Integrated amps are what you'd want if you're looking for a volume knob. Volume is most of what the preamp is, so in general a power amp is a fixed-gain amp; you feed it x-voltage in, and it applies x-gain to the input. The whole point of the pre is volume attenuation and/or voltage gain. Integrated amps have both. Some call these "receivers" which is a word that's been kind of retired since the A/V receiver took over that market. There's plenty of current production integrated amps out there that are quite a bit nicer than AVRs.
I know a few people using these as well: These also look just like another amp - I can't think of it's name at the moment. I think grokit uses it.
There's also that. That's the Behringer version, Grokit's using the Alesis. The thing I don't like about the Behringer is it has no relay mute on startup (it does have one on shutdown, and the mfr assured it it starts up in a sequence that mitigates thumps. But for headphones I still don't like that. I nearly got the Alesis, but Skylab assured me that what I already had (Marantz PM6004) was probably better, so I upgraded in style to an MM7025 power amp instead. My Woo WDS-1 has volume control on it, so I didn't need the crummy preamp from the 6004 anymore. Even Marantz admitted the PM8004 has a better preamp than the 6004, so that should give an idea of the quality of that preamp in audiophile terms My bigger problem with the 6004 is just that it's crazy high gain (noise) for no reason.
However from my conversations with Grokit about the Alesis, he's extremely pleased with it and easily recommends it, so at least for HE-6 it's definitely a cheap option, and maybe for the HE-500 too. Not as cute and space saving as that Emo though.
It should be mentioned that the "volume knobs" on those rackmount amps aren't really meant as volume control, they're input trim controls. They're supposed to be one time set and forget to match the output levels of the pre/source. However technically they can be used as volume. The idea is, in pro audio terms, a set of monitors coming out of a pre or line level source would need much less gain than, say, a mic, but it's presumed in both cases level control is on the mixing board. However in practical terms they can function as an attenuator since it does attenuate the input voltage before the gain stage.
Received my new cable today. Hooked her up. Absolutely love it. It's so much lighter than the stock hifiman cables and way more flexible (braid within a sheath). The adapters are just incredibly smart. I can swap to 3.5mm (with 1/4th adapter) for my normal headphone amp(s) and jump straight to speaker taps just by clicking the XLR connections and never have to unscrew the cable from the hifiman (which is one of my least favorite things to do, it's a pain to screw those on / off, I always feel like I'm going to eventually damage them doing it too often). So this is just a great simple and universal way to play around with all sources.
To test it out, I hooked up to my Pioneer and Onkyo receivers just to see if it would blow up or not and make sure everything worked, because the Emotiva Mini isn't here yet, it shipped today, so should be here soon. The Onkyo & Pioneer are rated in the 80wpc and 110wpc ranges respectively. Without getting into too much detail just yet, I have to say, I'm quite impressed with how good the Hifiman is with a simple receiver setup. Kind of makes the "all in one" really stick out as a really cost effective way to power these things. I noticed I didn't have an issue with volume, I had to turn it up to the higher level of listening volumes compared to speakers for the headphones, so definitely not worried about blowing up my headphones so far. I actually like this setup, I have the DAC and equalization and other fun options that AVR's can do with speakers all setup into a great headphone. As for the sound, it's much better than the headphone output of the same AVR. On the speaker taps, there is not a noise floor unless I put the volume up in the high-moderate level range and even then, it's the track, because when I hit pause, it's nearly inaudible. These are entry & mid-level AVR's, not even something "excellent." My Pioneer VSX1121 is a very nice match so far (110wpc). So if anyone wants a really neat way to power a Hifiman, a simple AVR with speaker taps is actually a pretty cool way to go. Sound is excellent. It's not "better" than a good headphone amp setup so far, but it's simple, and a lot more "universal."
I'll update with pictures of everything once the Emotiva amp shows up so I can compare a speaker amp and DAC (NFB12 as DAC) setup, compared to AVR's, and the HE-500's on speaker tap.
So far though, this is absolutely entertaining. The HE-500 definitely can take the energy from speaker oriented amps. It's not scared of them at all. Time to start testing more powerful equipment (as I'm sure the AVR's were outputting way less than their rated wpc).
I'm looking forward to hearing your emo impressions. It's interestiing that those AVRs are turning out so well, but ultimately, AVRs are...well...nasty. Especially entry & mid-level ones...there's more compromises than should be at that range, and I've never heard an Onkyo AVR that I'd consider "good sounding" with any speaker. Especially not the entry & mid tier ones. They're dependable, but ultimately any upgrades I've made are better. So, yeah, I bet you're in for another bump once your new amp comes in! (FWIW, compared to an Onkyo 504 and a 604, I've found a Denon 2310 to sound far better with my JBL Studio L wallmounts to the point that both Onkyos lacked any and all detail by contrast and had a bloated midbass. It also has a real HP out (main amp + resistors) rather than the cheesy op-amp HP amps that the low models have.) It still doesn't hold a candle to the 7025, but in some ways it can give the 6004 a run for its money.
Both really. The NFB12 is not the most lively of amps. It's got a nice DAC in it. But it's amp portion is not the greatest from Audio GD. The Lyr was warmer and meatier. The VSX1121 sounds warmer, sound stage is different, I like it a better, it's not significant, it's subtle. I definitely however like the function of an EQ added that isn't coming from foobar and doesn't require a pre-amp or wired in hardware EQ. The AVR is of course huge unfortunately compared to the NFB12 of course, so it's size is rather cumbersome. I will say though that so far, listening on the VSX1121 compared to the NFB12, the HE-500 does sound more like what I would expect from a good stereo speaker setup with the AVR on speaker tap than it did from the NFB12. But I need a few more days to really get into it and form a better opinion, this is all just preliminary and of course I need to let the idea of the honeymoon "love" wear off from simply liking a new toy that is more fun to use wear out so I can be more objective.
By the time you're done this project, you know you're going to end up with an HE-6, don't you? It's the only HE you're missing in the collection and you'll have all those huge amps just sitting there looking lonely...