Voltage Controlled Crossfader/VCA

[ReToxx]

Thank U!
But here is another question: if I want to use it internally, as in my example, where the inputs are hardwired to both, the inverted and noninverted output of my filter, could I get rid of the two unity gain amps just before LM13700? And maybe I don't need the two ac coupling capacitors? Shouldn't it be possible to take the direct signals straight into the lm13700s?

[fonik]

[fonik]

With the kind permission of Mr Thomas Henry i will offer PCBs and front panels for the VC Crossfader/VCA soon. The prototype PCBs arived just today:


VCXFaderVCA by Matthias Herrmann, on Flickr

[fonik]

okay, i decided to do a 12HP version, offering attenuators for all inputs and the AC/DC switches. believe me, you really want all those attenuators!


TH VC FaderVCA by Matthias Herrmann, on Flickr

[fonik]

and this is how the finished module will look like:


TH-VC-Fader by Matthias Herrmann, on Flickr

[nhouse]

[elmegil]

It is a Eurorack module, whose system power is already +/- 12V.

Is that what you're asking, where the 12V comes from?

[nhouse]

nope, i'm aware of that.
i posted a url with fonik vca's schematic and i read that at the beginning (from the header)the voltage is +-15V and after some the caps it becomes +-12V.
actually pin 1-2 of the Eurorack header should provide the -12V and the 9-10 the +12V .
it just confuses me

[elmegil]

I suspect it's an oversight in revising the schematic, since the original was 15V.

[nhouse]

ok .this is what i think too. but i needed to double check!=)