Aphex Compellor 300 #8


In stock


Aphex carved a niche in the signal processing market, first with the Aural Exciter, then with a series of superb levelling / compressor units including the Compellor. These are super-transparent units with no discernible “sound” and they’re built to the highest standards

At the heart of the Compellor is a VCA controlled by a sophisticated sidechain. Proprietary Aphex algorithms control gain reduction to give simultaneous levelling & compression. Compression uses short time constants to work quickly & inaudibly and levelling operates over longer periods to maintain average levels. The two strategies keep peaks under control whilst maintaining a consistent output level

Compellor controls are unlike ordinary compressors. The Drive and Output controls are detented and allow the amount of processing to be varied while keeping the output at the same level. Process Balance moves the system between Levelling and Compression and there’s a slow / fast rate switch to change time constants. The two processes can be stereo linked. There’s a stereo enhancer and predictably, from a broadcast-oriented company like Aphex, the Compellor has perfect mono compatibility with no odd phase changes

In a studio setting the Compellor is confusing at first. It can be difficult to hear it working but a quick flick of the process in / out switches makes you realise what it’s doing. It’s not a “grabby” unit that imposes its own sound on the signal, it’s more of a “glue” compressor, better suited to buss compression than drum tracks. On a bluesy song with a very sparse intro, I found the Compellor would pull things together nicely without killing everything when the drums kicked in. It’s not an instant attitude box like a Valley People Dynamite, or punchy like an SSL buss compressor, but it’s a great tool to glue things together. I’d like to try it in series with an SSL compressor

Like all these Aphex units, the Compellor is beautifully-built and has a quality feel. The internal layout is well-organised and components are high quality. These are not built down to a price like 99% of outboard gear

This is a Compellor 300, one of the earlier versions. In excellent condition with minimal marks. Tested & working 100%. Photos show the Compellor for sale

Inputs and outputs are electronically balanced on XLRs. Mains is switchable 110 / 220 Volts and uses a standard IEC mains plug. UK or Euro Schuko power lead supplied on request
Standard 19" 1U device suitable for all 19" racks.  100-240 Volt with voltage selector and  standard IEC power socket

PDF Owners manual

Owner's manual

Gearslutz (later Model 320A)


In excellent used condition. Tested & working 100%. Photos show the Compellor for sale