I've recently started having success with building preamps. First started out with a cathode follower as a reamp box, then a vox AC30 and so on...
Now I think i'm ready for a power amp, and I've designed it myself.
Here is the schematic: DIY amp - Album on Imgur
Do you guys see any problems/have any remarks?
Much appreciated!
Now I think i'm ready for a power amp, and I've designed it myself.
Here is the schematic: DIY amp - Album on Imgur
Do you guys see any problems/have any remarks?
Much appreciated!
R13 is the wrong value. Should read 1k. I would fit a 22nF capacitor as a DC stopper on the volume control, just in case. Looks like a Marshall pre amp stage and standard output stage. Should work OK.
Thanks for the quick response!
Here's the corrected schematic : http://imgur.com/a/pmWZi
Here's the corrected schematic : http://imgur.com/a/pmWZi
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You will need some filtering of the DC-supply voltage of the pre-amplifies triodes to reduce hum.
I don't build SE amps but the data sheet says max value of R10 is 500k. Fender 5E1,5F1 Champ use only 220k. See bottom of page 1, Class A1 amp, with cathode bias: http://www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6V6GT.pdf
1) move volume control between first and second triode, otherwise you will have annoying hiss and hum even with volume on 0.
2) besides, 100k is quite a low load value for a standard guitar pickup, specially if a humbucker, most are happy with 1M
Which is what you´ll have if you move volume control elsewhere.
3) you are using the 6V6 as a triode, which lowers power and makes it bland sounding, a pentode has way more bite.
Add the proper supply to the screen.
2) besides, 100k is quite a low load value for a standard guitar pickup, specially if a humbucker, most are happy with 1M
Which is what you´ll have if you move volume control elsewhere.
3) you are using the 6V6 as a triode, which lowers power and makes it bland sounding, a pentode has way more bite.
Add the proper supply to the screen.
Hasn't the perfect 12AX7/6V6 guitar amp already been found? Fender AA Champ?
At least look at it and defend why you do it different.
As said, Vol pot in front degrades S/N, 100K input damps string-zing, and historically guitarists have found triode power "too polite" to cut through a crowd. All of these points depend on your taste. If you are all-pedals, the input impedance may not matter, and your HornyFrog fuzz may cut-through the politeness. But Champs and Champ-copies still sell in the millions. This IS a reason to do-different. But be sure you are not headed for disappointment.
The tip about preamp filtering MUST be addressed. You generally can not put 3 stages on one power filter. You generally want preamp power much-much cleaner than you can afford to make power-stage supply. If you go pentode-power you want screen supply somewhat cleaner than the big plate power.
At least look at it and defend why you do it different.
As said, Vol pot in front degrades S/N, 100K input damps string-zing, and historically guitarists have found triode power "too polite" to cut through a crowd. All of these points depend on your taste. If you are all-pedals, the input impedance may not matter, and your HornyFrog fuzz may cut-through the politeness. But Champs and Champ-copies still sell in the millions. This IS a reason to do-different. But be sure you are not headed for disappointment.
The tip about preamp filtering MUST be addressed. You generally can not put 3 stages on one power filter. You generally want preamp power much-much cleaner than you can afford to make power-stage supply. If you go pentode-power you want screen supply somewhat cleaner than the big plate power.
Dear lingwendil, I suggest you open a new thread specially for your doubt, and can have dedicated answers, instead of deviating mk5studios´ thread.
🙂
🙂
I will, I just figured it would be a good place to ask, that way we can compare to the OP's design. Would be good to see more of what PRR is talking about, so we can see what to do. Copying older existing designs is fun and all, but I wanted to see what's going on with the design the op posted in comparison.
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