Excellent point Tracy. I used to own an SP-6 and an SP-3 before that, as well as D-75 and D-51 power amps, and still have an LS-1 line stage (for my Stax ESL headphones, and the LS-1's "Mode" switch---Stereo/Reverse/Mono/Left/Right). ARC products are known to have somewhat high maintenance costs, a result of the high voltages the tubes are run at. That, plus, the power tubes are not fused---when a tube shorts, it often takes out at least a resistor, sometimes more of the surrounding circuit. They have even been known to burst into flames! And the amps circuits are traces on circuit boards, rather than point-to-point wired as are Music Reference amps. The ARC tubes sit in sockets built right into the boards, a very bad idea as the heat from the tubes scorch the boards over time. Rather than needing to replace the bad tube and it's fuse, ARC amps often require an actual repair when a tube fails. I would NEVER own another ARC power amp, I don't care how good it sounds. Roger Modjeski puts a fuse on every power tube in every one of his Music Reference amps, and runs them conservatively, the tubes lasting up to 10,000 hours. He also winds his own output transformers, and hand-builds every amp himself. And they are much more reasonably priced than ARC. Roger says he builds them to last a hundred---a hundred!---years. Heirloom products, highly recommended. Lately he has been designing lower output amps (single-ended, push-pull, triode, pentode, you name it), designed of course for higher sensitivity loudspeakers. They should be a match made in Heaven for Danny's designs!
