This is incredible piece of electronics. I am using it with DarkVoice tube amp and the results are just phenomenal. My alternate DAC-AMP was Audio GD NFB11. This new combination is significantly superior. With back to back A/B testing I can hear much more natural tones with D50-DV compared to NFB. Overall soundstage is better, sound is way more clearer with more slam. The tube amp also has some play in this, but I also tested DV with NFB DAC, and there is clear improvement in the resolution with D50. There is better S/N with D50 and background is significantly darker. Its like switching from LCD screen to OLED screen. At the price I would say its a must buy.
The headphones I used for testing: HD6XX, Hifiman HE560, Audeze EL-8 Open, Monoprice M1050 Open.
I am also playing with DSP settings on D50 and there are some very interesting and subtle differences, will add more on this later :).
AmJoshI have a DarkVoice on the way, should be here tomorrow. I had the option of buying a used THX 789 for $250, but went with the DV due to the reviews I've read on how well it pairs with the Senn Hd650's/6xx. Did I make a poor choice? I will be using a Topping D50 as my DAC.
carboncarouselMan, you put any amp against 789, it's gonna lose. If you have a choice of getting only one amp, there is really no competition to 789. Don't get me wrong, DV is a fine amp. I have it too, but it has lot of limitations. It will not pair well with any other headphones, especially ones with less impedance as well as planar headphones. You can forget about IEMs. I'd recommend to change your purchase if possible.
AmJoshI wish I would've changed my purchase, like you said. I received the DV, with a broken power switch included. The DV still turned on, but I had to unplug/plug for power. Well, on the second night, I moved the amp - just to reposition it a bit, and I guess the innards of the power switch were loose, and must've made contact with metal inside the case. Blue spark at power switch area, loss of power, blown fuse, now it won't turn back on.