Right, that's what I'll be looking for. Here's the schematic I'm working from.bassdriver wrote: Wed Jun 25, 2025 11:11 amYou can measure ac of the transformer before the diodes. I think a center tapped 2x18 VAC transformer will get you the desired 22V dc. Then you should be reading -/+ 22V dc at those huge 2200 uF caps once on the positive side of the cap and for the negative voltage on the - side of the other cap.VaticanShotglass wrote: Tue Jun 24, 2025 4:31 pm Transferring this from the Small Questions thread here and here.
I spent the weekend in beautiful expensive Carboro and saw the Godspeed You Black Emperor show, but before leaving I was able to pop open the little TS-10 I got last week. I printed out a schematic and got familiar with the circuitboard. According to the schematic, the circuit wants to see +/- 22 V. Unfortunately, I need to track down my nice multimeter, so I'll have to get back at it this Sunday.
I couldn't find any info on the Peavey transformer, nor did it have any clear values marked on the housing.
I did yank out the trash speaker and popped in this little EHX 4 Ohm speaker that has been poorly stored in closets and a dank garage for 15 years. I rolled the dice and fired it up. Immediately, it sounded much better. Still had a kinda noise going on when you played the bass strings. It's hard to describe, a kind of distortion going on behind the circuit's overdrive. It is also still very bright even with my dark Les Paul and the tone rolled back 10 o'clock. Hard to say if these issues are due to
1. this just being a trashy little solid state practice amp,
2. the EHX speaker acquiring problems over the years (it never had any noise issues nor was it particularly bright when it came in my champ), or
3. there's still funkiness going on from mods by a previous owner.
Pictures here: https://imgur.com/a/0ydvfBC
Let's say it does read -/+ 22V. What sort of speaker would the amp be looking for? I assume it would be the same as the original if all the measurements are to spec, but I can't find any info on the original speakers.
Also, are there any other spots I should check while I'm in there? The old transformer got replaced for some reason, may as well look for problems that might have caused it to fail before. Someone did add an external speaker jack parallel (I think) to the normal speaker line. I haven't messed with that at all.