[sdiy] Scanner Chorus pcb interest?

[JH.]

 Thinking about future pcb projects ...

One thing I wanted to do for a long time is a stereo chorus based on my 
electronic emulation of the Hammond Scanner Vibrato.

I've built something like that a few years ago:

http://jhaible.heim.at/scanner_vibrato/jh_scanner_vibrato.html

This was purely intended to be an emulation of the Hammond Chorus/Vibrato 
effect, but I always thought it would also make an interesting, more 
general, and stereo, chorus device.

That would be a "true analogue" chorus in a different sense than the 
BBD-based effects, because the signal is not sampled.

It's not free of side effects, thou. It has a somewhat rough modulation 
waveform, as instead of changing a delay time continuously, it interpolates 
between 9 taps of a 1ms analogue delay line. It's a linear interpolation, 
not a switching - best thing is you listen to the sound samples and decide 
for yourself. It's very rough (in a Hammond-ish way!) for vibrato, and 
increasingly smoother when the dry signal is mixed in for chorus.

It's a quite complicated method to crate a simple chorus, compared to a BBD 
circuit. It requires a 50-pole (fifty!) low pass filter, but that can easily 
be built from 25 cheap inductors (less than a dollar per piece at Mouser) 
and 25 capacitors.

On the positive side, it's a lot more "direct" sounding than a BBD-based (or 
digital delay based) chorus, as the maximum delay time thru the whole 
circuit is only 1ms. (Speak of latency ...)

If there's enough interest, this could be a project for a future PCB 
development. I wouldn't restrict this to Hammond emulation, but make a 
mono-in / stereo out device in the fashion of many Roland / Boss dual-BBD 
chorus circuits. Just without BBD. Let me know what you think ...

JH.

PS: this is not to be confused with my Interpolating Scanner, which is 
planned to be a future MOTM module.