Pro Audio Design Forum

I took a little break from working at the O.K. Ranch to test out a few phaser ideas. With brush set-out about another week away the chainsaw and I are enjoying a little separation. I do miss the smell of 2 cycle fuel though. Bifet op amps for the VCA input buffer and the all-pass sections is a defin...

Probably want to settle on 0-5V and +/-5V sweep inputs then. Makes envelope control easy. Could have a single input with bypassable level shifter to switch between unipolar and bipolar sweep. Exactly my thought Roger. Thanks emrr for the feedback on the samples. I was concerned that phasing may hav...

I was thinking about keyed effects based on dynamics and some crude form of frequency tracking in addition to an LFO. I'd like it to mutate a high hat by being keyed from it or follow a guitar part kinda-sorta. (Which I did by knob turning.) Pedal operation for sure. Stuff that made the DynaFlanger ...

yes gain cell is non inverting, looks like voltage input, not current input. I think it's current in. http://www.analog.com/static/imported-files/data_sheets/SSM2164.pdf The 30K is the input V-I converter. The 30K wrapped around from the output back to the 2164 input alters the gain control slope (...

That's a good question. I think I would include in that design the use of digi-pots for some things (e.g. makeup gain, threshold etc in the dynamics) where you're potentiometrically controlling DC. For the preamps and line inputs a 1570/5171 combo might be included since VCAs wouldn't lend themselve...

John: I found another cite for an SSM2164-based phaser and it looks like the Cfb around the I-V converter were made bigger so that it acts more like a voltage variable integrator: http://userdisk.webry.biglobe.ne.jp/000/024/65/1/Vcph0505.GIF From looking at the all-pass network, doesn't it look like...

Here's a demo of the 8 pole with the last tap summed with direct. This one is mono output. http://www.proaudiodesignforum.com/content/VCA_Based_8_Pole_Phaser_Demo_8th_Tap_Only.mp3 (~1.5 MB) This following sample is with both the 4th and 8th sections summed with the direct. It's a little thinner but ...

No complication for the 12 pole - just running out of VCAs and protoboard room. I think this thing could be cascaded in three blocks of four to do a 12 pole. I'm not sure if the SSM2164 inverts or not. It looks like a voltage variable integrator with local feedback taken into the input summing node....

I think for now I'll align them using equal C values. That's how I usually see them. The Ec will be bused and they ought to track well. I may experiment with having an inverted CV to four of the (eight) poles so that as one goes up the other sweeps down. I also need to revisit Thomas Henry's Barber ...

Should I continue with this?