You know how when you hit a note on your guitar when it's plugged into a tube amp and the gain is set right on the verge of break-up, and there's kind of a "spongy" type compressed transient attack you get from the rectifier tube's drop in voltage and recovery? It's a very smooth and "musical" thing that happens - solid state gear doesn't really do it, and a lot of modeling programs out there don't get it either.
DSM is an exclusive IK Multimedia technology developed to accurately emulate the non-linear interactions between components in an analog circuit. DSM™ was designed to increase the response realism and playability of critical analog circuit models. Musicians always felt digital emulations of high quality analog gear (such as tube driven guitar amplifiers) to be good but not completely satisfying because of the lack of certain "playability" and "musicality" qualities that only the real thing provides.
DSM gives special and unique results when applied to circuit emulations where the non-linearity is the main characteristic of the processor, such as in distortion, fuzz, overdrive stomp boxes, tube guitar preamplifiers and power amps, and analog compressors and limiters. The DSM™ working principle is based on a new approach never applied to DSP "analog modeling" until now. Analog circuits, especially Tube and Class-A discrete ones, are not dynamically-linear, but have been modeled this way by today's technology. An analog circuit's character is never constantly shaped but varies depending on lots of parameters, first and foremost the strength, frequency and harmonic content of the incoming signal.
DSM takes the next step. It continuously adapts the "shape" of the analog circuit instead of applying a static snapshot. By using more complex mathematical functions, a more articulated and musical response is possible, making DSM™ ideal for modeling tube preamps and tube power amps.
Traditional emulations are forced to a tradeoff between, for example, those kind of distortions that appear only when a 2x6L6 tube power amplifier is driven to its limit and the cleaner sound it has when it's driven normally.
DSM delivers a dynamic response that continuously morphs and "follows" the incoming signal; in other words, that follows the music.
This leads to an accuracy that cannot be found in any other modeling hardware or software today, respecting all the signal nuances exactly like a real analog circuit would do with a grade of realism and musicality never achieved before.