Guþ Cleadur - Theory + PSU
A sloppy drawing on a strip of paper. That's how it always starts.
This rainy easter weekend, I started working on a new project I've been pondering with for quite some time now:
The Guþ Cleadur (Guth Cleadur= "war bongo") is a semi-modular synth control unit comprised of two channels with four sections each.
- Rhythm:
Both channels share a master clock (555 Timer based on Synthrotek's design) the pulses of which will be sent through a clock divider (based on Fonik's design) that will output 6 basic clock divisions (1, 1⁄2, 1⁄4, 1⁄8, 1⁄16 and 1⁄32). One of these can be assigned to each channel individually via 1P6T rotary switches.
There will be breaking trigger inputs as well to allow for more complex rhythms from my modular system or whatever to override the internal Rhythm section. - Human interface:
The main inputs are a pair of 80x80mm capacitive touch plates made from 2mm copper sheeting, the "bongos". These will produce gates that iteract with the triggers from the Rhytm section, thus allowing for some human error as well as control.
As for the rest of the interface - there is still a lot of uncertainty about which way to go. One day I'll think that a plethora of ins, outs, switches and buttons will make this machine even more usable, the next day I want to keep it simple and clean - not over-complicate things.
We'll see what I come up with on further inspection. - Logic:
This is where the magic happens. The outputs of Rhythm section and Human interface are combined by one of three logic circuits (probably based on Doepfer's DIY-Page), selectable by means of a simple spdt switch for each channel:
off will disconnect the Rhythm-Section from the rest of the circuitry, making this channel's bongo the only trigger source.
and will effectively turn the bongo into a momentary off-on switch for the Rhythm section's output.
or will allow for some happy little human bursts between the strict triggers from the Rhythm section. - Envelope:
Whatever pattern of triggers/gates is produced by the Logic section is buffered, output and sent to the Envelope section (based on Dintree's D101).
This envelope design is quite versatile and compact: It's a digitally controlled two-channel envelope generator each channel of which can be set to either adsr, ar or lfo mode.
The signal is output and a copy is fed through a simple attenuator and then output.
I got this Hyland DIY Wallwart-PSU for cheaps (~10€) a few weeks ago just for the hell of it. This weekend it hit me: It seems almost specifically made for the Guþ Cleadur unit as it outputs 300mA each for +12V and -12V which is needed for the clock & divider, the buffers and part of the envelope section, 300mA of +5V which will drive the digital bits of the envelope and most of the logic circuit, probably. Plus, it offers 300mA of 3.3V, the ideal Voltage for the capacitive switch chicklets I'll be using.