Thomas White 292c question

[RSFC]

I’m working on my panel layout for my Thomas White 292c. Looking at his MOTM panel designs I don’t really understand the CV and CTRL differentiation. Both the single panel and double panel have distinct separate jacks for “CV” and “control”. All I can guess is that they are both just CV inputs and one has attenuation and the other doesn’t. I just want to make sure I am not missing something.

[emdot_ambient]

That's exactly what it is.

If you look at the PCB you'll see there are 2 sections that have "IN1", "IN2" and "IN3" pads along the edge. One of those is marked "CV SUM STAGE". To the right of that, though, there is also one pad marked "CV" under the title "DIRECT INS".

The only difference between them is tha the "CV SUM STAGE" inputs are all mixed together and can have attenuators added (or not). Those don't have to be used and can actually be used as a seperate 3-input mixer if you need it. The "DIRECT INS" section are unattenuated straight inputs, one for Audio and one for CV.

I'm pretty sure the jack on the MOTM panels marked CTRL is wired to the "DIRECT INS" CV input, while the CV input(s) are going to the CV mixer and are attenuated.

[emdot_ambient]

Actually, if you look at the schematic, you'll see the Direct CV Input in the dop left, going to Pin 1 of the CV Jumper. Pin 2 connects to the CV Sum Stage (kind of in the middle of the schematic) with its 3 inputs.

You could, of course, add attenuation on the Direct CV In...but it isn't run through the CV Sum section.

[RSFC]

Thanks. I am trying to design a panel similar to the original but also incorporate some of the additional features. So CV attenuation may be out…

[diablojoy]

[fonik]

well put, diablojoy. actually i want this for any VCF.

[RSFC]

The LPGs were originally designed to be used at lower levels (buchla was/is line level, no?) than what is the norm in DIY land. Thoughts?

[knob_alchemist]

Anybody can help me with this trouble?