Wednesday, 29 March 2017

Buchla Preset card - DIY mixer for 208 easel

One of the best things about the Buchla Music Easel is its program card.
It's really not just for presets ... esp the original card invented by Don Buchla back in the 1970s.


I'm guessing he may have wanted us users to experiment with electronic circuits.
Why else would Don have placed a mini "breadboard" with +/- 15V rails on the program card?

The Buchla SILI-CON CELLO from 1978 is a good example of his use of breadboard circuits in a fully
functioning system. It's a shame the current BEMI program cards have removed this homage to the age of DIY electronics.

This is my latest use of the card: a DIY mixer.
(The 10U system doesn't have a dedicated mixer).

The circuit is very simple.
Just one dual op-amp (TL072)

It's a basic unity gain inverting configuration. In the first half the 4 inputs are mixed into the inverting input of a op-amp. Since the output signal from this op-amp is inverted, the 2nd op-amp  re-inverts it. 
Power goes to pins 4 & 8. The unmarked resistor on the right is 1K

Thanks to Ken Stone for the original circuit. and Justin from MetroModular for his advice.
Ken's schematics show the possibility for using this as a CV mixer & attenuverter.

Breadboarding the circuit. Just two inputs on the left without pots.
It works on +/-12V above and +/-15V below.

Might try building a mixer using the OPA2134.
It's pinout is the same as the TL072.

Friday, 24 March 2017

Buchla rhythmic patches - 200e & 208

Finally getting a easel system together which combines the 208 with 200e.

I've had this beautiful 10U case (by Jason Butcher) for a few years now.


Was in a quandary as to which modules to put in. Should it be all 200/ 200& 100 combo
or 200e?
 As the case is a variation of the classic Music Easel case from the 1970s (Halliburton)
a 208 is obilgatory.

I've decided to go with 200e for now.
It's good to have something different to the standard easel configs.
Seems like a good combo.




Wednesday, 22 March 2017

Critter and Guitari Cellular Automata



Links re Cellular A:
Muffs - code
Github - more code
GetLoFi - DIY kit
Critter and Guitari - website
Circuit bent CA synth
Wikipedia
Muffs 2 - Mr Coops
Muffs 3 - PCB buy

Critter & Guitari Cellular Automata Synthesizer from Critter & Guitari on Vimeo.

--------

...
 Critter and Guitari Cellular Automata Synthesizer by Owen Osborn

I'm building a DIY version kindly provided by "n167tx" (Muffs)

The parts list is on the right.
You need to download the eagle file and upload to this viewer:
http://3dbrdviewer.cytec.bg/board


Eagle has a free viewer.
Download here:
http://www.autodesk.com/products/eagle/overview

Microcontroller used:
The AtMEGA8
http://www.atmel.com/Images/Atmel-2486-8-bit-AVR-microcontroller-ATmega8_L_datasheet.pdf

The AtmelAVR ATmega8 is a low-power CMOS 8-bit microcontroller

Links re AVR programming.
1. PocketMagic
2. Instructables
3. Youtube
4. youtube 2


Sunday, 19 March 2017

Ambient Electronica - Elektron - Mutables - Buchla

Some recordings taken last Friday (17/3/17).
Rory, Andrew & I are practicing for an upcoming gig.
Instruments used were an Elektron A4, Roland TR8 Drum,
some Mutable Instruments Euro modules and Buchla-Sputnik clone modules.