Re: Tube lineup
I use TAD el84s and SED Winged C 6L6's
Preamp tubes a mixture of Tungsol, Penta labs and JJ.
I had all sorts of trouble with Tungsol pre's with my GH50l in V1 and V2. Just gave a loud humming.
Penta Labs are a great chinese tube for gain. JJ are a darker tube. I do not like these at all in the first couple of slots Tungsols are clear and punchy, great tube but due to the long plate seem to be prone to noise in some amps.
Every amp responds differently to tube change. The best thing about pre's is that unless you go NOS they are cheap. I've got shit loads and it took me a long time to work out what worked and what didn't. Even using the same tubes in different slots made a big difference.