Feeler: VCQO Circuit Board

[DZ]

Hi all, I've been kicking around the idea of printing up a couple VCQO boards for experimenting with other projects and wanted to see if there was any interest in these. This is the same VCQO that's in the Z-5, originally designed by LSDC. This is a very solid quadrature oscillator providing a very clean sine and cosine wave, there are 7 of these in the Z-5; 3 for the regular oscillators, 3 for the rotators and one for orbit. It has 2 inputs to control output frequency, you only need to apply +/-15V to one input to get it to work. The second input can be from another signal source such as an LFO. This outputs sine and square waves. In the Z-5, for the 3 main oscillators I use .0047uF caps which gives up to about 600Hz. For rotation on the Z-5 I use .22uF caps which gives about 10Hz with + or - 15V on the input.

When the input signal is at +15V the oscillator is running at max speed, which is dependant on the timing caps. As you reduce the input voltage the frequency decreases until you reach 0V on the input, at this time the output frequency has stopped and as you continue past 0V and head toward -15V the sine/cosine signal begin going the other direction.

So, depending on the number of boards I can have printed, I'm hoping to be able to offer these at around $50-$75, plus shipping. Or maybe just the bare boards if you want to populate them yourselves, I'll have to check on the per board price, likely around $15 but again it depends on the number of folks that are interested.

Here's a quick demo video of the output of the VCQO: https://www.youtube.com/watch?v=s_LK76BnjF0

I've also attached a pic of what the board would look like. Disregard the silk screen layout, a few changes still need to be made to clean it up, but this is about what it will look like. Also, the board measures in at 100mm x 40mm



Any interest in these?

[andy_con]

sorry

what is it?

[CountFunkula]

YesPlz!!! Interested!

[DZ]

sorry

what is it?

A quadrature oscillator is the foundation for an analog console. It's the "old fasioned" way of making abstract, all analog, no digital. Having a high quality quadrature oscillator is extremely important and this particular design does a fantastic job.

CountFunkula, you in for 1? I'm thinking I'd need about 5 or so. I don't think it's going to be cost effective unless we get about 20 or so on the list.

[SaltyRobot]

I would be in for at least one. Possible two by the time SELEM rolls around. Not sure what your time frame for this is but one for sure. I would want fully populated ready to output for 50-75.

[Bbe]

Why not just use DDS generator for this?

[absolom7691]

I'm interested. Would be fun to try and build one.

[LaNeK779]

Why not just use DDS generator for this?

this is my question, too

However, i' m in for 1 to help get you to the desired number

(i suppose there will be smd parts involved, making it not too easy to assemble one myself, right?)

[DZ]

Why not just use DDS generator for this?

I know this can be done digitally, heck, maybe even cheaper? There is just something about the analog circuits that I prefer. I can't really explain it, I suppose. My step father runs a guitar shop and was in a band many decades ago. Even to this day he swears by the old tube amplifier. Perhaps an analogy can be drawn from this. Similar to the old ions.

It is also a lot easier to turn a few knobs and flip a few switches than it is to point and click...

So it looks like I'm at about 9 boards at the moment.

[ekeefe]

Hello,

I would like 2 bare boards.

I hope this helps you get the cost of the boards down for everyone.

ED