Looking at some rear panel photos that are available on the web, and at manuals that are available at the Sunfire website for what appear to be comparable later models, it appears that the 5A fuses (changed to 6A in later models) protect just the "current source" outputs, not the "voltage source" outputs.
My guess is that the 600W rating only applies to the voltage source outputs, and the CONTINUOUS output power capability of the current source outputs is far less (with the difference between the two outputs in terms of short-term (dynamic) power capability being much smaller). I suspect that the current source outputs are created by just putting the voltage source outputs through low value resistors having high power handling capability. The fuses are probably provided just to protect the resistors, with the voltage outputs being protected by circuitry.
So the 5A fuse rating, corresponding to 200W into 8 ohms, is probably understandable. The 10A main fuse does seem somewhat incongruous with the 600W/channel rating, as the 1200W AC input it would support (120V x 10A) would require that the amp be 100% efficient to output 2 x 600W continuously, which of course is not possible. Perhaps it's a design oversight, or perhaps the 600W continuous rating is a bit optimistic.
Regards,
-- Al
My guess is that the 600W rating only applies to the voltage source outputs, and the CONTINUOUS output power capability of the current source outputs is far less (with the difference between the two outputs in terms of short-term (dynamic) power capability being much smaller). I suspect that the current source outputs are created by just putting the voltage source outputs through low value resistors having high power handling capability. The fuses are probably provided just to protect the resistors, with the voltage outputs being protected by circuitry.
So the 5A fuse rating, corresponding to 200W into 8 ohms, is probably understandable. The 10A main fuse does seem somewhat incongruous with the 600W/channel rating, as the 1200W AC input it would support (120V x 10A) would require that the amp be 100% efficient to output 2 x 600W continuously, which of course is not possible. Perhaps it's a design oversight, or perhaps the 600W continuous rating is a bit optimistic.
Regards,
-- Al