Aphex Dominator – Hardware Setup

Aphex Dominator II Model 720

The Aphex Dominator is a powerful tool but, at times, it’s not obvious what it’s doing or why. To appreciate it properly you need to patch it into an established signal chain, align it to the peak level you’re working to then set levels to get the required degree of limiting

This guide was written to help setup a Dominator in a podcast / broadcast chain but much of the detail is applicable in other setups

  1. RTFM
  2. Establish the peak level you want in your signal chain
  3. Put the Dominator in the chain & set levels approximately
  4. Set the EQ and density at midpoint >0<
  5. Set the release slightly above midway
  6. Turn the coarse limit control all the way clockwise
  7. Set the fine limit control to the midpoint >0<
  8. Set the range switch at zero (red led lit)
  9. Check for unity gain with the input gain at >0<
  10. Adjust input & output gains on the audio interface to set operating level
  11. Wind the coarse limit setting back so it just lights on program peaks
  12. Turn it one click clockwise so it doesn’t limit
  13. Use the fine limit control to get a nice threshold for limiting
  14. Increase the input level till you see gain reduction (GR) on the meter and hear lots of limiting
  15. Shorten the release time till it sounds good on your program material (see notes below)
  16. Experiment with the density & EQ controls with a bit of GR going on
  17. Back off the input level to reduce GR to a sensible level or till it sounds good to you
  18. Verify that the limited max output level ties in with the level required. If it’s out, rejig DAW input & output gains accordingly
  19. Check for unity gain with no GR, adjust input & output gains accordingly


  • Release time is really critical
  • Release & density make a big difference to the sound
  • The density control balances the contribution of the LF and HF signals to the limiting. With the control in the >0< position the bands are balanced
  • When misused the spectral balance can change quite dramatically
  • LF & HF band controls allow equalisation of the signal
  • There are switches for the turnover frequency of each section
  • Every control interacts and it takes a while to get the best out of it
  • You can make it super transparent or make it pump quite a bit
  • If in doubt back off the input level till GR is sensible
  • Turning the release clockwise makes release time shorter – the opposite of every other limiter ever made
  • Did I mention that release time is really critical?



The Dolby Trick – Hardware Setup

I had an enquiry recently about how to setup a 361 to perform “The Dolby Trick”. This is the basic setup:

Audio routing

  • DAW (effects send, bus, etc) —> audio interface —> Dolby “line in”
  • Dolby “to rec” output —> audio interface —> DAW channel line in

Send the signal to the Dolby & record the output. You’ll need to compensate for the audio interface latency

Dolby 361 back panel



 Hardware setup

  • Set NR in and Rec on (white & red buttons pushed in)
Dolby 361 with Modified Cat 22 Dolby Trick Card

Dolby 361 front panel


If you’re using a standard Cat.22 Dolby A card the output of the 361 will be the encoded signal – ie the original signal plus the processing. This means balancing the effect will take a bit of juggling with levels to get the effect you want

For a deeper effect & easier use a modified Cat.22 is a useful tool

How it works

As you reduce the level going into the Dolby the effect will increase. Dolby A encoding uses a multiband expander so more level = less effect, the inverse of a compressor, and the inverse of the decode process. For the Dolby Trick there is no decode process, just encoding

The NR in / out switch should give an obvious effect if you monitor the return signal. If you hear no effect, reduce the level into the Dolby


Dolby A passes the audio signal through a four-band compander. A sidechain determines the level of encoding for each band. In the encode process the sidechain-generated signal is summed with the audio, to create the encoded signal, and recorded to tape. On playback the sidechain recreates the encoded signal and subtracts it, decoding the signal

As a compander, Dolby A raises low-level signals during recording and lowers them again on playback. This has the effect of reducing tape noise by the same amount. There’s a lot of subtlety in the details – in the way the bands are chosen, the amount of expansion & compression and how these are optimised for maximum perceived effect and minimum artefacts


The 361 (and earlier 360) are hardware interfaces with no audio electronics but with input & output transformers. They have the power supply and switching to route audio to and from the Cat.22

The Cat.22 has audio electronics, input & output stages, sidechain and four bands of processing on one card. It’s all Class A, transistor-based circuitry

The separation of audio path and support hardware was a highly significant move. It meant Cat.22 noise reduction cards could be used in other hardware interfaces such as the M16 & M8 multitrack units and film playback systems. It also allowed the next generations of noise reduction, Dolby SR, to use existing interfaces

Ray Dolby was a clever guy, a true audio pioneer

Rhythm Roulette


My latest obsession: Rhythm Roulette. DJs & Producers take three records – or CDs – and chop them to make a beat. The level of talent is amazing – here 9th Wonder shows us how it’s done

Leon Theremin

Robert Moog, Roger Linn, Dave Smith, Don Buchla, Tom Oberheim, John Chowning, Leon Theremin, Olga Theremin

Robert Moog, Roger Linn, Dave Smith, Don Buchla, Tom Oberheim, John Chowning, Leon Theremin & Olga Theremin at Stanford University’s centennial celebration, September 1991

Leon Theremin was born on 15th August 1896. In this photo Theremin is surrounded by the most influential synthesiser designers & inventors of the last hundred years


Photo © Bob Moog Foundation Archive

What has Roland ever done for us?

Whilst writing the description of a Roland delay line, I thought about the various devices they’ve produced down the years. It’s a long list, littered with products almost every musician knows: TR-808 – is there anyone in the world who hasn’t heard one? RE-201 Space Echo – one of the hottest vintage items around. SH-101, JX-8P, D50 – the list is long & glorious

So, here’s my abridged list of “What has Roland ever done for us?”

RE-201 Space Echo

JC-120 Amplifier
Boss CE-1 Chorus

Roland System 100 synthesiser
Roland System 700 synthesiser

Roland GR-500 Guitar synthesiser
Roland MC-8 Microcomposer Sequencer

Roland CR-78 Drum Machine
Roland Jupiter-4 synthesiser

Roland Dimension D
Roland VP-330 Vocoder Plus
Roland System 100M modular synthesiser

Roland TR-808

Roland Jupiter-8
Roland MC-4
Roland SDE-2000 (first digital effects unit)
Roland TB-303
Roland TR-606

Roland SH-101
Roland Juno-6
Roland Juno-60

Roland TR-909

Roland MKS30 rack synth (version of the JX-3P)
Roland MKS-80 rack synth “Super Jupiter”
Roland JX-8P
Roland TR-707
Roland TR-727
Roland MPU-401 PC Midi interface

Roland MKS7 rack synth
Roland Alpha Juno
Roland Octapad

Roland MKS-70 rack synth (version of the JX-10)
Roland MKS-50 rack synth (version of a Juno)

Roland D50
Roland D550 rack synth (version of the D50)
Roland MT32 synth module


Roland JV880 rack synth (version of a JV-80)
SR-JV Expansion Boards

Roland JV-1080 rack synth “Super JV”

Roland JV-2080 rack synth

Herbie Hancock & Quincy Jones, Fairlight CMI

Quincy Jones hanging out with Herbie Hancock as he’s jamming with the Fairlight II. The Fairlight was an 8-Bit sampler with twin 8″ floppy drives. No mouse, just a light pen to use with the green screen. Vintage gear watchers will spot the Fender Rhodes, JBL monitors and what looks like a Commodore computer, probably for an editing program. Circa 1985