TR-505 Some Circuit Bending

Published on Apr 29, 2013 Oskar Schölander·24 videos

"Me making some random bends on the TR-505 for my upcoming bending and building project. More to come =)"

TR-505 Some key pressing

Published on Apr 29, 2013

SH-101 synched to TR-505
Published on Apr 30, 2013

"Just a test of my new circuit that converts the envelope signal from the TR-505 (the kick sound in this example) to a nice trigger output! Works perfect!"

latest phase of TR 505 project....... With MONOTRON!

Published on Aug 6, 2013 squidfanny·148 videos

squidfanny on eBay (RSS)

"Rusty old TR-505, revived from the dead for an audio experiment.
Inspired by Youtube user Oskar Schölander, this device is an experimental attempt to integrate a MONOTRON directly into a TR-505 drum machine!

How is this possible?

Using pulses from the MPU (big chip inside the 505), and an array of pulse stretchers/inverters, it is possible to trigger the Monotron and generate simple 'Computer Generated BAsslines'....

Take a look at the left side of the machine - can you see all the flashing lights? These lights represent pulses from the 505's MPU and also IC1. They are sent through diodes, to metal bolts. These bolts can then be connected to the Pulse Stretcher / Inverter modules to tweak the signal into something approximating a CV signal, which can then be fed into the Monotron - THUS TRIGGERING IT'S GATE, Pitch CV, FILTER & LFO.

I've also added Individual outputs for the TR505's drums, which can then be mixed into the Monotron's VCF...... Cool, eh?

Mods on the TR-505 include -
* ANALOG BASS DRUM (to replace the original pathetic excuse for a BD).
* Individual tuning for each drum group (courtesy of a cmos 40106).
* GATE Switches to shorten the drum sounds & give the machine more of a modern sound, suitable for faster tempo's.
* Individual Volumes
* Tone control for the snare.
* SEQUENCER GLITCH Mod, to disrupt the drum patterns by pressing buttons & switches.
* GLITCH Boltbay (not shown in demo due to annoying cat)

It's been about 5 years since I last touched this 505, and I'm ashamed to say it's just been sat in the garden shed for all this time, providing a nice home for lots of spiders....

It'll probably never quite end up finished, but it's still fun to play with as a canvas to try out experiments & test bits of DIY circuitry.
Future mods will include PULSE SHORTENERS (as well as pulse stretchers) & Some kind of interesting envelope generator. Possibly even a CMOS arpeggiator?
Monotrons sound pretty crappy compared to decent 'pro' gear, so may add a decent pre-amp / amp / tone circuit at some point too.
Basically the possibilities are endless.......

Watch this space and in another 5 years there may be a new Phase to this project :)

Thanks to Oskar Schölander for providing creative inspiration!

Oskar's original vid here -

http://www.youtube.com/watch?v=kliTPe..."

TR-505 VCA
Published on Mar 9, 2013 Oskar Schölander·24 videos

"I have connected the Monotron output right after R72 in this schematic:
http://i.imgur.com/5zoPsaa.gif"