Constructional difficulty: Easy
The Multimix comes in three variants: Left; MultiMix Standard. Middle; MultiMix 'Stooge'. Right; Multimix Sum
A highly useful utility module that can be obtained in three variations.
MultiMix Sum
The basic version of the MultiMix. This operates as a standard mixer. Up to three inputs, either CV or audio, can be summed or mixed together. The levels for each input can be set by a pot. The gain can be set from completely off to a little over one. Two mix outputs are available: One is +OUT and this is simply the three inputs added together according to the levels set by the pots. The other is -OUT and this is an inverted version of the signal at +OUT. This means if the output from +OUT is +4V, then the output from -OUT is -4V.
A bicolour LED is also featured. This will glow when a signal is present at the outputs. The higher the output the brighter the LED. The colour of the LED will be determined by the output polarity. It will be red for mostly positive output voltages, and green for negative.
MultiMix Standard
This one is similar to the MultiMix Sum, but instead of ordinay pots to set the input levels, this one features three reversible attenuators. Each control knob can be set so that the gain of the input is anything from -1 to +1. This means that not only can inputs be added together, but can subtract as well. With each input knob set to its middle position, then none or very little of the input signal will reach the output.
Mixer's with reversible attenuators on their inputs are very useful for controlling audio and CVs. One excellent application uses a MultiMix with a VCA to create a very flexible ring modulator.
MultiMix Stooge
This one is similar to the MultiMix Standard and has the three reversible attenuators controlling the input levels. However, this one features a clever combination of three output sockets to achieve a variety of uses.
Inserting a jack into OUT1 and you will find a controlled version of the signal going into IN1. The pot will control the level of the signal as well as its phase. You can thus use this to attenuate, or invert, CV or audio signals around your modular. The other two input channels will work in a similar way.
But if you don't utilise the OUT1 jack, then its output will automatically be summed with IN3 to form a mixed output at OUT3. Likewise, not using OUT2 will make its output join with the IN3 signal too. So you can use this module as a standard MultiMix if you don't use the OUT1 and OUT2 sockets.
Although the three variants use different front panel designs, all are made from the same PCB. The different versions are simply selected by using different components and inserting some wire links into the board.
The issue 4 PCB set
The issue 4 MultiMix module features a two PCB set. Previously, many Oakley modules have had the sockets, switches and extra pots wired to the board by individual wires. The new MultiMix allows all the socket wiring to be done via an extra PCB and two MTA solderless connections. If you are building this module in the standard MOTM and Oakley format this new system will reduce assembly time and possible wiring errors.
Some people will wish to use this Oakley design in a non standard format, such as fitting it to another manufacturer's rack or one of their own invention. This is perfectly easy to do. Simply do not use the socket board and wire the main board to the sockets as per usual.
The MultiMix Stooge module from the rear showing the separate main and socket boards.
Parts prices
MultiMix issue 4 PCB
................................... 21GBP
MultiMix issue 4 pot kit ................................. 9GBP
MultiMix issue 4 pot bracket kit
................... 3GBP
The Pot Kit contains the correct type and quantity of Spectrol 248 potentiometers to complete 1 module.
The Pot Bracket Kit contains the correct type and quantity of Oakley-Spectrol pot brackets and extra Spectrol nuts required to complete 1 module.
Click here for full price list and ordering details. All prices include VAT at UK rates. Shipping and postage is additional to these prices.
Project Downloads
User Guide Containing full building instructions and parts lists for all three variants.
Schematics are now available as a 'pay per download' service. Any modular schematic can be purchased for 2UKP each. The purchaser agrees that the schematic must be used for personal use only and not to be sold on or allowed to be re-transmitted in any way. These diagrams are copyrighted and any infringements will affect the future use of this service to others. PCB layouts will not be made available as yet.
Parts lists for US builders
Builders based in North America can now find full parts lists, complete with order codes, for many of the Oakley modules. Larry Hendry has kindly provided the web space for customers to upload parts lists. Go to www.wiseguysynth.com for full details.
MOTM style Front Panels
See Dave Bradley's great service using real MOTM blanks to create perfect MOTM compatible panels for some of the Oakley Modules : www.hotrodmotm.com
Front Panel database
The1U wide Schaeffer front panel databases can be found here: Stooge, Standard and Sum.
To read these files you will need a copy of 'Frontplatten designer' from Schaeffer. The program also features on-line ordering, so its now even easier to buy your panels from Scheaffer.
The company is based in Berlin in Germany and will send out panels to anywhere in the world. Delivery to the UK normally takes around ten days. For North American users you can also order your Schaeffer panels from Front Panel Express.
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