The CEM3381/PA381 VCAs have current outputs (not voltage outputs as usual). The currents of the four CEM3381/PA381 are summed up in a current-to-voltage converter to obtain a common voltage output. This is why you do not obtain an signal at the CEM3381/PA381 (current) outputs. One would require a separate current-to-voltage converter for each section of the CEM3381/PA381 VCAs followed by a (voltage) summing unit. But this would require a lot of modifications of the A-135 module. Best wishes Dieter Doepfer > I basically want to be able to make seperate outputs for each channel > after the cv attenuator circuitry. I am having trouble figuring out > exactly how the circuit works - I was thinking that the final stage > before each channel's signal get summed and then led through the > makeup gain ic and then to the master out - is on the pa 381 ic. So my > plan was to just tap the seperate outputs from the two pa381 ic's and > then lead each channel into it's own seperate makeup gain opamp,,,, > > So I tried this but wasn't getting any signal.... I'm sure if I could > see the schematics I could make better sense of everything,,,, anyhow > I am hoping somoene can offer some insight on how to actually do this. > > It would be great to have the seperate outs,,, would be like have an > extra 4 vca's available! > > Thank You! > > > > > > > > Yahoo! Groups Links > > > > > >
Message
AW: [Doepfer_a100] modifying the a-135 quad mixer module
2005-11-21 by Dieter Doepfer
Attachments
- No local attachments were found for this message.