The 3630 has become a bit of a legend due to its unsubtlety, alleged poor sound quality and its capacity to provide vicious pumping compression
Do they sound bad? No – they sound like pretty much any other VCA-based compressor when they’re not working hard. Do they sound good? That depends on your definition of good
I found they are difficult to set up and very critical of threshold and attack times. Once set correctly they are very effective, and once set to pump like crazy they produce a wonderful squashed sound which is fantastic added to the original sound (aka parallel compression)
I’ve revisited the Alesis 3630 and concentrated on modifications that make the most significant difference. Late-model 3630s like these already have the THAT VCA chip, and I’ve shortened the compressor release time to allow more brutal compression at low release settings. I’ve also used much larger bipolar caps in the audio path, improving the bass response, and massively upgraded the power supply
In modified form the 3630 is like any other VCA compressor – sonically, almost totally dependent on the sidechain. If you choose short attack & release times and high ratios it’s possible to turn audio into shaped noise but, then again, often that’s the aim…
The secret with the 3630 is to ignore the front panel and tweak till it sounds good. Try it in Peak & Hard Knee using lower ratios and be careful with the threshold setting. Once gain reduction exceeds 6 dB or so you’ll begin to hear artefacts but there is a sweet spot where it sounds great
Alesis 3630 Compressor – Modified & Recapped
