I am not picking on the Dave here, because this happens with every amp, all have limitations. Run out probably wasn't the best term to use, limited probably is better (as Rob used). When I said it will run out, I was speaking in general terms, not for the 4z or the 4 or anything else as I have no idea when this will happen for specific gear, but at some impedance level it will happen since we don't have an endless supply of voltage and current. I was trying to make the point that amplifier power performance varies with impedance and why this is so, as I am sure you know but just so as to answer the original question. To clear things up a bit, Dave's limits are 0.5A max current at some impedance level and 6.8V max volts at some impedance level. If the gear works happily within these limits, then no problems in terms power, especially as the Dave has almost zero output impedance. At say 200 ohms, Dave is limited to 231mW, at that point the voltage will probably start to clip as we cannot supply anymore, and the distortion will go up very very quickly. Note, that if you needed 112dB SPL, it will run out and never get there or it will with lots of distortion. A different amp might be able to produce 1231mW at 200 ohms, it has a different limit but still limited. At 15 ohms it does 3W, so power varies greatly with impedance for amps. Regardless what impedance you choose it will always be limited, not enough volts or current can be supplied at some point (not relating it to any specific gear). I think I and some others were arguing in terms of how the gear was affected and you were arguing in terms of purely SPL requirements, that is where the confusion arose I think. Reading the original question again now, I believe it was in fact about SPL as you answered it. BTW, nice to have Rob around to answer all the questions.
Dave is a very interesting case though, it is probably the best DAC and amp out there, seems to have enough power, but just doesn't rise to the level of even of some way less qualified gear with the LCD4 (for me anyway). With my LCD3, the Dave was one of the best I have heard, it was just a little bit too dark but otherwise great. It didn't have any of the issues like I hear with the LCD4. What I hear with LCD4 does sound to me like its a power issue yet the CMA800R I use now has about the exact same amount of power yet sounds fantastic. So I can't explain it, maybe just that synergy thing again. I do hear a lot of others complain about the same thing and it is fixable by adding an external amp, yes it adds a flavor but things come alive. The TT2 may give some further clues. I got to listen to the TT2 but no LCD4 around just a HD820. Sadly it was easily out classed by the Dave for me so I am looking forward to the Dave replacement one day. I will try to test the TT2 with the 4 at some point though because who knows in this audio game, I hear if you put a brick on top it sounds better.
