Modular synth madness

To give you an idea of the complexity of the system - the Moog 3P, as used by Tangerine Dream, typically had 3-10 oscillators. Mine has 18 multi voice ones. I can output 48 simultaneous waveforms. The Moog could do 3-10.

One of the Moog oscillators could be switched into low mode to act as a low frequency oscillator. I've got about 8 LFO's in the system.

You'd have one or two filters in a Moog. I have something like 12. 

There were usually a couple of envelope generators in the Moog, I've got about 12 as well, plus slew limiters. 

A sequencer was an expensive optional extra in a Moog modular. I have 8 secondary ones, two master ones and two two channel backups. 

Hi,

Davesax1965 wrote: Good stuff, Mosh. ;-)  I must get something like that. Otherwise people might not think I'm serious about old synthesizers. ;-)

Less than a quarter of the synth. 

It's a pity that spaghetti isn't conductive, I'm going to need a lot of patch leads. 

"I wonder what this knob does ? " 

"He builds synthesizers" ;-)

I didn't - am I missing something ? ;-)

(apart from any sense of proportion and logic, that is. ;-) ) 

Sequencers, all wired up to receive common clocks (so they all run in sync)

And this is where they live. Some reorganisation required to get the other case in. 

The sequencers produce the background rhythms automatically. There are two banks, the sequencers can be selected by rotary switch so you have a total of 8 patterns, selectable to run individually or in tandem.

In the interim, the other rack (which is being finished off) has a total of 8 oscillators in and produces the main lead voices. It'll be run (via MIDI) from the Arturia Minibrute in the foreground. There will also be an internal sequencer in the main case which provides master clock out to the sequencer case, keeping everything synchronised. 

The next step is to get the main 18U case built. I've got to add a back plate containing two power supplies and six distribution strips, then get the whole thing powered up. There will be another two or so output modules in the big case giving yet more outs to a mixer. 

Coming along !! 

Thus. And that's about half the setup. 


Edited by Davesax1965 - December 29 2018 at 03:10

Right, next step: build an 18U custom case. Or rather, get a custom flight case made for me. 

This is the zen of modular synth power. 

You've got frames, which the modules screw into. These are 19" rackmount jobbies, but there are standard non- rackmount frames available. Under the frames here are two "cheesegrater" power supplies which kick out 2.8 amps each, 12v DC. The feeds out are +12, -12, +5 and GND. 

You have an AC power inlet (IEC) which connects up to the power supplies (not shown). The power supplies kick out DC to the green PCBs, which are power distribution strips. (No wiring on here yet). The distribution strips - "bus boards" - have headers on them to connect the power to the modules via ribbon cables, again, not shown. 

All of this sits on a back board. I've got a bit of ply here, but the working board will be 2mm mild steel. The back board is insulated from the case (and AC in) by sitting it on square section aluminium. So, lots of cutting and drilling to do, which will result in lots of sailor language. After that, you switch the power on (hoping that you've not made any mistakes) - test the voltages and then plug the modules in with the right polarity, as reversing the +12 and -12v feeds has all kinds of nasty and expensive consequences. 

Job done after that. I'll have a couple of blank rows spare "for expansion purposes" - the real pain in the backside is calibrating all the oscillators, amps and filters in the synth. This can take AGES to set them up correctly. They're all tested and working, but getting them to sound right takes quite some considerable time and effort. 

Should be just insane when finished, though.