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I bought this last year, just minimizing my Eurorack setup.  Is in very good condition with some rack rash. Comes from a smoke and pet from home.  This is amazing VCO based on the X-4046 project and is a real hidden gem.  Massive value for the money!

I always ship with Reverb shipping Protection.

Here is some info about the module:

A CD4046 BASED VCO
As CMOS ICs go, one of the most compelling for us (and by "us" I mean synthesizer DIY geeks) would arguably be the CD4046. How can one resist the fact that this IC has not one, but two types of phase comparator built into it, along with an integral voltage controlled oscillator to boot? This is not your simple logic gate, multiplexer or shift register, but an IC with a combination of features one can really sink his teeth into.

Obviously the potential of using the CD4046 for musical applications has not been overlooked. For example, Scott Gravenhorst designed a great harmonic multiplier around the IC and the CD4046 forms an integral part of Grant Richter's famous Wiard Wogglebug.

Musical instrument designs based around the CD4046 tend to concentrate on the phase locked loop application the CD4046 was intended for in the first place. Most often, the 4046 is made to lock (however tightly or loosely) onto an incoming signal and produce the desired musical effect based upon the phase locked relationship with the external signal.

These applications, as well as others through the years, have proven to be very interesting and effective. However, what generally seems to be ignored is the usefulness of the VCO itself, and there is small wonder in that fact: in its native form, the VCO is a rather lackluster linerally controlled device that produces a pulse wave output. Why would one use a CD4046 as a VCO when a much simpler dedicated device such as a 555 timer can produce essentially the same results? Leave it to Thomas Henry to answer that question. Who would have supsected that by using a circuit that contains a mere four ICs and strategic manipulation of the IC itself, one could coax the following out of a CD4046:

Exponential Control and Modulation of the VCO
Linear Modulation of the VCO
Five unique waveform outputs (triangle, sawtooth, pulse (PWM), sine and variable rampoid
One of the finest hard sync effects ever heard from a VCO
Taking those features into account, the CD4046 VCO in itself suddenly becomes considerably more interesting.



THE X-4046 VCO
As it turns out, the CD4046 VCO, under exponential control, can be a surprisingly compliant VCO, given that the CD4046, in all likelihood, wasn't designed with the intention of the device being used to play the solo from "Lucky Man". It certainly would not fall into the class of a CEM3340 (if it did, there would have been no need of the CEM3340 back in the day), but given enough care in build and tuning, it can certainly hold its own as a solo VCO.

On Thomas breadboard, he was able to get a very decent seven octaves out of it. Below is a link to his results:

Not too shabby at all! The best tuning results I was able to get out of the VCO weren't quite so close - I had a bit of trouble keeping things from going slightly flat at the high end, from around 2400 Hz on up, but at the same time found the VCO to be quite usable with my keyboard and my ribbon controller, and certainly with a sequencer. For the size and very low cost of the circuit, it more than delivers in a number of ways.

In fact, this would be a great VCO to incorporate in many projects - I think it would be a great application to put a couple of these together in a stand-alone portable synth. The exponential control makes it easily controllable with either a pot or a ribbon controller, and provides the ability to patch in that all-important vibrato effect. In any event, I invite you to try this circuit out. You may very well find it's just the circuit you were looking for in that particular application....

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Listed2 years ago
ConditionExcellent (Used)
Excellent items are almost entirely free from blemishes and other visual defects and have been played or used with the utmost care.Learn more
Brand
Model
  • Thomas Henry
Categories
Made In
  • United States

Red Stapler Worldwide

Kutztown, PA, United States
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