Anyone ever tried Spectral amps with non-Spectral

I've owned Spectral amps and preamps for a long time now, but never attempted to pair up a Spectral amp with anything other than a Spectral preamp. I know that Spectral says that their amps need to be mated with their preamps and cables, otherwise damage to the amp may occur. I'm wondering whether or not this is actually true or is it just some marketing ploy. Has anyone else tried some other combination, whether it be tube or solid state? If so, what have you tried and what results have you experienced.
It all depends on which amps and which preamps.
I regularly mix and match my Spectral DMC-10,DMA50(2),
DMA200, with my ARC SP8 and ARC D115. No problems
at all. And it is fun to listen to the differences in
Some of the Spectral amps have very low input impedance (10K) and make most tube preamps angry.....They have an amp that has 100K input impedance, but the gain is only about 22db as opposed to the standard 28db, but their preamp has the extra 6db of gain to make up for it......Spectral just doesn't seem to believe in convention........
It took me a while to construct an all Spectral system. As a result, I spent a long time listening to Spectral with other equipment. I don't think Spectral plays very well with others. With other equipment, I often got the feeling that Spectral components were cold sounding. When I got to an all Spectral system, the sound suddenly became warm, smooth, transparent and relaxed. Now I can see why they only recommend their components within the context of an all Spectral system.
i have listened to Spectral with ARC preamps. At this pointy I really don't remember if the were the tubed variety. I was very impressed with the sound that had a more natural character than obtainable with spectral alone. There are cabling problems thoough that are surmountable. It just takes some effort that I am too busy to tackle.