sound labs mini synth questions

hey, this is my first post, although i am a lerker....

i am building the mini synth and i had a couple of questions:
1) in order to produce sound it needs a control voltage, right? so i had the idea of adding a cv knob and button to the case.........that would allow me to press the button and sweep the knob and, hopefully, get some crazy noises.
how would i go about supplying this voltage..........i basically want the mini synth to be a stand alone device as well as be able to be controlled by a keyboard. so what i was thinking was making this cv knob patchable, i.e. make an output cv that i can patch right into the input cv of the synth. does that make sense?

2) my other question involves the power. i know that it runs off of two 9v batteries. can i get a wallwart to supply this power instead? have the option for both?
if i were able to get a wallwart to supply the power, can i use the same wallwart to supply the cv power that i mentioned in qestion 1?

thanks guys,
ryan

You already have a CV knob on the oscillator of any analog synth - the tuning knob. Just adding a pot with a DC CV will just duplicate the tuning pot and not really be helpful. As for a button, you would put it on the VCA to switch it on so you could hear the oscillators, or on the gate/trigger circuit to fire the envelope generator. These are just general synthesiser principals, I haven't seen the Mini synth to know how it is configured.

To run a dual 9V battery device from a wall wort would need a simpe circuit to be addrd to the synth, basically a few diodes and capacitors along with a 7809 and 7909 regulator.

cool thanks

Here's another option for +/-9V from a 9VDC wallwart...
http://www.geofex.com/circuits/+9_to_-9.htm

I've used the MAX1044 like this in a Maestro Filter/Sample & Hold clone with great results. So, I'm planning to try it in the mini-synth, too.

~ Charlie

I wonder if the MAX1044 would be able to deliver sufficient current for an entire synth, to keep the VCO's from pitch drifting each time another module or an LED pulled current? VCO's are not as tolerent as stomp boxes to slight voltage instabilities.

I don't know about that particular synth, but I would think a couple of CV pots and at least one trigger pushbutton would be nice. (in a handheld case of some kind) Maybe throw in an LFO too. Then you could modulate VCO pitch, VCF cutoff and/or VCA amplitude for a lot more expression. You could even use force sensing resistors for a touch sensitive CV source.

Click to expand...

thats what i mean.........
basically i am building this thing in an old geiger counter.....it is going to look sweet. the pcb that i got from sound labs mounts perfectly on the posts where the old geiger counter pcb used to be.
i was going to put the knobs and switches all around the case, but i wanted to control the pitch from the case as well (i.e. no keyboard)......so if i could put a pot or two and a pushbutton i think that would be money.

if anyone has an idea of how i could do this, please help,
thanks
ryan

Hi all.

I build mini synth lab i have problem because my osc1 don't work.

How voltage must be on Q1 Q2 ....etc.    ??


Best regards