[GrindingThud]

For those wondering if 6SN7 to 6CG7 adapters work well in the WA3, they do! 6SN7GT mouse ears are quiet, detailed, and throw an outstanding soundstage with the 5998/421A type tube.

Adapters off eBay from here: http://www.ebay.com/itm/221065459067?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648
Beware...the pins are a tad long, so don't push them in hard or bottom them out.
I tried to get adapters from Woo but the demand was too low for them to do a 1 off adapter with this pinout. If enough demand pops up and they do a run of these, I'd be in for a pair.

...Update on the sound: Simply outstanding! The mouse ear 6SN7GT sounds effortless driving the 421A. The soundstage is super deep and the mids and highs very detailed. The sub bass is not as pronounced as with the A frames, but the feeling of space feels somehow more realistic.
...trade is that you end up with less drive into the power tube, but I don't play anything that loud that I notice.

 

[GrindingThud]

So, I finally squeezed in the stealth diodes.....been raining for a week and needed to break out the soldering iron.
Not exactly the install I was imagining, but they did fit in the existing holes without much trouble. I did have to bend them down some to keep the backs from shorting.
They do sound good though.
....really good. If I had to describe the change, it would be improved 'coherency', or stronger imaging that hides the presence of the headphones.
Fairchild ISL9R860P2 Stealth™

.....forgot to mention I bought a quad of stealth diodes to replace the bridge. Plan was to put them on a daughter board and mount to the PS board, but the new caps were rather largish and ate my planned space. Diodes are on hold until I can figure out a clean install.

 

[Bothand Nether]

For those wondering if 6SN7 to 6CG7 adapters work well in the WA3, they do! 6SN7GT mouse ears are quiet, detailed, and throw an outstanding soundstage with the 5998/421A type tube.

Adapters off eBay from here: http://www.ebay.com/itm/221065459067?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648
Beware...the pins are a tad long, so don't push them in hard or bottom them out.
I tried to get adapters from Woo but the demand was too low for them to do a 1 off adapter with this pinout. If enough demand pops up and they do a run of these, I'd be in for a pair.

...Update on the sound: Simply outstanding! The mouse ear 6SN7GT sounds effortless driving the 421A. The soundstage is super deep and the mids and highs very detailed. The sub bass is not as pronounced as with the A frames, but the feeling of space feels somehow more realistic.
...trade is that you end up with less drive into the power tube, but I don't play anything that loud that I notice.

Having received a court order to exhume this thread.......
 
I just wanted to say I actually squealed when I saw this,
as I have been eyeing these adapters....Great tip on the pin length, forewarned is forearmed!
 
Thank You (and all You guys) for all of this great info!
I have some RCA 5691 tubes I will have to dig up.
 
Now if I slap a 6sn7 to 12AU7 adapter into that adapter, Could I run My GB 5751s ?..........

 
I will post a shot of My Gen 1 WA3 when it arrives, thanx alot folx 

Now look what You've done.

 

 

[Bothand Nether]

Couldn't find them in My RCA Box, They were rebranded GE 5691s. 

Below is a the 5691 envelope next to a GE 6SN7.
The RCA 5691 tubes were over -engineered for Avionics & have a 10k lifespan & are very quiet in My old Fender Champion.

I may Have another Pair in My Tung-Sol Box, I will keep digging while I wait for My WA3
I have a matched Quad of the GE 6SN7 tubes, & at least 1 matched set of 5691s.
 
There are several incarnations, the supposedly "best" ones were old-style logo RCA JAN-CRC 5691
with Red Lettering & deep black plates, as I recall.
 
FWIW,The 5692 is the 6SL7 version, & is to the 6SN7 like a 12AX7 to a 12AU7. 

 

[Gethyn]

Hello Everyone,

I hope that resurrecting this thread is ok! I have read it from start to finish and am so grateful for the advice. Unfortunately tube rolling is new to me so I am still a little confused, specifically about what tubes or types of tube will fit the amp.

I have just bought a WA3 and one of the tubes doesn't work so I am obviously keen to find a replacement asap. I live in Hong Kong and know of an amazing looking shop selling tubes - there are hundreds and hundreds of them. I don't really know what to ask for when I go there though and with a likely language barrier I am going to struggle even more. Is there a generic number or code or something for the correct fitting tubes that I can ask for? I am getting confused by all of the different tube manufacturers and numbers that people have recommended so can anyone simplify things for me?

Many thanks!

Gethyn

P.S. My headphones are Sennheiser HD800s and Audeze LCD2s so if anyone also has rcommendations for which tubes might best pair with either of these headphones I'd be really grateful. Thanks again!

 

[Gethyn]

Well I took the plunge and followed some of the excellent advice on this thread. I bought a pair of Amperex drive tubes and a Tung Sol 5998 and am delighted by the result. I am using HD800s with the WA3 and they were excellent before, but the replacement tubes have added greater clarity and detail to the sound. I wasn't too keen on the HD800s with a solid state amp; the detail and soundstage were amazing, but they were also a little fatiguing and certainly not especially enjoyable. With the WA3 and its new tubes the sound is fabulous and much more enjoyable to listen to without losing the amazing detail that the 800s provide.

I'm very happy indeed and grateful to everyone who has posted on this thread - thanks!

 

[Glow Fish]

The Woo website has a list of compatible tubes.

 

[jamato8]

This is an old thread. Glad people still find it useful from time to time. 

 

[GrindingThud]

One of my favorites!