Originally Posted by ProtegeManiac
If he works in a very quiet studio where even the A/C isn't audible, then he can use those amps at such a low volume level he probably isn't anywhere near 0.05% THD, and won't need as much current out of them either. Also, again, the problem with a lot of similarly priced consumer/"audiophile" products is that they aren't actually "hi-fi" - between two amps under $200, the power supply would be comparable, and so the pro amp that has less coloration compared to a consumer product that adds unnecessary warmth is always preferable unless size is a problem. When you factor in for example a transparent consumer amp at $400 with a really clean and powerful output however that's when you can notice there's a difference in some headphones. I've tried the K701 off a Samson four-way headphone distributor before at a pro audio store here and felt like they didn't have any "oomph." There's neutral, then there's thin and makes me sleepy - not to compare apples to oranges but the Samson studio monitors there actually sounded like real music (I eventually ended up with a Grado a year later). Years and years later I tried it with a Burson Soloist and I would've bought both if I had enough money (also tried the K701 with my own Meier Cantate.2 and it was still a lot better than the console). Still, if the choice was between oversized pro amps and cheap consumer amps, as long as size isn't the problem then definitely go with the pro amps. With more expensive amps, well, the pro amps with huge power supplies and running in Class A tend to be waaaaay more expensive than consumer amps, like Sugden and SPL, so I'm not one to buy them new (heck, who am I kidding - I haven't bought any audio gear new since my speaker days).
A little OT - their installation on the S-Class is only great for people who don't really want to fuss around with their car's audio system, and want to share the sound with the front and rear passengers. If you don't give a rat's arse about what the passengers would hear, especially if the occasional passengers you have in the car at the very least have no idea what imaging is anyway (if not tone-deaf), a fully active system applying time alignment processing with custom delays on each tweeter, midrange, and midwoofer relative to the subwoofers and each other will still do better recreating a proper image on the dashboard (provided you know what you're doing). That one also uses similar processing but they went as far as putting a tweeter (likely a fullrange driver) in the front, simulating a surround system, to help center the image, the same way that in some rooms a center channel speaker is better than a 2.0 or a 4.0 with a phantom center.
Funny, I just found out that Grapevine Headamp 4 is actually made by SPL, didn't realize it at first. But yea, that's what I'm worried about with these amp, that they might be too thin or analytical. I mean, they're designed for studio monitoring, not listening to music, so they might be tuned to give a more clear insight into the mix, rather than musicality or some pleasant coloration. But then again, I've never really noticed much difference between headamps. I mean, so far I've owned the Project Headbox SEII (150€), Little Dot MkIII and MkV (both around 200€), Nuforce HDP (500€), NAD D1050 (500€), Musical Fidelity V-CAN II (100€) and Musical Fidelity M1HPAP (700€), and on top of that I've tried multiple integrated amplifieirs and receivers headphone outputs (probably like 30 of them, I went crazy last summer and took my headphones into every hifi shop in my city) and soundcards, best of which for headphones were the Asus Essence ST (200€) and Onkyo A5VL (400€). As you can see, prices vary from cheap to quite expensive, but to be honest, they all tend to sound like 95% the same, the only real noticeable difference being the Little Dot MKIII since it's a tube amp. All the SS amps sound 95% the same to me, even with Beyerdynamic T1's or K701's which are my most revealing headphones, and even using low impedance headphones out of 120 ohm output impedance integrated amplifier only minimally changes the sound signature. The only really noticeable differences between amps that increase the listening pleasure are the noise levels and channel balance, which is worse in cheap amps, almost always in my experience. Other than that, I'd be hard pressed to differentiate the V-CANII from the M1HPAP in a blind test at a normal listening level, even though one costs 7 times more. Ok, maybe it has a bit more weight in the bottom end and a bit bigger sense of space, but that comes from coloration, not neutrality or transparency, definitely not worth 7 times the price. Hell, plugging the T1's into an iPhone and comparing the sound to the M1HPAP is quite interesting. I know a lot of people would find it ridiculous, but at the same volume level, playing the same track trough the M1 fed by the iPhone, or plugging the headphones directly into the iPhone, sounds pretty much identical. Differences might be there, but they're so slight they're virtually not noticeable and definitely don't change the listening experience.
That's why I'm kind of thinking that getting a Class A pro amp with several outputs, each capable of driving several headphones in a decent manner acting pretty much like a wire with gain, would be quite nice and decent value for money. I'll see if I can arrange a listening session with some of these amps in one of the stores, I would assume they'd be willing to do that.