The E-Series EQ Module features two EQs, one found on editions of the console produced between 1981 and 1989. Each EQ has unique response curves and tonal character. Historically, the type of EQ fitted in an individual console was distinguished by the colours used on the LF knob caps, so the two flavours have become known as the 'Brown' and 'Black' EQs. On the E Series EQ Module, you can switch between two different flavours of EQ that have been loved by generations of professional producers. Features

• Each EQ has unique response curves and tonal character
• Switch two different flavours of EQ 

Key Specifications

• Format: API-500 series compatible module.
• Model number: 729720X2 (also listed as 729720X1 in some spec-pages)
• UPC: 878076001548
• Circuitry: SSL 4000 E Series “611 design” channel EQ reproduced.
• Dual-flavour EQ switching: “Brown-02” and “Black-242” circuits.
• Bands:
• • HF shelving with optional bell curve
  • HMF (parametric) with Q control
  • LMF (parametric) with Q control
  • LF shelving with optional bell curve
• Input/Output nominal level: +4 dBu (typical for 500-series modules)
• Build: Single-slot 500-series module—fits standard lunch-box or rack.

Why This Module Matters / Use-Cases

• The tonal signature of the SSL 4000 E console EQ is deeply embedded in the history of popular music and professional recording. This module gives you that heritage in a compact, modern 500-series form.
• The ability to switch between “Brown” and “Black” EQ variants means you get two distinct tonal characters in one module—ideal for broad tracking use or surgical mixing.
• With full parametric mids and bell-options on shelving bands, you have both musical breadth and precision control for drums, vocals, guitars, mix-bus duties, or mastering chains.
• The 500-series format means this integrates seamlessly into lunch-box or rack-mount systems—great for mobile rigs, hybrid studios, or professional installations.