EM-301 | Twin Blackmer VCAs

St. Tropez is a dual-channel voltage-controlled amplifier built around two independent THAT2181A precision monolithic VCAs, each derived from the Blackmer gain-control architecture. The devices employ complementary dielectric-isolated transistor structures, providing wide dynamic range, low distortion, and minimal control-voltage feedthrough while preserving signal integrity across a broad range of gain-control applications.

Each channel features independent bias and modulation-depth controls, together with a continuously variable response characteristic spanning exponential, linear, and logarithmic control laws. Rather than switching between fixed response curves, the control permits continuous interpolation, allowing the relationship between incoming control voltage and output amplitude to be shaped with precision.

Both channels maintain independent signal paths, with Channel I's output internally normalled to Channel II when the first output jack is unoccupied. This configuration combines both signals into a high-fidelity mix at Output II without requiring an external mixer. Inserting a cable into Output I breaks the normalled connection, restoring fully independent output operation.

The architecture is deliberately restrained: precise voltage-to-gain conversion, wide dynamic range, and minimal coloration. From conventional envelope-driven amplitude shaping to layered modulation and complex dynamic control, St. Tropez maintains a consistent emphasis on accurate gain behavior and transparency throughout the signal path.

SPECIFICATIONS

• Dual independent Blackmer-topology voltage-controlled amplifiers
• Precision THAT2181A monolithic VCA architecture
• Continuously variable exponential / linear / logarithmic response
• Independent bias and CV modulation-depth controls per channel
• Independent channel outputs with passive summing at Channel II
• Low distortion and control-voltage feedthrough
• Wide dynamic range and precision gain control

LA CIRCUITS, INC.

Official Website — https://circuits.audio
Instagram — https://instagram.com/lacircuits
Email — contact@circuits.audio

https://circuits.audio

• 36 mA +12V
• 36 mA -12V
• 0 mA 5V

This Module is currently available.