Power Supply

A synth is nothing without a power supply. So I've been looking at the available options to power my new rack.

The obvious option is the Blacet PS505, which is rated at 500mA. The problem is the modules I currently have planned will consume around 460-470mA, plus I have left a couple of gaps in my rack for other modules, so I'd be a bit worried that I'd be pushing supply beyond its limits. Then I need to factor in that being in the UK, by the time I've paid shipping it works out at almost £100, not including the usual import duties/VAT/admin charges that usually add on another 20%. So it starts to look a rather expensive option.

The other options are all DIY based.

First off, there is the Oakley power supply based around a Yamaha power pack that should safely run up to 750mA. This is quite a good option as there is a minimal amount of wiring up to do, apart from having to build up the supply board.

Next up is an open frame Linear type supply from Power One or Calex. These are available in various configurations & current ratings, but require more wiring up to get the required power options.

The other option is a Traco switch mode power supply. These are enclosed and deliver around 1A. Wiring up is minimal, and as it is enclosed the risks are lower. However, I'm yet to find a definitive answer as to whether switch mode supplies are good to use with modular synths. They usually are more noisy than regular linear supplies.

So at the moment, I'm undecided. I've narrowed it down to either the Oakley DIY option, or the Traco option (if I can find out for sure if switch mode supplies are OK).

Decisions, decisions...

Attenuverting Mixer

I have populated my Attenuverting Mixer PCB from Fonik. I have been working on the front panel layout using Front Panel Designer.Here is what I have so far:

In my layout I have removed the switch and have separate outputs for AC & DC. I need to order some pots, then I will print this layout out and put on to some cardboard to try the components out to double check the hole sizes and positioning.

Thinking of Modules

I've been thinking about which modules I might have in my new Frac system.

I've already got the Blacet 2790 Mixer, plus a Lo Pass Gate PCB & Attenuverting Mixer PCB. Others I'm tempted by include:

FOH Plague Bearer
Blacet Midiverter
Blacet Micro LFO
Blacet Mini Wave
Blacet Dual VCA
MOTM Moog VCF
Synthasonic Phaser
Metalbox Digital Noise
Metalbox Psycho LFO

I can feel some Rackplanner sessions coming on...

1st FRAC module

So I've got my empty case for my second modular, but no power supply. I've got plans to DIY a couple of modules. In the meantime I saw a fairly cheap Blacet mixer module going on eBay, so I grabbed it! And it's arrived.

It's the small 2790 mixer module. Although I will be DIYing another mixer module, you can't have too many mixers. Plus it's handy to have a proper FRAC module around while I finish up my case.

I can't do anything with the module yet, but it's nice to know I've made a start on my new synth :-)

My Next Synth

I've got just enough room to squeeze in another small modular. Yay!

I can just about squeeze in one of the Ikea 'Rast' cases, which is the ideal size for two rows of FRAC format modules.

What's going in it? Who knows!

I've got an Attenuverting Mixer PCB from Fonik, and a LPG PCB from Thomas White, so it will be those two modules at least. I'll make it up as I go along, but I want it to be able to be used as a synth in it's own right, as well as being an extension to my current MOTM modular. I guess I'll have to make some patching panels to convert between the two systems. Oh yeah, I'll need a power supply and another MIDI-CV converter.

My Current Synth

My current modular synth is based on the '5U' MOTM format. Modules include 2x MOTM-300 VCO, 1x MOTM-310 VCO, 1x 820 MOTM LAG, 2x MOTM 320 VCLFO, 1x MOTM 120 Sub-Oct, 1x MOTM-420 VCF, 1x MOTM-410 Triple Res Filter, 1x MOTM-110 VCA/Ring Mod, 2x MOTM-800 ADSR,1x MOTM-101 Noise/S&H, 1x Oakley Multimix, 1x Oakley COTA VCF, 1x Oakley Superladder VCF, 2 x Oakley Little VCA, 1 x Oakley Little EG.

Phewww, I remembered them all :-)

I started this synth in about 1999/2000. Most of it was DIY built, but I got the 410 ready built and recently the Oakley COTA VCF ready built as well.

I'm very constrained by space, so this is as big as this synth will get. However, in my workspace I have worked out that I can fit in a small extra system, so my lust for more modules will have to be satisfied there...