Remote Controlled Analogue Summing

Designed for the DAW user that seeks the legendary big sound of an SSL console while retaining the convenience of working in the box, Sigma δelta is a unique rack mounting SuperAnalogueTM mixer with full synchronised control via the Sigma Remote Control Application and Delta-Control DAW plug-ins.


Sigma δelta seamlessly brings the analogue joy of mixing on an SSL console into your DAW dominated workflow. Using MDAC technology unique to SSL, Sigma takes the SuperAnalogueTM mix buss from SSL's Duality and AWS consoles and delivers it in a 2U rack design, with complete remote control of the analogue signal path, using either a hardware control surface and/or a simple Remote Control Application, and/or directly from your DAW using the innovative SSL δelta-Control (δ-Ctrl) plug-in. Now anyone who can drive a DAW can mix on an SSL.


Consistent feedback from the world's leading producers demonstrates that analogue summing still brings a record together in a special way that no emulation plug-in can match. Sigma δelta and SSL's no-compromise approach to designing audio circuits, delivers summing with an extended low-end frequency response, wide stereo imaging, clarity, depth and detail.


When it comes to sonic tone and character many leading engineers state that a significant part of their 'sound' is the magic that happens when you drive the analogue mix buss of a console a little too hard...that delicate cohesive distortion only a pushed analogue mix buss brings their mixes. This is exactly the case with Sigma. It is at its best when pushed to that "sweet spot", to the point where it yields that extra sonic dimension which has always been part of the legendary SSL sound.


Sigma δelta combines its true analogue tone and depth with complete integration into a DAW dominated workflow. In today's commercial environment, fast turnaround of productions, with multiple mix tweaks and revisions, engineers and producers depend upon instant recall of all their settings. Sigma meets this demand. As Sigma's levels are driven from your DAW, the mix recalls instantly upon session load. Furthermore, every setting on Sigma itself (mix buss routing, monitoring section and settings) can be saved and recalled at the click of a button.

SSL Sigma ∂: Remote controlled mix engine Now With Delta Control

SKU: 729760X1

Physical *

  • Depth 320mm / 12.75" casing only
  • Height 89mm / 3.5" (2 RU)
  • Width 435mm / 17" casing only
  • 482mm / 19" inc’ rack ears
  • Weight 5kg / 11 pounds
  • Power < 60 Watts
  • Boxed size 20" x 22.5" x 11"
  • Boxed weight 10kg / 22 pounds
  • * All values are approximate


  • Temperature Operating: +5 to 30 deg. C
  • Non-operating: –20 to 50 deg. C
  • Max. gradient: 15 deg. C/hour
  • Relative Operating: 20 to 80%
  • Humidity Non-operating: 5 to 90%
  • Max. wet bulb: 29 deg. C
  • (non-condensing)
  • Vibration Operating: < 0.2 G (3 – 100Hz)
  • Non-operating: < 0.4 G (3 – 100Hz)
  • Shock Operating: < 2 G (10ms max.)
  • Non-operating: < 10 G (10ms max.)
  • Altitude Operating: 0 to 3000m
  • (above sea level) Non-operating: 0 to 12000m


  • Power Supply IEC320 3-pin connector, 100 – 240 Vac, 50 – 60 Hz
  • DC Power 2mm DC power jack, +12V, < 3A
  • Analogue I/O 25-pin D-type socket, balanced, Zin > 10kΩ, Zo ≈ 100Ω
  • 3-pin XLR-M, balanced, Zo ≈ 100Ω
  • Headphones Stereo 1/4" jack socket, Zo ≈ 75Ω
  • Footswitch Stereo 1/4" jack socket (1 circuit)
  • iJack Stereo 3.5mm jack socket, Zi ≈ 10k
  • Network 8P8c modular connector; ‘RJ-45’ type (100bT, Cat5)
  • USB 1 x type-B chassis socket (SSL diagnostic use only)


  • Maximum I/O Level +18dBu, +22dBu or 24dBu
  • Frequency response 20Hz – 40kHz ±0.3dB
  • THD + N < 0.025% (20Hz – 20kHz)
  • Noise
  • CHIP to CHOP < –83dBu @ +24dBu (20Hz – 20kHz)
  • CHIP to MIX A < –75dBu @ +24dBu (20Hz – 20kHz)
  • (stereo, all channels routed)

© 2020 by massmusiK