stick the EH in right away, so I bought them at the time I got the amp too, but like you i'd like to get to know the stock Sovteks first - partly because, as I understand it,  those EH Gold Pins are no longer in production, so unless another manufacturer takes up the mantle. (which they might),  they will run out eventually.  Who knows how many Woo has - maybe enough for all of us for the foreseeable future.  I've also noted that not everyone prefers the EH, although most seem to. 
 
It's my first tube amp too so I'm really excited about trying the different combinations and having a slice of history in there to supply the magic! Since you are tuning the sound for the HD800 and me for the LCD2 we may well be wanting to do different things but it'd be great to hear how you get on.
 
One pair i'm looking forward to trying are these that I grabbed for a good price via Ebay: they are new production Psvane 12au7s, gold pins.  I thought it would be good to see how some of the new offerings fair.  I need to check compatibility - I think all 12au7s can be used but not sure if there is any variation in spec. 
 
Best of luck!
 
Jeb.
 
 
 
 
 
 
Jan 13, 2015 at 6:06 PM Post #491 of 1,117
  go for the NOS Mullards and never look back.

 
   
I'm using NOS Mullards as well and very happy with them.  I'm curious about the PSVANE though.


Could either please add some more specific info on the Mullards
When I hunt Mullard I find Mitcham , Blackburn , long plate , short plate , box plate , 10M , pinched waist etc
Many Thanks
 
Jan 15, 2015 at 9:05 PM Post #495 of 1,117
  Mullard NOS CV4003 Made In Great Britain, cryo treated sold by Upscale Audio.  I don't think you will ever find better.

 
Thanks for the post I'll be sure to check these out..
 

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