Ridge Farm Boiler

Ridge Farm Studios began making equipment in 1995, and have followed up their Gas Cooker DI box with the Boiler, a two‑channel compressor. Paul White assesses its no‑frills approach to the art of the big squeeze.

A few years back, in SOS June '95, I reviewed the first commercial product from Ridge Farm studios, the Gas Cooker tube DI box. It looked like a piece of Ministry of Defence equipment with its 1930s metal case and big Bakelite knobs, but it worked really well. Now they've come up with a different product with an equally distinctive name — the Boiler. Housed in a cool turquoise 1U rack box, the Boiler is a two‑channel, VCA‑based compressor with deceptively few controls, no side‑chain insert points, no stereo linking and no cosmetic similarity to the Gas Cooker whatsoever.

The rear‑panel inputs and outputs are all on balanced XLRs — there are no quarter‑inch jack concessions to home studio users here. Things are almost as inscrutable on the front panel with just two knobs per channel, one to set the input gain and the other the threshold. A 10‑section LED meter monitors the absolute signal level — it's not switchable to read gain reduction as those of almost all other compressors are — and even the usual attack and release controls have been replaced by a pair of simple Fast/Slow switches. A further toggle switch bypasses the channel. None of the switches, other than the mains switch, has a status LED and none of the knobs are calibrated — nor do they have dial markings of any kind for that matter. This is most definitely a 'twiddle it until it sounds nice' kind of box, so the lack of calibration is probably a deliberate design statement rather than an omission of any sort.

The Boiler came with no documentation, so all judgement must therefore be purely subjective — the only clue I have is anecdotal insomuch as I'm told this is a compressor designed to be heard working. It's not intended to be a transparent gain‑control tool.

Using The Boiler

After a few minutes playing with the controls, I figured out what was happening. The input gain does exactly as it says and controls the amplitude of the compressor input. Threshold sets the level at which compression takes place, and if you watch the meter, it's pretty obvious where this is as loud sounds overshoot briefly, then drop back so that one particular LED on the meter is glowing. As you adjust the threshold, the signal level is pegged at a different point on the meter, and because the meter is calibrated in dBs, you can set your nominal output level by feeding a loud, sustained sound into the input, then adjusting the threshold until the desired meter reading is obtained. I say nominal because the fact that some overshoot occurs, even on the fast attack setting, means you have to leave some headroom when feeding digital equipment.

Compression With Attitude

To control the degree of compression, you first set the threshold according to the level you actually want to get out of the compressor, then use the Input control to force the input signal up against the compressor threshold. The more you turn up the input level, the more compression you get. As intimated earlier, the compression is pretty unsubtle in a rock and roll kind of way, but it works very well on an artistic level. It sounds good on bass, drums, voice, guitar — you name it, but unless you really back off the controls, you always get compression with attitude.

Because there's no gain‑reduction meter, you have to set the amount of compression entirely by ear, and though this isn't difficult, I would still have preferred a meter if only because the amount of compression applied has a bearing on the signal‑to‑noise ratio. There's no stereo linking facility, but after using the compressor a while, gained the impression that mix compression wouldn't be its primary application in any case.

Ultimately, this is a nicely quirky compressor with a distinctly vintage sound. The Boiler won't be to everybody's taste, but if you like the sound of a compressor that rules by brute force rather than gentle persuasion, you have to check this out.