This is from one of Spectral's dealers:
"Note: Whereas other Spectral Audio components (
i.e. their preamplifiers and digital source components) may be used with any other brand of equipment, Spectral mandates that their non-Universal amplifiers be driven by a Spectral preamplifier to ensure reliable operation. Spectral Universal amplifiers however may be driven directly by any brand of preamp, D-A, or surround sound processor. In addition, S
pectral amplifiers need to be used in conjunction with the proper Spectral-approved MIT interconnects and speaker cables. These usage guidelines are now a condition of Spectral's warranty on their amplifiers. There are several reasons for these guidelines:
- Because of their wide bandwidth, Spectral amplifiers can amplify high frequency signals in the MHz range at massive power levels. Therefore radio frequency noise must be kept out of the amplifier. The MIT interconnects contain RF protection, and Spectral preamplifiers are stable at these high frequencies.
- Unlike most all solid state preamps, Spectral preamplifiers are true discrete designs, are DC coupled, and can output the high current that the (non-Universal) Spectral power amps are designed to be driven by. Other brands of preamplifiers often use integrated circuits or other devices which may not be able to drive the amplifier properly. It is interesting to know that IC's (integrated circuits) simply cannot provide for high current output in a preamp design which utilizes them. Whereas a fully discrete Spectral preamp—fully discrete meaning no IC's in the signal path—can provide on the order of 1 ampere of output current per channel!
- As part of their stability design, Spectral amplifiers are designed to be used with the type of output network found in the Spectral-approved MIT speaker cables. (You might be interested to know Spectral has found that by placing this network close to the load, i.e. the speaker, they can achieve superior results.)
What will happen if you don't follow these guidelines? Well, it's a probability thing. You may not encounter any problems—or you may encounter premature failure of some components in the amplifier. Or (worst case) your amplifier may suffer severe RF problems, and you will have to pay to have all the output devices replaced (which is expensive). Therefore, we highly recommend that you follow Spectral's operational and warranty guidelines for both peace of mind as well as highest performance and fidelity."
When I owned Spectral gear I remember the warning about using anything other than the approved MIT cable could void warranty in the manual. The dealer also made that point clear. My takeaway: use the MIT cables, if not, any damage that may be caused by not following Spectral's guidelines was on me.