The Hafler DH-200 has been a good, clean, consistent amp for me and used for everything from near-field monitors to runing the high-end on two and three-way speaker systems. I've added a review from Edward Dell and David Vorhis below that really says it all. Be sure to check out their entire article at this link - REVIEW: HAFLER DH-200. I've also found lots of online recommendations and news about the amp, so its well supported and respected in the pro-audio community. You can check out the Manual here, and you can click on the photos to enlarge them...
-Bob-
On the test bench the DH-200's performance is among the most impressive I have seen. It handles with ease just about everything you throw at it. Since most of my measurements tend to show very low distortion and appear to reveal no particular pattern, I'll summarize most of them focusing on those I feel to be significant in one way or another.
Hum and noise are quite low for both channels, measuring 82.5dB (R) and 85dB (L) below 1 watt with the input open. With a more realistic source termination these figures will improve a few dB. For a 100W output add 20dB to the S/N. As these are wideband measurements, what one actually hears will sound even better with most present-day signal sources. I measured both channels' gain as 26dB, which translates into a nominal 1.4V rms input sensitivity (for a 100W into 8 ohm output).
In short, the DH-200's distortion levels for both THD and SMPTE IM are extremely low. THID, for example, is basically near the residual level of a Sound Technology oscillator/analyzer at all but the highest frequencies and power outputs. At 20kHz at 100W of output it gets as high as 0.013%, and at a 50kHz 100W level it measured 0.04%! For levels from 1 to 100W below 20kHz it remained as a rule well below 0.01%.
That this amp can deliver such clean high level power at frequencies as high as 50kHz is, I am sure, due in large part to the MOSFET output stage. Many bipolar output amps will either self-destruct or melt fuses when asked to deliver 100W above 20kHz; I do not recommend such testing to the inexperienced. The DH-200 appears to shrug off such stresses and happily deliver clean watts.