SLO100 parallel channels

[lowell]

This amp rocks, but I'm boggled as to how the signals, when combined together at VR2, look as though out of phase. Is this schem accurate? It seems clear to me that the clean channel goes through 2 tubes (in phase with input signal at VR2) and the OD channel goes through 3 tubes (out of phase with input signal at VR2).

[Alex R]

Is it not an either/or switching situation?

[lowell]

no the clean channel is always on up till the master volume, the OD switch just adds the 2 tubes of the OD into the clean signal.

[tubeswell]

Yep that's right, the clean is always on - it just gets drowned out by all the raucous sound when the OD kicks in. Kinda like cross talk that doesn't matter, and just adds another dimension to the sound

[Joss]

Yes, the schem is accurate.

[defaced]

The guys at the SLOClone forum have added a fifth LDR to decrease bleed from the clean channel into the OD channel. It's placed between the 120p||2.2M and the 330k/VR2/220k node.

[lowell]

seems as though there'd be enough signal to cause a cancellation issue, affecting the OD tone/volume. I have an amp of my own design that is quite similar in the OD, however my OD has 4 total OD stages, I'm gonna give it a go w/ the clean channel on in parallel w/ the OD channel and see if I dig it, since both channels are in phase. My OD doesn't sound right unless the master volume is at least half way up, and that's too loud! I feel as though keeping the clean channel in parallel will keep that fatness of tone and the OD will add the crunch and bite. i'll report back if I like it or not.

[Alex R]

Maybe it's done deliberately to add a bit of nfb to control things a wee bit.