Doepfer

Okay, a triangle wave from an LFO thru the A119 does indeed get 
inverted, but with a definite time lag. Suspecting a cap, I tried 
patching in the CV source instead. The DC was indeed blocked by the 
A119.

Although the A136 will indeed work as a voltage inverter, I forget to 
mention the hard clipping issue, which would affect LFO signals and 
Pitch CV among others (see my earlier posts on the subject). These 
would require an attenuator on the front end, compensated for by 
applying some gain to the output. The setup would require calibration 
if you needed exact -1 gain, but that wouldn't be important for most 
applications.

Joe

 --- In Doepfer_a100@y..., "mdimmm" <mdimmm@y...> wrote:
> --- In Doepfer_a100@y..., "buechlerjoe" <buechlerjoe@t...> 
> wrote:
> > > Are there any other modules besides the A-175 that do 
> voltage 
> > > inversion of CV? (A-119, A-116, A-136?). The A-119 doesn't 
> > > seem to handle CV signals very well, seems more suitable 
> for 
> > > inverting audio signals. 
> > 
> > The A136 works fine as a voltage inverter. The A116 might 
> possibly 
> > as well. My A119 doesn't have any voltage inversion 
> capabilities.
> 
> Actually, when I send a sawtooth signal to my software 
> oscilloscope, it shows up mirrored on the screen. When I patch 
> the signal through the A-119 (Asym. In) before sending it to the 
> computer, the waveform looks the way it does on the front of the 
> module. So it seems that the A-119 inverts audio signals. 
> 
> I believe the electronics involved in inverting a signal are 
> extremely simple (although I don't know what they are) which 
> makes me think it might be possible to fit the components into a 
> connector or something to be placed in between two patch 
> cables.
> 
> > 
> > > Since I don't have any space left in my rack, is there an easy 
> way 
> > > to construct a little outboard CV inverter? 
> > 
> > Mount an A175 in a little box with a wall wart, or the Doepfer 
> > mini-bus board/power supply.
> > 
> > Joe