Sorry, noob question: you can set the output current (?) that goes through the RCAs? Would that mean that I should set the output „volume“ of my DAC/pre-amp (see below) as low as possible to dial up the HP8 more? Or is that sth different?
Been toying with the ratio of output volume to my amps, so that I can dial them to around 12h, but kinda feel like I get worse results if I go below 30 on the DAC-9 than staying at 10h-ish on the HP8… Can’t be entirely sure yet, though…
The ole' question of how to get the best results out of the HP8. This was my formula. I had 3 different DACs when I owned the HP8. That sounds horrible just thinking about it. Because the HP8 has a lot of gain the 750mw acts more like 2-3 watts. Plus, there isn't a headphone on the planet that needs more than a watt. And I tested this with the builder of my CFA3 which has 16 watts into 60 ohms. The Susvara and HE-6 were tapped at just over a watt. Headphones don't need speaker amps. You can also push current through the right cable and tube combo. Plus the interconnects you use. Personally, I prefer Ohno Cast Copper for all of my cables. I like how much current can pass through, and I like the sound. I find pure silver to be shrill and give me a headache. YMMV...
1. Pontus II with Iris - RCA's into HP8 at 2vrms. This is by memory. Might have been 2.5 VRMs. Don't remember the specs on the Pontus.
2. Exogal Comet+ - RCAs into HP8 and with the Exogal you have no choice but to use the internal pre-amp and digital volume control. Fixed was 100 on the volume, I used it at 92 on the volume for the HP8. I felt that gave me the most flexibility and options. If I used the 12AX7 in driver slot I would back the Exogal down to 88, if using a 12AT7 I would push the volume up to 92. VRMs out of the RCAs on the Exogal were right around 1.8. The Exogal/HP8 was a blissful combo. That DAC was insane. Too bad they are out of business. Like Resonessence. Their Invicta Mirus Pro and Signature were seriously great DACs as they were ESS developers and perfectly implemented that chipset. But they are gone and we are worse for the ware...
3. Cen.Grand Super Clock - 2.5 VRMs out of RCAs. This was my least favorite combo as the Super Clock was a DSD DAC and upsampled everything to DSD 1024 which sounded a bit too syrupy for me and I thought it slowed down the HP8. Only used 12AT7s. I could set the DSD upsample to 512, or a bit lower, but I found no difference or advantage in how it paired with the HP8. The DAC while it sounded wonderful, was not built for tube amps. It is a bit too slow with transients and slew for an amp like the HP8.
I now have the Matrix X2 Pure which is their 10th anniversary flagship and I wish I could hook it up to the HP8 as it is by far the best DAC I've owned and would make the HP8 sing. While the FR spectrum on the HP8 is incredibly linear and full, and the bass is basstastic, the HP8 had one flaw. This is my opinion only! I felt the HP8 lacked in total resolution, which can be mitigated by a strong DAC with great detail and resolute properties.
The beauty of the HP8 besides all the things
@jonathan c has said, and
@Pharmaboy and many others is that the amp has basically no drift. It is super stable and the heatsinks and caps don't move around while the amp biases. This enables the right amount of harmonic distortion and a sound that is just about perfect. Instruments sound life like, and the amp throws a beautiful image and just makes you want to listen to music. Its form factor is near perfect, and it still weighs 17lbs. Oh that copper plate. It is doing so much more than aesthetically adding beauty. It is dampening and providing the amp balance and stability. David Shaw is a genius.
I know of 4 audio designers or engineers who I would consider to be geniuses. I am sure there are many others. But the ones I know are Dr. Jan Meier, Birgir of Mjolnir Audio, Kingwa of Audio-GD and David Shaw. I know Jeffrey Yang of Topping is a smart dude, just don't like his stuff. I know there are many others, like the guys at Trafomatic and Audio Note, and the design team at Naim and DCS.
For the money the HP8 is as good as it gets. As much as I love my Aficionado, and it does sound better than the HP8, it is a totally different amp and I would never besmirch the HP8. It is just that good...
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