My tube set up as follows:

Mullard 5y3GT
Russian military 6n15n-EB
Mullard 12au7 (1950's)

[quote author=msa  link=1140475196/0#2 date=1140488295]Is that Russian tube the same as their military EL84 that gets a lot of good press?

I didn't have a good 12au7 to try, but an RCA 5814A, which sounded great in another amp, didn't quite make the grade "hear".

Fun, isn't it? [/quote]

The military EL84 is 6n14n-EB, the SV-83 is 6n15n-EB. I have not tried the EL84 in my amp. I find EL84 a bit forward in Taboo.

The advantage of using 12au7 is I can crank my CSP volume all the way up without any distortion.

It can be used.

You should try the military SV83 then. You may be surprised  ;D

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5875459900&rd=1&sspagename=ST...

They will sound much better as they break in. But difference will be in that they will be more laid back than the EL 84. I am glad you like them. Here is what Steve says in his design note for Taboo

In the Taboo, the SV83's used in our Triode amps sound very good.  Glass smooth with great micro detail.  A good pair of EL84's have more spank and presence.  The difference between the two is fairly large while on the Triode amps the difference is only nominal.