Pro Audio Design Forum

OK, I've been playing with this for a few days and the Hoshuyama topology is the way to go. Sam Hoshuyama was very kind to allow me to modify and use his SSM2164-based circuit. With the help of Gary Hebert of THAT to transform it to a non-inverting VCA, I was able to protoboard a 4 pole phaser. I'll...

This may be an earlier citation for an SSM2164 based phaser from Osamu Hoshuyama. It's dated before Neil's Webbly World phaser. http://userdisk.webry.biglobe.ne.jp/000/024/65/1/Vcph0505.GIF With some help from someone more skilled than I, I was able to modify the Hoshuyama circuit to use a THAT2180....

Yep, the Vos of an untrimmed 5534, though not a lot, at 6 mV/dB can provide significant tracking error in Ec.

Point taken on the Vos error. There will have to be a trim anyway to set the maximum gain limit to slightly less than unity. Right now the VCAs have a common Ec bus. If any of them go into gain, positive feedback results. I'm using a pre-bias of 3 mV, about -0.5dB, to keep that from happening. (The ...

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...