But this time I went with a Merc Magnetics set of trannies - a 10 Henry choke, a 50W plexi O/T and a lower B+ 50W P/T. I'm getting right on 400VDC on the plates, which is significantly lower than any of my previous plexi builds. I wanted this amp to be easier to use at lower volumes, as a 50W plexi is so loud!
My use is probably very different from most of you here. I play jump blues and rockabilly with Gretsches, and these days prefer 1x12 combos because I am over lugging heavy amps to gigs. I have been using my own tweed amp-based designs for a few years now - mainly EL34 tweeds based on the 5F6-A or 5E7 circuits. I use beefed up P/Ts so I can run EL34s. Well this time it's all Marshall.
I don't have the cab yet, so I have been testing it through 1x12 tweed cabs with either a Celestion Gold or a G12H Creamback. Cranked it howls of course, but at lower volumes it really sounds beautiful. Warm, clear, punchy - like a tighter, clearer tweed. The low E string on my P90 Gibson 335 sounds like a piano string. Very happy! And I don't need any bright cap on the bright volume pot - it's plenty bright without it. It's a big, fat, warm, wonderful sound. I think the lower B+ and no bright cap lets me use it at a lower volume than my other 50W builds. The sound difference is subtler than I thought it might be, but I love it anyway.
) is the optimum voltage for a preamp valve to wirk at its best, we obsess about output valve plate voltage and bias assuming that when that is correct everyhting else downstream will automatically be correct too.
