Another motivation was that I wanted to offer guitarists, bassists and other musicians a compressor that was a genuine improvement over the numerous boutique stompbox compressors on the market, which were either exact copies or variations on the Japanese CA3080 transconductance op amp Ross design. Being a tube anorak, I’d already been doing my homework on vintage compressors/levelling amplifiers and had an idea in mind for creating something exceptional, unique and very special. I was determined that the Effectrode compressor should incorporate several of the essential elements found in a real studio compressor, including a ‘proper’ control side-chain, optical attenuator and all-tube signal path, a signal path that would utilise pro-audio grade components throughout, including polyester coupling capacitors, precision metal-film resistors and a triode vacuum tube.
Only one tube was required for the design and this led me to consider utilising a N.O.S. mil-spec subminiature tube to make the pedal as compact and robust as possible. These little tubes were originally designed for use in guided missile systems in WWII and their reliability and audio performance are outrageous—they just don’t make tubes like this anymore.
So, I began an outline detail for my own circuit design from the ground up, taking the classic LA-2A studio compressor as my inspiration. I recollect visiting the APRS (The Association of Professional Recording Services) show in 1994 whilst working at BSS Audio, and checking out Universal Audio’s replica of the Teletronix model LA-2A compressor at one of the exhibitor booths. This compressor processed music material with a light touch, wrapping the signal in velvet—a beautifully smooth and rich tone that was full of depth—it was impossible to get an unusable or bad sound from it. The front panel was pleasingly minimalist, straight-forward and uncluttered, with just two large ‘bakelite’ knobs labelled ‘Peak Reduction’ and ‘Gain’ and a big, bold analogue VU meter. This was the antithesis of BSS gear with it’s hi-tech look and densely populated front panels, which appear formidable, intimidating even, looking equally at home on the USS Enterprise. Two lessons learned: keep it simple and make it sound nice.
So there are just two controls on the PC-2A front panel—‘Peak Reduction’ and ‘Gain’. It’s the opinion of this designer (and guitarist) that controls for ‘attack’, ‘release’, ‘knee’, etc are more appropriate for studio compressors where an engineer may want to tailor these parameters to use the compressor for use with different instruments or for different applications. Adding too much flexibility to a guitar compressor, or any guitar effect for that matter, can be a bad thing—there are some places you just don’t want to go as they will lead you to ‘the dark side…’. For example, fast attack and release times can lead to ‘pumping’ where the compressor sounds distorted because it’s attempting to track the envelope of the input signal. In extreme cases this sounds like clipping—but not nice tube clipping distortion. It sounds terrible.