BLACET Frac Synth with 10 Modules and Case

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Blacet Research MD2600/2650 Module Tutorial video upload by jblacetIII

From the listing:

"SCANNER

This selects three inputs via a control voltage and sends it to the output. Musically interesting, and you can see the YouTube video on how this one's designed."

via this auction

Pics of the inside below.

"BLACET Research Frac Synth. Built by me from kits starting around 2015, it includes...

VCO (x2)

Calibrated in February, and they track quite nicely. Offers the usual sine, triangle and sawtooth waves, along with PWM and a 'VC WAVE' output. This is a clever circuit with back-to-back LEDs to let a control voltage change the wave from a triangle to a funky square wave. The FM input is also versatile with switchable linear/exponential tracking and AC/DC coupling. Also very handy to have two CV inputs.

FREQUENCY DIVIDER

This one does just what it says. It has two input channels and can be controlled at the front panel or a VC divider input. The channel B divisor is also switchable between 1-32 or 1- 32K. The lag controls the harmonic output, and the XOR output adds a ring modulator effect.

ADSR

This one is called the event generator. Along with manual control, there are CV inputs for ADSR. The Time Base has a range of 2500:1 allowing events from 600uS to 4 hours. Normal and inverted outputs ave available.

VCA

Does what it's supposed to do, with four inputs and a master VCA that allows inputs of both audio and control voltages. The shape control allows exponential or linear response of the CV inputs along with a panning function.

VCF

The 'Filthy Filtre' is very flexible and has manual control and CV inputs for frequency, resonance and an additional modulation input that can be routed. The Mode CV allows the filter type to be voltage controlled and there are output jacks for LP/BP/HP and a Notch filter. The 'Filthy' is interesting... The output stage is throttled back in the X10 position, and X100 adds the extra punch. Very musical!

MIXER

A five-input mixer with Pan and Level controls and mono or stereo outputs along with a master level control and a jack for headphones.

LFO

The usual triangle, square, and sine wave outputs are here along with a pair that go 0-10V that would be useful with the pan function. Initial rate and a CV control input allow modulation of the rate, and even the waveshape. An unusual surprise is the Range DIP switch on the PC board. Low range allows output of 80 seconds to 350 Hz and the high range is 15 minutes to 32 Hz!

BAR GRAPH

This is so useful that every analog synth needs one.

SCANNER

This selects three inputs via a control voltage and sends it to the output. Musically interesting, and you can see the YouTube video on how this one's designed.


Also includes the rack-mount frame and power supply with distribution board, all documentation and schematics, and a bundle of cables.

All of these modules were hand-built by me and I'm a far better technician than a musician. In my youth I learned electronics by reading books by Don Lancaster and Forrest Mimms. John Balcet did an excellent job of design, what we used to call 'elegant'. Check out the VCO... Increased stability due to matched transistors in a common case with the temperature-compensating resistor right on top."