On the issue of amplifying the HD800

Much has been made about the inductance of the HD800, and the need for certain types of amps. Some people swear they sound great on tube amps, and some insist that due to the inductance, any amp with a high-ish output impedance will not sound as good as they should, and that this includes many OTL tube amps. It's a complex issue, and that doesn't mean the HD800’s *won't* sound good on any given OTL amp. But on the SinglePower Extreme, the treble emphasis was slightly worse that it is on the SS Audio C2C, which I would not have expected. I have never considered the Extreme to be at all rolled off, and of course I cannot measure its output impedance, although SP claims it to be 20 ohms, which isn’t very high, so it's likely IMO that the amp isn't contributing to the treble emphasis I hear, and that the slightly laid-back C-2-C might be masking the HD800’s treble list slightly.

I also tried the HD800 with the Darkvoice 337 ( Tung-Sol mesh-plate 6SJ7GT + GEC 6AS7G) and the 336SE (Shuguang Treasure CV181 + Sylvania 6AS7G). In both cases the treble emphasis was just a tiny bit more obvious, and just slightly more pronounced, than with the SS Audio-GD C2C. I tried the Graham Slee SRG+PSU1, and the treble was between the Extreme and the C-2-C, but on all of these amps, the feeling of a bit too much treble energy never went away. On the other hand, I felt the treble performance on the Decware CSP-2 was basically identical to the C-2-C. So in the end, I think too much was made of this issue of amp type (as is almost always the case).

The HD800 do not, IMO, change their own character radically from amp to amp. Being as revealing as they are, the HD800 certainly will let you know the difference in the sound of different amps, or different tubes. And of course it is difficult to generalize about tube amps, since you can often get the exact sound you're looking for by tube rolling. For example, if I took the 5998's out of the Extreme, and put in RCA grey-plate 6AS7G's, the sound would be very different, and I probably wouldn't notice any treble elevation in the HD800, since the RCA is a soft-sounding tube.

So the point is that with OTL designs there is a potential issue that should be noted - nothing more than that. And since one can alter the sound by using different tubes, tube amps still offer nice flexibility in this regard, and a great tube amp can still sound great with the HD800. My favorite combo ended up being the Decware CSP-2 and the HD800. The Decware, with Amperex 6DJ8’s and a Sophia Princess mesh-plate 274b, when combined with the HD800, provided enough lushness that the sound was just beguiling, and I didn’t worry much about the tipped-up response – the music was enthralling.


Build Quality and Fit

I found the HD800’s very comfortable to wear for long periods of time. They are big, and they were right at the limit of earcup size for my head, but they were within the limit. I of course heard the “pinging” of the spring that people have commented on, but I wasn’t bothered by this. The cable isn’t at all microphonic, which sure is nice.