Dimensions
3 U
Current Draw
65 mA +15V
50 mA -15V
Price
$435 Price in €

This Module is currently available.

Two cross coupled oscillators & a filter to produce a compact sonic surprise source.

The Chirper 3FW is a distillation of the original Red Chirper boiled down & modified to a compact module version. The pre-arranged configuration of two cross-coupled voltage-controlled oscillators and one voltage-controlled filter seems like a simple setup but it hides a rich world of sonic surprises – even more so when combined with the Chirper Expander!

The Block Diagram shows how the Chirper is put together:

the two Oscs are identical, with wide range (c.0.1Hz to 40kHz) and sweepable from Triangle to Square.
each Osc has a 1V/Oct input, an External Modulation input with polarity switch and depth control, plus an Internal Modulation depth control sourced from the other oscillator.
in addition, an in-phase squarewave is generated for each Osc (mainly for use with the Expander) – the Square wave can be selected via a jumper on the rear as Norm(al) or InPhase.
the State-Variable Filter can be fed from Osc1 or an external signal (typical +/-5V) and resonance goes up to self-oscillation. The output is switchable from LowPass to either Band or High Pass (selectable on the rear via jumper). The filter has an External Modulation input with polarity switch & depth control (approx 1V/Oct at full depth), along with Internal Modulation from Osc2.
The design is centred around a single 2164 Quad-VCA chip (obviously with much supporting circuitry!) – one section is used for each VCO and the other two for the VCF. Note that the 1V/Oct response of the Oscs & Filter are only quite accurate – fine for tracking over a few octaves, but not temperature compensated nor as accurate as the more advanced VCO modules. The overall design aim is more at surprise than being a well-pitched synth!

https://www.bugbrand.co.uk/product/chirper-3fw/


submitted Mar 14th 2023, 22:01 by wiggler111721 | last Change Apr 17th, 04:24 by DrewD

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