606 rescued

A friend of a friend had me repair his 606. The Bassdrum was not working, and someone added some nonfunctional modifications, which were executed rather crudely. I mean, if you are about to drill holes in an enclosure, at least make sure they line up properly! All in all, the machine was in a really bad shape. It could not even be programmed properly, because most of the switches were bouncing or not reacting at all.

After getting the Bassdrum working, I took out the existing mods and added some of my own: in the top left is BD pitch, top right are snare pitch, snare snappy and snare decay. Because of the aforementioned misaligned holes I put a piece of black plastic under the knobs as sort of a cover up. 

To round it all off I installed a Technology Transplant replacement switchboard and replacement volume pots. Beware! The Technology Transplant kit is not exactly living up to its expectations: the switches on it are definitely NOT new, as they had solder residue all over them, and on two of them even one of the four legs were broken off! Also they, too, were badly aligned, which means that when I put the switchcaps on them and assembled the 606, lots of the keys got stuck in the enclosure because there was not enough tolerance. I had to resolder at least half of the switches.

Anyhow, the 606 is working beautifully now, the owner is happy, so am I. Bumblebee.

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.

Roland TR 606 - modded

Oh I wish I still had this one!
This is a Roland TR 606 drum machine with an external breakout box. The box features the following controls: Bassdrum PITCH, DECAY and TONE, Snare PITCH, DECAY and TONE, Tom PUNCH (switch) and individual TUNE controls, Noise LEVEL and Hihat FILTER. On its back are individual outputs for the instruments.

There is actually a small PCB with a completely redesigned Bassdrum circuit inside the breakout box. I still have the layout somewhere - I should probably dig it up and make it available to the DIY-community or the nice folks at the electro-music.com forums. I am toying with the idea of building my own drum machine, based on Marko Kanala's MR9090-Sequencer and an assortment of analog drum voices. The modded 606 BD would be a perfect fit.

I loved the 606's simplicity and ease-of-use and it's punchy analog sound. This is a poor mans 808! It is a bit of a shame that the photos are so blurry...
A great little box - sold on Ebay lightyears ago.

Roland TR 707 - Circuit bent

Tr 707 with external patchbay and individual 555-based oscillators that allow for tuning of the voices.
I do not own this machine anymore, some lucky guy bought it on Evilbay. Yes, I do sell stuff there.

Inside the TR 707. The new PCB that holds the 555s and the pots are visible.

External inputs for Hihats and Ride. They work like an audio gate- when you insert a plug the Hihats / Ride is silenced and the external signal passes throught the corresponding VCA. Gatelength can be set with the pots below the instrument buttons - great for chopping pads.

The banana plug patchbay, connected with a standard 25 pin sub-D connector. There is a 5x5 matrix for circuitbending mayhem. The 5x2 row at the bottom is connected to the switches - so your favourite connection can be switched on and off with the flick of a switch. Easy, fun and convenient. Oh, of course the plugs are stackable, for even more possibilities.