MIT cables for Spectral amps ?

You may not do damage, but you might void the warranty. Harry Pearson used Nordost speaker cables on a pair of DMA- 360s and had fine results.
I think spectral worries about speaker damage if the megahertz range of the amp is not filtered by the MIT cables. something like that.

Just thought I'd throw my .02 on this. I used to own a DMC-20 and a pair of M80 monos.

My understanding was that the amps could be damaged when using non MIT cables and that Spectral was able to identify that this was the case when a repair was required and thus not honor the warrenty. Spectral is extremely particular about their equipment.

I would double check with the dealer such as Progressive in Columbus or Spectral themselves.

I have never been a big fan of the MIT cable. MIT on Spectral gear is something very special. I would encourage you to use this combination. Where is Detlof when you need him? Spectral and MIT is pure magic.
Where are you Detlof, I need some backup on this one.

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.