6 Responses to DIY Multiples

1. Jeff Laity says:

   April 25, 2008 at 3:00 pm

   Nice module. I just ordered one of the Bridechamber multiple panels. $40 for the kit, hell of a deal. I’m going this route since I’ll be able to split up future multiples, or do you find it advantageous to have them all of your mults in one place?

2. Richard says:

   April 26, 2008 at 8:05 pm

   The Bridechamber multiples are half of this size:
   http://www.bridechamber.com/bridechamber.com/Multiples.html
   A good deal at $40, since the jacks are included.
   Actually, I have a third multiple:
   http://pugix.com/synth/catgirl-synth-analog-logic-asr-cascaded-multiple/
   Putting eight multiples in one panel works well in a modular the size of mine, since the panel is located in a central location. In addition to the multiples, I sometimes use Y-connectors, available from Radio Shack. These are gold-plated and work nicely for the additional multiple.

3. Xavier Heindrichs says:

   March 29, 2010 at 6:43 am

   Hi!

   I’m finalizing my first version of a diy modular synth (yusynth modular). I’m trying to find the best way to make a multiple. My father thinks we need to put aop (ampli) component between input and multiple outputs to avoid an amplitude loss… (I’m not native speaking english, sorry!)

   Do you think he’s right? Could you send me a picture of the reverse of your panel (to see how you have wired all those ins and outs…)

   Thank you

4. Richard says:

   March 29, 2010 at 8:10 pm

   Hi Xavier,

   There is no in or out on a multiple. Four jacks are wired in parallel: all tips are just connected with wires, and all grounds are tied together. The third lug on the left-most jack of the second through fourth rows is wired to the multiple above, so they will chain if nothing is patched into that jack. This allows as many as 4 x 3 = 12 signals to be driven by one signal patched into the top left jack. (There are two groups of four multiples on this module.)

   Normally you won’t need to drive more than two or three inputs with your multiple. With typical output impedance of 1K ohms and input impedance of 100K ohms, driving four inputs is 25K (4 100K in parallel). Your signal will drop 1/25 (4%) of its original value. In most uses it won’t be noticed.

   One time you might want an active multiple is if you have to drive several VCOs at 1V/Octave and have them track perfectly. Many pitch drivers, such as MIDI converters, use a 100 ohm output that reduces the error. You would probably have more issues with your VCOs not tracking well of themselves, than caused by a multiple. In short, your father is mistaken that this will be a real issue. You don’t need amplification for 95% of multiple usage. Build yourself some passive multiple like mine and try them. They’ll work fine, I’m sure.

5. Xavier Heindrichs says:

   March 31, 2010 at 9:20 am

   Thank you very much for your reply! I understand a little bit more. As you can see, i’m a total noob in modular synth… Do you know a website where such things are explained for beginners?

   So you wrote we don’t need to drive more than 2 or 3 inputs with the multiple. But why to have te possibility to have 12 identical signals available?

   So, now, if I plug a sine lfo out and a square lfo out in the multiple, what will happen with those two signals if I plug a jack from the multiple to a vco in, for example? Will they be combined, summed? I know it can be done with the mixer, but…

   Is there a risk to combine different signals like this?

   So now, how could I do to drive 2 vco with one midi2cv controller if I want those to be perfectly tracked together?

   Thank you!

6. Richard says:

   March 31, 2010 at 8:41 pm

   Xavier, go to Muff Wiggler and sign up. You will get answers to all your questions there. Very friendly forum.

   http://www.muffwiggler.com/forum/

   Why have 12 possible outputs? It’s really just to make it easy to have more than 3. It can be 4 3-outputs, 2 6-outputs, a 3 and a 9 output. See?

   Combining two outputs like a sine and square LFO is not recommended, but won’t damage anything. Use a mixer for this.

   A midi2cv controller can easily drive 2 to 4 VCOs and VCFs with good tracking. Nothing’s perfect in analog modular synthesis, and doesn’t need to be. I didn’t mean to imply that.