A different take on "headroom"
Hmm,
Well in the case of the Proton, it seems like we almost have a Hitachi class "G" variant of sorts, also kind of similar to Carvers original magnetic field (just similar). These are OK with me, since the extra headroom is built into the design for that purpose. Like so many amp specs taken alone however, I have a little different spin on this, instead of headroom, in a SS amp, I think of this spec as "sag" or "droop" and I also think that high numbers in this spec are not always great taken alone... I'm just going to guess, but if You look to the insanely esoteric like Krell(and others), some of their designs would spec out close to 0 dB of headroom. Whatever the amps circuitry is capable of on a peak, if it cant sustain it indefinitely, my opinion is that the power supply is short on gas. OdB headroom to me in a SS amp, means that the supply does not sag at all, and that is a design goal in my book, but impossible to achieve without regulation, which is overkill for an amp. Conversely, one could build a conventional SS amp with a really whimpy power transformer, but tried to make up for it with a little extra filter capacitance, and You would end up with an amp that would measure some pretty tall headroom figures, but it wouldnt be one that I would necessarily want, and would in my estimation, sound pretty whimpy. If a conventional SS amp had a headroom figure much over 2dB, I would look into it's power output specs into lower impedance loads, and if it couldnt deliver substantially more power into, let's say a 4 ohm load, as compared to its output into 8 ohms, then I would not buy it - but that's just me. In the case of the super high end SS designs, what You'll find is close to perfect doubling of power as impedances half, This is the kind of headroom I look for, and make for amps that really have guts, and sound like it as well. They will all clip at some level, what if my 3dB reserve is good for 200msec, but my peak happens to require a 400msec "burst" ?? This is why I still believe the most meaningful and rigorous spec is the good ole RMS measured the way it used to be. That's a 'freaks take, give me SACK as opposed to headroom - all day. When I step on the gas, ("floor it man!") I want all the power I've got for the full 1/4 mile, not just when I come off the line, and then die. Music is very dynamic, but it always bothered me how these designs kind of guess at what the peak requirements should be, and have an upper rail that can "kick - in", but for how long, and how long does it take to recover, etc. I've heard some good things about the Proton DPD and the old Hitachi that I mentioned, and these types were built with extra peak power in addition to an RMS rating, but the peak has no real spec. For non-rail-switching designs, I'd be leary of large headroom specs.
I have been contemplating trying a Yamaha M- series amplifier with auto class 'A' 
I bet they sound sweet! thanks for the insight... :thmbsp:
