I've had my HDV 820 for a few months now, and the HD800S for a few months prior to that. I have been wondering how I should summarize this combo...so i'll just say this: I kind of get it. Sometimes I think of this amp like Schrödinger's cat, it both is and isn't alive in a time and space where it's never been easier (and simultaneously more complicated) to piece together a good headphone solution. It's also almost five years old, and still has a retail of $2399 (I did not pay this, my unit was $1399+tax). In 2021/2022 that can get you a
whole kaboodle of system.
Before HDV 820, I ran the Valhalla 2 with very nice Brimar CV-4033 input tubes, which was incredible on the HD6XX, but I never really felt that same magic with the HD800S. I bought the HDV 820 for a few specific reasons: wanting solid state instead of tubes, something that was fully balanced, something that would not "filter" any inputs (which is what I hear the Sony TA-ZH1ES does), but most importantly
I wanted to take the guesswork out of a great solid state amp option for running Sennheiser headphones exclusively. In that regard, I feel like I hit the jackpot with this thing. However the on-board DAC was an added bonus for me and not really something I seriously considered because I wanted to continue using my Bifrost 2. I seriously considered the RME-ADI 2 FS instead of the HDV 820 but it felt like the opposite of what I wanted at the time- it seemed more DAC first and amp second.
Listening to the HDV 820 for the first time, I will never forget how floored I was with everything I was hearing. The richness, the lower-end extension I was getting was unheard of for me on this headphone; miles ahead of what the Valhalla 2 could do IMO. With that, I relegated the 6XX to the Valhalla 2/Bifrost 2 stack, and used the HD800S exclusively with HDV 820.
Enter - curiosity killed the cat. Now that I love the HDV 820 amp, I started wondering about how to maximize my rig, which ended up being an exercise in Gear Acquisition Syndrome. Will the 6XX sound great out the HDV 820 using a balanced cable? What if we upgraded the USB cable? Upgrading Bifrost 2 to Gungnir Multibit? How about trying out a few pairs of XLR cables to run the Bifrost 2 into the HDV 820? Turns out I did really like the 6XX via XLR into the HDV 820, enough to sell Valhalla 2 and a couple other pieces of not-used-anymore gear to fund more cable buying. All the new cables I got did end up keeping make a noticeable difference to me, but...looking back I can't help but ask myself - have I completely missed the point of the HDV 820? Isn't the whole point of this unit is to be a cohesive experience, from start to finish, with the HDV 820 and 800S combo achieving what Sennheiser found to be the "perfect synergy"? Have I ruined that? Maybe, but if ruining that is wrong, I don't wanna be right.
All in all, I find that the music I listen to has never, ever sounded better with this setup. I know better from other hobbies about the whole "endgame is a myth" thing, but with the exception of a US version of the Luxman P-750u MKII (which as far as I know isn't going to happen), I can't say I'm very interested in anything else headphone amp wise at the moment. At this point I plan on looking for more music not available on streaming services instead and filling out more of my CD collection, maybe start taking trips to concerts or something.
A few things I wanted to mention specifically about the HDV 820 itself:
- Overall I prefer using my Bifrost to the onboard DAC of the HDV 820, but it's really just that, a preference, especially over USB. Even after spending tons on cables and soon-to-be upgrading the Bifrost, I am sure it will almost certainly be still preference rather than it actually being better. I also wouldn't shrug if anyone wanted to use the USB only for the HDV 820. Might recommend a USB cable that splits the signal and 5V lines for more isolation since as far as I know there is no galvanic isolation on the USB of HDV 820.
- I only briefly explored the DSD capabilities of the HDV 820, so little so I left it out of my impressions. Nice to have, though I am OK with PCM-only DACs and playing CDs. Might be a good tool to have if I ever get curious about DSD again. The few tracks I tried didn't seem all that great, but limited time spent so I may have done it wrong.
- I dislike the coax input quite a bit. Really made music listening un-enjoyable. Switching back to the Bifrost was a big improvement. Haven't bothered with optical on either DAC.
- That 6.3mm/3-pin XLR jack on the front...I think I dislike this more than the coax input. I look at it now as a courtesy input but really, the XLR and pentaconn sockets should only be used. SE out performance has got to be better on nearly every other amp I've ever used.
