I've just bought marshall jmp-1 preamp. I dont have enough money to boy appropiate power amp, so i decided to ask my friend to build it for me (he has a lot of expirience in electronics).
I searched for schematics and i think maybe this one will do the job:
2x20w - enough for me i hope
The questios are:
1) Will this power amp be a good match for marshall jmp-1 preamp ?
2) how much will this cost (parts w/out case, just electronic components)
3) Is 2x20W in stereo ienough for club gigs??
thanks!!
I searched for schematics and i think maybe this one will do the job:
An externally hosted image should be here but it was not working when we last tested it.
2x20w - enough for me i hope
The questios are:
1) Will this power amp be a good match for marshall jmp-1 preamp ?
2) how much will this cost (parts w/out case, just electronic components)
3) Is 2x20W in stereo ienough for club gigs??
thanks!!
As for your question, I don't know how they manged to get away with that, but the amplifier shown will dissipate 20W (actually more like 25-30W) in the EL34, as burned heat; what it will never do is output 20W. At best, 8W, and more likely, 3 to 5W.
From a hi-fi standpoint, the power amp circuit is okay, although you might want a small capacitor across the 22k running from the output secondary; depends on the OPT. For guitar, I've heard many people prefer it without the 22k entirely (no negative feedback). It should be softer and crunchier, not to mention have more gain.
From what I hear, 20W may or may not be enough. Depends on the stage, room and speaker(s). Certainly, you'll need a push-pull amplifier using EL34, EL84, 6V6 or 6L6 (or any equivalent like 5881), to name a few. Those will give between 10 and 50W, up to 100 or 200W if you use a paralleled design. If you're moving this a lot by hand, you might want to know the output and power transformers get weighty above 30W...
Tim
From a hi-fi standpoint, the power amp circuit is okay, although you might want a small capacitor across the 22k running from the output secondary; depends on the OPT. For guitar, I've heard many people prefer it without the 22k entirely (no negative feedback). It should be softer and crunchier, not to mention have more gain.
From what I hear, 20W may or may not be enough. Depends on the stage, room and speaker(s). Certainly, you'll need a push-pull amplifier using EL34, EL84, 6V6 or 6L6 (or any equivalent like 5881), to name a few. Those will give between 10 and 50W, up to 100 or 200W if you use a paralleled design. If you're moving this a lot by hand, you might want to know the output and power transformers get weighty above 30W...
Tim
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