via JH on AH:"many of you have shown interest in my PCB project to emulate the string ensemble effect of Solina, Crumar, and other similar keyboards. I have finished the prototype and have put up some sound samples.
Setup for demos: OB-8 (mostly set to a boring single-oscillator, unmodulated sound) -> JH Triple Chorus / String Ensemble Effect -> Reverb (String Ensemble Effect is sometimes bypassed to show the dry sound.)
Plain and simple string sound (1.1 MB mp3)
I start with a dry sound just to show you how much the Ensemble Effect is altering it, and I switch back to the dry sound towards the end for the same reason.
Enhancing a bell sound (740 kB mp3)
I think the effect is interesting for other sounds than just mere strings, as well.
Chorale sound (equalized ensemble effect) (470 kB mp3)
I wouldn't sell this as a specialized choir effect device, but it's certainly an alternative to the straight Solina-like stuff.
All done with the on-board 3-band Equalizer (which was inspired by the Crumar Performer).
Stereo effect using individual outputs (390 kB mp3)
Yes, we can do Stereo, with the individual outputs.
My first thought was to take the 3 individual outputs and mix them, one panned left, one center, and one right. But then the "Ensemble" effect falls apart, and the modulation sounds overly strong. I think you can do a lot of experiments with mixing the individual outputs, and will find interesting configurations.
The above sound sample was made with a very simple setup, however:
The full mix (main output) goes to one channel, and one individual channel goes to the other. The two channels are then panned almost (but not totally) left and right on the mixing desk.
Playing around with the EQ section (1.5 MB mp3)
Just some aimless turning of the 3 potentiometers in the EQ section, while my OB-8 arpeggiates away. I obviously change the OB-8 sound to something percussive towards the end, and I also adjust the OB-8's filter envelope setting slightly for the percussive sound, but I think it's quite clear what comes from the OB-8 and what comes from the Crumar-like 3-Band EQ.
Adjusting the waveform pot to find the "sweet spot" (790 kB mp3)
What is "the Solina Sound"? I think without any modulation waveform clipping (like the sound sample starts; please also see the discussion of this topic above!), is a tad overly lush for a solina. Or maybe it isn't. During this sound sample, I chance the modulation waveform from no clipping to almost totally clipped and back, and I think the "Solina sound" is where the waveform is just ever so slightly clipped.
This soft clipping (the "waveform" trimpot on the board) is different from a simple attenuation of the modulation CV. It's possible to attenuate (or to
boost) the modulation CV, too, by changing 3 resistors on the board, if you want to make further experiments.
More information, and pictures of the prototype, here.
JH."
