MIT cables for Spectral amps ?

MIT cable is specified because it ensures that the amp will see a stable load at all operating points. The reactive charactaristics of the load can cause these wideband amps to become unstable (oscillating at above-hearing-range frequencies so you don't even know about it) until the amps' output devices fail. The MIT cable networks are parallel across the load, acting similar to a Zoebel network across the actual drivers, thus enhancing amplifier stability. I don't know how Spectral can determine what the failure mode was after the fact, but they definitely do know. Sometimes with certain combinations of speakers & cables you'll get lucky though. Up to you to determine if taking that risk is worthwhile.

I have a DMC-20 Series II with DMA-360s. Use the MIT, the best models you can afford. It's worth it.

Brulee and Bob Bundus are right . You will bring out the most of your Spectral gear in speed, transparency, pristine highs und tight bottom ends (sigh) with the MIT stuff, which otherwise has to be used with caution. Not so, I find, with the DMA 200, if it is the amp of 1987 vintage. If this is the case, there is no warranty to void. I've been using the Nordost stuff with them, without any problems and before that, Madrigal ICs and solid core Furukawa speaker cables since the late 1980s without any failures on the amp's part.