palmfish
Headphoneus Supremus
After much searching, the one and only picture of the inside of the HDVD800 that I could find...
Originally Posted by wisemanja /img/forum/go_quote.gif
[snip...]
By the way, I still have not determined whether or not the HDVD800 is fully balanced all the way through the DAC section as well. I.e., in addition to the 4 internal amps (2 for each balanced channel) there would be 4 DACs as well. I.e., 2 DACS for the left channel and 2 for the right. One DAC would handle the normal signal and one would handle the inverted signal for a given channel. These would each feed independently to the inverted and non-inverted amps for the output to the headphones.
...the slew rate doubles. Given that a single amp can change it's signal output at a given rate, connecting the second inverted amp results in the inverted signal moving away from the non inverted signal at twice the speed as a single amp's output by itself. The results are a much quicker amp which can improve openess.
The Burr Browm PCM1792 (which is has been reported to be in this product) is a stereo DAC, so only 2 parts would be needed.
Here's a good discussion on balanced headphone amplifiers...
http://www.amb.org/forum/benchmark-engineer-on-balanced-v-unbalanced-headphone-amps-t326.html
Anyways, I'm not knowledgeable enough to assess the photo I posted above, but maybe someone here knows enough about amplifier PCB's to look at the opamps and caps and tell us if it is fully balanced?
I had a Violectric V200 & V800 before and there's a number of tweaks related to them (ground lift, DC coupled volume control, gain settings etc) that make differences so small that they fall within the realm that it could be the users imagination creating the difference. I was worried that going balanced with the HDVD 800 would produce similarly small gains, but as it turns out the difference was big enough that there's no doubt it sounds better.
Either they made the single ended output very bad, or balance in general gives more control form the amp to the headphone because the "Push and Pull" on both porlialtry