[chrisld]

I have had the WA2 for a couple of months now and it's been a journey to get great sound. Without question, the device is excellent (mine has the Black Gate caps and stepped attenuator) but you need the right tubes to get a great sound.
What is great sound? Well, for me it's sound that is musically enjoyable with natural sounding harmonics and no harshness. It's hard to get that without losing detail and requires careful experimentation. I can't tell you what you will like but I'd like to share what I believe to be a great set-up.

First I'd like to say that changing any one of the three tube types (rectifier, power tube or output tube) can change the sound from great to bad. It's really that sensitive. That also means you may not want to blow $200 or $400 on some NOS output tubes only to find you're too broke to buy the rectifier and power tubes you need to get the sound you want.

I have bought a lot of tubes and each time only changed one type, taking notes on the sound, then changing again. I will not detail every combination and my notes but here is a list of tubes I have tried so far. The good news is that there is virtually no correlation between price or new versus NOS and sound quality. This gives you the chance to get a great set-up without breaking the bank.
My original goal was to get the cheapest set-up that sounded really good and to do it using only current production tubes because that would mean I could always get the tubes I needed to have great sound. NOS tubes cost more and there's no guarantee you'll still be able to find your favorites ones a few years from now. At the end I will recommend the cheapest set-up that sounds satisfying (to me) and then the best set-up so far irrespective of price. Note however, that I have not yet tried the super expensive output NOS tubes out there.

Test set-up is a PC, ASUS Xonar STX Sound card, Harmonic Technology TruthLink II interconnects, Woo Audio 2 and Beyer Dynamic T1 headphones.
 
These are rated from best to worst. All tubes bought from www.thetubedepot.com and www.thetubestore.com apart from Tung Sols from Ebay.


Rectifier:

Tesla 6CA4 / EZ81 $20 each (these top three all sound great)
Electro Harmonix 6CA4  $14 each
JJ EZ81 / 6CA4 $12 each
Mullard 6V4 NOS matched pair Woo upgrade $70 each (lack dynamics, boringly smooth)


Power Tube:

Tung Sol 5998 NOS Best $115 each Magical combination of control, harmonic richness and transparency
Tung Sol 7236 NOS $125 each (not nearly as good as the Tung Sol 5998)
Sylvania 7236 NOS $60 each (Woo upgrade) adds punch and control compared to the Sovtek
Sovtek 6AS7G $50 each adds richness compared to the Sino
Sino 6AS7 $14 each surprisingly satisfying for the price
RCA 6080 NOS (stock Woo) sounds like a thick veil stands between you and the music
 

Output Tube:

JAN-Sylvania 7308 NOS Best $60 each
JJ E88CC / 6922 Gold (great value) $25 each

Philips 7DJ8 / PCC88 NOS $20 each

Not musically enjoyable / harsh

Genalex - Gold Lion E88CC / 6922 $45 each
Tesla E88CC / 6922 Steel Pin $25 each
Hand-pick matched pair Philips 6922 JAN Woo upgrade $20 each

For the rectifier tubes, you can get great performance for low expenditure. NOS tubes may be a waste of money.

For the power tubes they don't seem to make the sound good or bad but rather change the degree of control, dynamics and richness. The Tung Sol 5998 are king and make a huge difference. For me, you have to have those or you are not getting the most from your WA2. They give such control with transparency and great, natural harmonics. They just sound so "right".

There are a huge number of options for output tubes. The JJ were my favorites and are satisfying, not to mention inexpensive. A great buy. Then I tried the Sylvania 7308 and they are as close to perfect as I can imagine without having heard the more expensive options.
 
Least Expensive Good Sounding Combination
JJ EZ81 / 6CA4 $12 each,  Sino 6AS7 $14 each, JJ E88CC / 6922 Gold $25 each
 
Best Sounding Combination
Tesla 6CA4 / EZ81 $20 each, Tung Sol 5998 NOS Best $115 each, JAN-Sylvania 7308 NOS Best $60 each


I spent quite a bit of time and money looking for that magical combination and I hope someone else can spend a little less of each on their journey having read this. If you do by a WA2 then you really need to change the tubes to get good sound.

 

[Draygonn]

Great info chrisld. I recently bought a WA2 off Sophonax and I'm running Telefunken EZ80s and Mullard CV2492s and just ordered TS5998's off eBay. I'm a novice tube roller so I'm duplicating the setup MacedonianHero used (first owner of my WA2).

 

[chrisld]

From what I've read of those tubes you'll be delighted as soon as you have the 5998 tubes installed!! Looking forward to your impressions.

 

[Aethelred]

Just a hint of warning, 5998 are rather on the lean side of the sound. If anybody is looking for richness in sound 6as7 are hard to beat+e88cc red VALVO from Heerlen and ez80 from RTF. This is my all time favourite combination.

 

[chrisld]

Bought some new power tubes.
 
RCA 6AS7G - Sound enjoyable
 
GE 6AS7G - Did not enjoy these
 
GE 5998A - Liked these quite a lot but not as much as Tung Sol 5998
 
Weirdly the GE 5998A (says that on the tubes and on the original boxes) has an identical plate formation with subtle differences inside the tube at the top. The 5998 boxes are shorter than the 6AS7G but the tubes are slightly taller.
 
Waiting for Skylab to chime in.

 

[MacedonianHero]

Quote:

Great info chrisld. I recently bought a WA2 off Sophonax and I'm running Telefunken EZ80s and Mullard CV2492s and just ordered TS5998's off eBay. I'm a novice tube roller so I'm duplicating the setup MacedonianHero used (first owner of my WA2).

Yep...those were my favourite WA2 tubes:

TS5998 Power Tubes
CV2492 Mullard Driver Tubes
EZ80 Telefunken or Mullard Rectfifier tubes
 
Simply one fantastic sounding amp with those tubes! I hope you enjoy it as much as I did.
 

 

[chrisld]

I uploaded a picture of the GE 5998A (left) next to the GE 6AS7G (right). You can't see it in that shot but the alleged 5998A does say that on the glass too.
 
As mentioned the one labeled 5998A is a longer tube but comes in a shorter box.
 
http://hotfile.com/dl/133041437/42c1ae9/TubesWeb.jpg.html
 
All the best,
 
Chris

 

[MacedonianHero]

Quote:

I uploaded a picture of the GE 5998A (left) next to the GE 6AS7G (right). You can't see it in that shot but the alleged 5998A does say that on the glass too.
 
As mentioned the one labeled 5998A is a longer tube but comes in a shorter box.
 
http://hotfile.com/dl/133041437/42c1ae9/TubesWeb.jpg.html
 
All the best,
 
Chris

FYI...the 5998A is a different tube than the 5998. The 5998 is a great tube and the 5998A is mediocre at best.
 

 

[chrisld]

That's pretty much in line with what I found. The 5998 Tung Sol is my clear favorite. Was intrigued that GE made something called a 5998A which has identical plates to their own 6AS7G but in a different glass envelope. Do the two have different specs?

 

[owidjaja]

Have any body Used E188CC Seimens for their output tube?

 

[oldwine]

No, but i now uses the Siemens E288CC. It sounds more open and airy compared to my Amperex 7308.

 

[Dubstep Girl]

RCA 6AS7 are really nice. not as good as sylvania 7236, but they are warmer and smoother sounding. probably one of the better options for power tubes if you don't feel like spending alot of money.

 

[DWolff]

Hey all,

First post on this forum.
Have a WA2 with DACT attenuator on the way and I've spent a fair bit of time tracking down a paired 5998/7308/EZ80 setup. This is my first foray into tubes and the info on this forum has been most helpful and appreciated. This will be driving a pair of T1s and, based on all accounts here, my expectations are high!

I wondered what kind of lifespan you are getting from these tubes in the WA2. Seems to me that the sought-after NOS tubes will only get more $$ over time. How often are you replacing them?

Thanks in advance. Apologies in advance for any and all grotesquely naive questions.

All the best

 

[Dubstep Girl]

Quote:

Hey all,

First post on this forum.
Have a WA2 with DACT attenuator on the way and I've spent a fair bit of time tracking down a paired 5998/7308/EZ80 setup. This is my first foray into tubes and the info on this forum has been most helpful and appreciated. This will be driving a pair of T1s and, based on all accounts here, my expectations are high!

I wondered what kind of lifespan you are getting from these tubes in the WA2. Seems to me that the sought-after NOS tubes will only get more $$ over time. How often are you replacing them?

Thanks in advance. Apologies in advance for any and all grotesquely naive questions.

All the best

 
 
i've had my amp for over a year now and the tubes are still going strong. 
 
i believe its expected for 7308/6922 tubes to have around 10,000 hours, the rectifiers should be around the same, and the powers are 5000-9000ish? 
 
some people have tubes die prematurely, while others use them for years and years without any issues. so it varies on alot of factors, including brand, tube type, amp, and usage

 

[DWolff]

Thanks very much for sharing your experience.

By my math that works out to ~5 years with 2-3 hours of daily use. Sounds good to me. Don't know if this is truly justified, but I'm a bit afraid of what replacement TS 5998s will cost 5 years from now.