Sunday, July 4, 2010


Throbbing Gristle is a quite influential Industrial band. Part of what makes their sound unique is the infamous Gristleizer, a distortion unit built by bandmember Chris Carter. It has a LFO with four waveforms which controls a VCF or a VCA. There have been numerous DIY clones and there is even a commercial re-issue available (for about 400 USD, which I find a little steep).
User Taylor from the forums (I love that forum. Honestly.) offered a PCB for a Gristleizer clone, and I ordered one.
It has all the original features PLUS an output for the LFO - which means the thing integrates rather nicely into my modular synth. The input / output jacks are located on the front panel for that very reason. The panel is aluminum, the case itself a mixture of sheet metal, plywood and loads of gaffa tape.

Tuesday, June 29, 2010

TR 505 XL

This is what happens when you give me a TR 505.
The 505 is a digital drummachine made by Roland. It has a nice, easy-to-use sequencer, a big display, full MIDI capabilities and some of the most boring sounds that you'll ever hear...
Time to mod it, I'd say!
It now sports single outputs (1/4") and trigger outs (1/8"). Especially the trigger outputs are quite handy for owners of a modular synth... the 505 will work as a MIDI-to-trigger converter too!
Also the sounds are now tunable - I added 8 new oscillators (this time 40106 based, unlike the 555 based ones on my TR 707) to accomplish this.
I also added volume controls, so now there are 16 new knobs on the front panel. The volume controls are doubling as a"crunch" control, which goes like this: the maximum volume is reached at the 12 o´clock position (and the potentiometers have a center detent to reflect this), turning the knob further to the right will overdrive the internal mixer stage a bit, resulting in a slightly distorted sound. This adds a nice punch and grit! Due to the way the mixer stage is designed this will only work on the main outputs.
Most of the necessary informationon how to do these mods can be had from the Burnkit2600 TR505 page, so thanks to those guys!
All that stuff did not fit into the stock enclosure, I had to make some side cheeks out of stained plywood in order to raise the height of the case by 3cm.

Check the sound sample below for a glimpse of what this machine sounds like. No FX, no overdubs, no EQ used - recorded straight from the master output.

Monday, June 21, 2010

x0xb0x, again

So here it is, my second x0xb0x. This one has been finished for ages, but only today it occured to me that pictures would be nice.
It is completely self sourced, which means that I did not buy a kit but aquired all parts separately. Likewise there is no official Adafruit serial number.

The frontpanel was made by Schaeffer Apparatebau in Berlin - this one has far too many modifications for the "stock" panel. The legend was made with Lazertran.

The mods are:
PWM for the square wave
Accent Sweep Speed selectable between fast, normal and slow
Accent Decay control
Filter Overdrive with "color" knob
Bass Boost, Resonance Boost (with separate pushbutton switch and LED indicator)
"Eternal Bliss" - this is a combined Gate On Forever / Envelope On Forever to get those liquid acid lines
Filter Modulation with selectable source (square, saw, VCA) and two modes (buffered / unbuffered)
Envelope Retrigger button
VCO out / Filter in on TRS socket
orange / amber 3mm LEDs
Sokk0s 1.9 operating system

Sunday, February 7, 2010

STOMPIT - Dual FX Pedal Level Converter

Any seasoned Synthetisist knows that the voltage levels in your modular synths are much higher than the ones you'd feed into stompboxes. So, if you patch your VCO straight into, for example, your Boss FX pedal, you will get some nasty overdriving and clipping. Mind you, this distortion actually might be nice, but not desired at all times.
My good pal Waktu Loopa asked me if I'd be able to help him getting his levels right. My solution is the device pictured below: a dual FX pedal level converter. It's made to fit in his Doepfer A-100 modular system and should work nicely with his collection of stompboxes from Orion Effekte. (I tested it with the Benjamuff PI featured in my previous post.)
I designed the PCB and the frontpanel myself whilst the circuit is inspired by the invaluable genius that is Ken Stone.
The keen eye might wonder why there are some odd componends on the circuit board, most notably the HUGE 2W resistors. Easy: I am a sexy Recyclotron and so I used what I had on hand. That sometimes means that I pull components from junk electronics (always remember: recycle or die)
Because I am such a nice guy I wrote him a manual as well (he's stupid and I had a lazy sunday evening to waste). Now all that is left is to do is to actually send him the thing. As much as I hate to part with the module -I am sure it'll be in good hands.