It's really amazing how many things effect the sound of a compressor, how many different parts of the circuit make a compressor sound like it does. From component choice to board layout to timing to compressor circuitry to output device, they all work together to make a compressor sound just the way it does.
A few points really stand out. Number one is probably the timing of the compressor circuit. How you control the timing of how fast the unit reacts and how it reacts in the side chain is of primary importance. A 'text-book' compressor has a very predictable scale, a linear ratio that simply compresses a signal in a very straightforward fashion. How we have designed our compressors is actually much more complex than that. If you notice on the DCL-200 for example, you see that the timing doesn't say "0.01mS" as the fastest attack time, or "2S" as the slowest release time, they are just simply written on a scale from 1-10. And there is no "ratio" control, there is something called "slope" instead.. This is all because of the timing circuitry inside the DCL-200 (same for TLA-100A and TLA-50 although the methods and signal path are much different). Our compressors react to the incoming signal, following the incredibly complex changes in voltage that even a simple musical line becomes in the electrical medium. When the TLA-100A is set to Fast, or the DCL-200's attack setting is set to fast, this selects a range from which the compression circuitry can work but it does not force any particular timing on the signal. Let's choose the signal coming from a bass guitar. That initial attack from the finger on the string is very fast and our compressors would react to that very quickly in fast mode (if the gain from that was high enough), but the rest of the signal, the body and much higher energy part, is legato and doesn't need the same treatment. Our compressors are designed to react musically, WITH the signal, not against it, giving a much more pleasing compressed sound that is natural while still reigning in the dynamic range. This is also why it's really incredibly difficult to 'copy' our compressors in software, these voltage fluctuations happen constantly so a processor would have to work very hard to handle it.
Another part that helps our compressors have 'the Summit sound' is of course the signal path we have chosen. Using the vacuum tubes the way we do with full plate voltage and where it is in the circuit utilizes the best part of the tube, the warmth and character associated with the even-order harmonics, without the high frequency fall-out and low-mid muddiness of starved plate circuits and forcing a tube to do more then it was intended. The choice of the Jensen 990 op amps at the output was another key choice for the DCL-200 and TLA-100A; they have incredible high frequency retention so those harmonics pass through with complete clarity and no feeling of shrillness. High voltage rails, solid power supply, and the time tested component choices we make all combine to make Summit Audio compressors really stand out.
With more than 20 years of experience making compressors, Summit Audio has the experience,history, and passion to make the best sounding compressors on the planet.