Schematic editor with examples?

[glebert]

I've got a homebrewtique amp that I got from a friend who didn't keep track of what part values he used. It works but the tone isn't quite what I think it could be. The tonestack and resonance controls do almost nothing, the presence control only kicks in for about 1/4 of the sweep. I will need to go through and document part by part, but since it is based on a 1959 Super Lead it would be great to take an existing amp schematic file and modify it. Are there any free or cheap libraries of amp schematic files that can be used in a free or cheap schematic editor? For the rare times I do circuit sims I use LTSpice and have used easyeda.com for board layouts, but don't know that either of those platforms are going to be helpful.

TIA,
Greg

[glebert]

I found this page that has some LTspice files for some Fender amps. I downloaded the bassman schematic and will probably use that as starting point.

https://robrobinette.com/Tube_Amp_Spice_Analysis.htm