AS 1973 FET Compressor

Updated on 16 February 2026. Built it in v4.0 and a first pass at this device. See notes below. Enjoy! 

Here is something new - I like the sound of the Drawmer mastering compressor and I found a manual for the hardware version of the 1973 FET Three-Band Stereo Compressor and thought I'd have a go at making my own version as a Bitwig Studio preset. My approach was to replicate the programme driven ratio response curves for each band and to put a low level of saturation on the each band that is applied as the gain is brought up. Earlier versions had lots of issues and I've reworked the internal wiring so that the thresholds are more natural feeling and sound much, much better.

Recommended usage:

1. Start with the preset as shown below. In the default state there should be no changes to the signal.

2. Adjust the Thresholds for each band to suit your taste. Try the Mute option to silence the other bands to isolate the frequencies you are interested in with the Low and High X Over controls.

3. As you adjust the Thresholds downwards a makeup gain is applied in the Dynamics device.

4. Adjust the Attack and Release to fit your goals. These are stepped and have a reduced range to mimic the Drawmer hardware unit.

5. Apply Gain to each band as needed. Saturation is gradually added as you push the gain upwards.

6. Big will mix some of the low band back (by reducing the sidechain signal response for the Low Dynamics device) and Air will do the same for the upper range (boosting the gain slightly).

Each band has a Dynamics Device with a Sidechain Modulator that modulates the Hi Ratio and Hi Knee, and this is passed into a Saturator Device. The High band has a FX Layer with the devices as the other bands and the FX Layer Gain is used to add the Air into the signal when the Air button is active.

Is it the same as an expensive plug in that requires iLok or some other licensing software? No. Is it the same as the hardware model? Most likely not at all since I've not had the pleasure to operate one. Does it do something that makes me happy? Very much yes with version 1.2! Maybe you'll enjoy it too - grab a copy from the link below.

AS 1973 FET Comp v1.2 (Bitwig v4.0+ fxGrid Preset) 

Warning: can produce frequencies and volumes which may damage hearing, audio gear and speaker coils. Be kind to your ears and gear.