Mattson VC Mixer

Quantity: 1

Description:  Mattson Mini-Modular Voltage Controlled Mixer

Here is a MOTM-ized Mattson VC Mixer!  From the Mattson website:

The VC Mixer consists of 4 channels.

Each channel has an associated gain control and control voltage input.

There are two outputs; Normal and inverted.

The control inputs respond to a 0-5V control voltage input. 0V is fully attenuated and 5V will produce a 100% output level.

The Level control attenuates the channel level.

The control inputs are cascaded. 5V is applied internally to the Control input for the channels and cascaded from channel 1 to channel 4. This allows the module to be used as a 4-channel mixer with no control voltage input to the Control in jacks.

When a Control input is plugged into a channel Control in jack, it interrupts the 5V from that channel through channel 4 allowing the gain for that channel, and all subsequent channels to be controlled by the new control voltage. New control voltages applied to the subsequent channels will interrupt the preceding channel control voltage for that channel and be applied to the remaining channels.

The trim pots on the circuit board are labeled with the associated CV gain adjustment and are set for a 1:1 input to output ratio. They can be trimmed to provide additional gain to utilize the mixer as an amplifier, if so desired. The gain will clip the original signal and can be set to overdrive the signal into a square wave peaking at the positive and negative power supply levels.
The mixer will work with both audio and CV inputs.


I used a Front Panel Express Panel of my own design, based on the MOTM jack grid like other recent panels I’ve been making.  This grid allows fitting more pots into a smaller area.

Bracket parts

The Mattson PC board is just a tad too wide to fit on a Bridechamber 3-jack bracket.  I made an adapter bracket out of thin aluminum stock I got at Lowes.  The adapter bracket mounts onto the Bridechamber bracket and then the board to the adapter bracket.  This photo of the bracket shows the bottom side that attaches to the Bridehamber bracket.  I matched the holes up to existing holes in the BC bracket, drilling out to 1/8-inch to work with some old PC motherboard standoffs I had.

Wiring up a Mattson DIY board is easy if you purchase the corresponding wiring kit.  All I had to do was to trim the wires and connect them to the panel parts.


4 Responses to Mattson VC Mixer

  1. aliis vorbach says:

    I have always liked the idea of a vc mixer and that one looks really good and does both ac and dc signals. How hard would it be for a diy NOT person such as myself to build and what was the price of it all. I presently have 6 Q112 but would really like vc in my mixers. well done. aliis

  2. Richard says:

    George Mattson sells the assembled and tested VC Mixer board, plus the wiring kit, for about $100. He also has a full 5U kit with everything but knobs for $175. Check it out.

    If you did one exactly like mine it would cost a bit more, because the Front Panel Express panel runs about $70.

    As for difficulty, this is pretty easy. All you have to do is assemble the mechanical parts and solder the wires to the pots and jacks. Would make a nice first DIY project. Practice soldering first! Look up soldering tutorials on youtube.

  3. aliis vorbach says:

    That we mixer looks and sounds like a little gem. i might have a go at this but i need to know more about making panels which almost seems to be the most dificult thing with diy. And of course I would be wanting mine in a DOTcom style panel with dotcom knobs. Still i really like your own version and I may consider a motm format though what i dislike about motm style panels apart from their knobs is they have no white legending around their pots. When I can figure a way like everyone else on this diy stuff to make some panels I would consider some of these projects. I also like yves yusynths ring,logic and minimax look interesting and love the job yves has done on those dotcom like panels. They may also be good first projects tho there is some calibration on them. cheers and all the best. oh I would love to hear some sounds of your synths,where can i find a link to anything you have done? aliis

  4. Richard says:

    That bracket is way too complicated. I’ve since started making brackets out of Lowes aluminum sheet by itself.

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