Hello everybody.

I "discovered" something lately, and I cannot find much info about it so far. I'd like to share thoughts about it, and know whether this is a more or less common and known approach.

It is easily possible, to patch an audio mixer which has some kind of aux sends and EQs per channel, in a way that the mixer will behave very much like an analog synthesizer, but based on feedback signal. You still get it all - different waveforms, weird shapings and maybe some FM too.
You just have to connect an aux send jack with the input of some channel. Then you turn up the aux send level for that particular channel, and either voilá! - you hear something right away, or you hear nothing yet, and need to tweak some knobs there to get it going. Once you have a stable feedback signal, using the gain control and the EQ controls, you will rediscover many familiar analog synthesis features, layed out over your gain/eq/send controls. Like suddently your high eq knob controls oscillator waveform or frequency, or some kind of LFO, with speed and intensity, modifying the oscillator frequency. I only played around, I didnt need to figure it out in detail yet, back then.

Especially when you use two aux sends and two channels - I actually only tried it that way - it rocks! You can have the channels affect each other create weird effects.

Now... It seems at first that sometimes, the signal just drops out. It's gone, every now and then, and you hear nothing. Then you have to to get it back up by tweaking the knobs.
But when recorded on the computer, you can see that while the signal passes out, and you couldn't hear anything, you still have LOTS of signal. Obviously at inaudible frequencies, but at steadily very high levels - constant mega peaking.
Didn't damage anything, worked fine, I recorded it via the line in of my PC.
This setup - a mixer and 2 cables - is a crazy instrument, and I recommend it to anybody who has a mixer, two spare bigjack cables, and the interest

Now, the question that arises for me is: Is it mandatory to use a limiter or something like that just 'behind' the main out?
Could those signals be seriously harmful to other equipment?
It didnt seem to have effect on my cheap onboard PC sound chip. But who knows.

Could you call this setup an analog synth?

I plan to buy this mixer here http://behringer.de/MX602A/index.cfm?lang=ENG
solely for this purpose: Acting as an experimental crazy synth module.
This thing is so cheap, it's totally worth the shot.
I just wonder, whether It's a mustto also afford something like this http://behringer.de/MIC100/index.cfm?lang=ENG
to "take care" of the signals.
But whether it would tame those signals from peaking is another issue.

Is this technique/setup commonly known?
It's so simple.. when I look back now, I wonder why I didn't try it out earlier.

ALright. thanks in advance, and cheers! Try it out for yourself sometime, but maybe not with your primary hardware :-)

UHH: WARNING!! I am not responsible for any damage caused by what I described above, since whoever tries it out does so in his own responsibility, okay?