New MOTM module breadboarded

[Paul Schreiber]

Just finished the next MOTM module: MOTM-120 Sub-Octave Multiplexer.

It has 2 inputs and 1 output. The inputs are 2 clocks, either from a VCO or LFO.

Mode #1: Sub-octave divider

When the mode switch is in SUB mode, the input signal into Channel 1 is squared
and then sub-divided into 4 octaves. The input is then mixed with the 4 sub-octaves
(all with panel pots). There are switches for each input to select mixing in the original
input or the "squared" version of the input. Any input signal over 100mv pk-pk can
be used as an input.

Mode #2: Multiplexed mode

The Ch #1 is sub-divided as before. The clock input on the Ch. #2 is also sub-divided.
Each sub-octave output from divider #2 is used to gate the corresponding sub-octave
from Ch. 1 to the mixer. Therefore, the 4 suboctaves from Ch. 1 are gated in a 4 bit
binary pattern at the rate of Ch. #2.

What does this sound like? Well, If Ch. #2 is slow, then you hear a 16 "note" sequence
that repeats. As the frequency of Ch. #2 is increased (into the audio region) then you hear
all kinds of bizarre pulse animations, Very slight changes on the relative frequencies of the inputs
can cause large timbre shifts at the output. It can sound like a dirgidoo (sp?), and once I
got the "big chord" sound at the end of the THX logo in the movies.

So know I will start pcb layout and front panel fabrication. So, in about 3-4 weeks the kit will be ready
to ship.

Also, the VC dual 2:1 audio switch will be breadboarded over the weekend and ready to ship at about
the same time.

If anyone wants a 'real-time' demo (me twiddling knobs over the phone) call me at 888-818-MOTM.

Paul Schreiber
Synthesis Technology