Ahhh... I've read about that. Laney wire there power tubes up differently which stops you using some NOS vintage tubes. So you're now free to use Mullards! If your interested here's some blurb:
"Laney uses pin 1 on it's VC30 as a tie point for the screen resistor and the 290V supply. Ei uses a variant pinout in their EL84 common to some of the vintage 6BQ5's (GE, others) where pin 1 is tied internally to pin 2. Note that Sovtek, which comes standard in the Laney, does not use pin 1 and strictly follows the "standard" pinout. This means that Ei and many NOS EL84/6BQ5's will not work in a Laney unless it's modified. Fortunately the Laney uses point to point wiring for it's tube sockets and the change is simple. Just use pin 8 (which is unused in the Laney and is a "no connection" on most EL84's) as the tie point instead of pin 1. The amp will now work with either Sovtek, Ei, or most NOS tubes."
The reason I asked is that I heard you can modify the effects loop to act as a Master Volume. My VC30 sounds fantastic cranked, but she is one very loud beast!
Cheers
BM