Peel;
All Marshall's have their own distinctive sound, partly because of their tone stack in the front end, but also partly because they keep a certain amount of crossover notch distortion in the output stage when they are properly adjusted.
The input is of high enough resistance that most pedals work quite well with these amps. I would play some with your bias, set it via the scope and crossover notch method rather than the current draw method on that particular amp, as you need to have the "Marshall notch" in there, but not too much ... not too little. A good Marshall guy can do this pretty easily.
Let he or she know at what settings you expect the play most often so it can be set for that particular area to be optimum, unlike the current draw method that is set at idle. Most amps like the current draw method just fine and dandy, Marshall's prefer a little different treatment to sound their best.
Keep the ECC83's in there if you want the Marshall sound, but try to find a very good one for V1 ... a NOS if you can spring for it. That is your tonal signature right there.
For V3, try to get a balanced (side A and side B of that tube should be less than .15 mA apart at 250 volts with a -2v bias). If you can get one at .1 mA or less, that is even better. Then make sure your output tubes are matched pretty closely.
If you want more clean headroom, I can help you with that, but then your Marshall won't sound as much as a Marshall.
Regards,
Myles Thx Myles - much appreciated, Ill take this to my amp tech when I get my new tubes. Any particular brand of tubes that might work with this amp better than others?
Peel
