UBZR1 Noise Generator Module

Chelys Lyra


The Noise module serves two purposes:

Functional Description

The noise module uses a transistor operated in reverse mode above breakdown voltage with current limited.

The following opamp circuits filter for

Final amplification is done with an LM 13700 transconductance amplifier, which serves as a built-in VCA and provides for two separate current outputs, one for white/pink noise and one for pink/red noise. The former can be used in the audio path, the latter is available in the modulation matrix.

Performance Specs

‑ to be documented ‑

Schematics as SVG Files

Noise Block Schematics

Noise Generator Schematics

Noise Selection and VCAs Schematics

Noise Exp. Current Sources Schematics



In UBZR1, that latter two inputs are wired together outside of the Noise module board, because outputs #0 and #1 are not likely to be used at the same time.



Last change: 2024-01-11
© 2002-2023 Dr. Thomas Redelberger

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