EM-301 | Twin Blackmer VCAs

St. Tropez is a dual-channel voltage-controlled amplifier built around the THAT2181A, a precision monolithic VCA derived from the Blackmer gain-control architecture. Its complementary dielectric-isolated transistor structure provides exceptional dynamic range, low distortion, and minimal control-voltage feedthrough, 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 selecting 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 operate independently, with passive summing available at the second channel's output. This arrangement accommodates dual VCA operation, parallel modulation, and layered amplitude control without requiring an external mixer.

The architecture is deliberately restrained: precise voltage-to-gain conversion, wide dynamic range, and minimal coloration. From conventional envelope-driven amplitude shaping to complex bipolar modulation and dynamically evolving control contours, St. Tropez approaches amplification as an exercise in precision rather than embellishment.

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.