I am building a new CP103 this time based on a 1970-era "The Who" amp. There are a few detailed photos of what looks like genuine 1971 amps at Mark Huss' site, and the schematics are easily available. But I am trying to decipher one little detail about the B+ line.
The schematic shows a 22k dropper after the phase inverter supply, then another 10k between V3 and V1/V2. But in the amp photos, the 10k is connected directly to the 1k between the two sections of the 50+50 cap. So in other words, it looks like the 10k comes right after the phase inverter supply. Is the schematic wrong? I don't expect it to make much difference one way or the other, but I would like to try to make it as close to the original as possible.
https://hiwatt.org/pix.php?p=pCP103_2Gfs
CP103 circuit details question
Moderator: Mods
Re: CP103 circuit details question
I can't really tell either. As you say, it probably won't make any difference.
Re: CP103 circuit details question
Thanks for your reply, Mark. I am building it with a 10 k between the PI and V3, then a 22k between the two sections of the preamp filter cap so V1,V2 and V4 are fed from the far side of that resistor. Seems the most likely way it's done judging by the photos.