v/oct to v/hz converter

[Magnus Danielson]

From: "Gerry Dahl" <gerryd at ntx-tech.com>
Subject: v/oct to v/hz converter 
Date: Wed, 26 Jan 2000 16:11:17 -0600

> Hi Everyone,
> I have a problem I need a resolution to. 
> I have a synth module that is controlled by v/hz and I want to control it
> with a v/oct controller. Is there a circuit I can build to do this?

Yes.

Take the exponential core of choice (like the ASM-1 VCO
http://home.swipnet.se/cfmd/synths/friends/stopp/) from a VCO.
Then, from the second transistor you take the current into an I/V converter.
The I/V converter you build from an op-amp and a resistor, setting the
resistor between output and (-) input. You hook the expo converter's current
output to the (-) input of the op-amp. The (+) input is hooked to signal
ground. Select or use trimable feedback resistor to set V/Hz scale.

Tada!

I think I have described exactly this just a week ago or so...

Anyway, it should be a pretty straigth forward thing to do.

Hmm... maybe it is time to actually make a V/oct to V/Hz converter schematic.

Either way, it is even simpler than doing an VCO.

Good luck and much fun!

Cheers,
Magnus