This analog OTA guitar compressor basically became a blueprint for creating classics such as Dynacomp*, Keeley*, and many other popular units. Ross* is probably one of the most famous pedals of this type on the market. It has a warm, analog tone, amazing sustain and organic, tube sound which separates it by the mile from uncannily flawless (and deprived of personality) VCA compressors. It is easy to use and gets its primarily job done just the way it is supposed to – mutes the loud sounds and boosts the quiet ones. We can regulate its sensitivity with the SUSTAIN knob, and it can boost sounds up to 40dB, with very low noise levels. By enhancing the sustain it makes playing easier and the sounds become clearer and receive some of that signature analog warmth. It is easy to achieve great dynamics which sound like guitars recorded in a professional studio. This always-popular unit, which is on par with its rack tube equivalents, has frequently been named the best compressor ever and became a canonical standard in the history of music production.
In this construction, I’ve decided to use a modification from Keeley*. There are two additional pots – ATTACK and CLIPPING which regulate the speed of compression (it comes useful if you want to emphasize separate notes during speed-playing) and adjust the signal to match our guitar pickups. Since the second one is used only from time to time, it is placed inside the stompbox. To make this compressor I have used the original (and hard to find) vintage CA3080 chip. The whole of the audio path is built with high-quality tantalum capacitors.
- Requires stabilized 9V power supply (2.1/5.5 plug with “plus on the outside”)
- Can be used with a voltage higher than 9V, but not exceeding 18V.
- Under the cover, there is a pot which can be used to set the clipping parameter.
?The level of guitarist’s experience on a five-point scale. The higher the level, the more skill the pedal requires.