davemojo wrote: ↑Wed 03/17/21 3:37 am
There are at least 2 schematics soldering over the volume pots. I agree with you this can cause hum or ground looping can end to hum, but we have also another amp, build by another musician that followed a project such the one on photo and there is no hum or issues, so what is it really that is going to determine hum issues?
Soldering to the back of the pots and then using the pots to support a ground bus in this way is simply bad practice. It invites grounding problems. However, sometimes a designer who doesn't know better gets lucky, and his poor technique works satisfactorily with the particular layout he creates.
You have two choices: Wire it the way the pictorial shows and hope you also get lucky, or use a method that's more certain to work well. If you believe the original layout is repeatable in terms of performing well and that other builders have not experienced any issues, you might want to continue forward as-is. It's a judgement call.
Could anyone help on advising how I shall change that since it may imply quiet few changes now
My schematic guide is from stewmac but the mojotone are the same no difference, I believe tubedepot is also the same, so can we say that those companies are commercial and just dropping there a low quality build schematic?
If you decide to change it, you will need to remove all connections that are wired to the ground bus. You would need to instead connect all those points to a common terminal on the board, then run a wire from that terminal back to the ground at the supply capacitor. The capacitor on the Tone control can be wired directly to the Intensity pot, then a ground wire run from the two lugs of the Intensity pot to the common ground on the board.
Again, if you believe the existing design is repeatable and has proven to be trouble-free for other builders, you could continue to follow the existing layout. I don't have any personal experience with this build.
Jack