[obobskivich]

I have to admit, the world of amplifiers is complicated and a lot to wrap my head around, but my general distinction is that a "speaker amp" is built with output to speaker wire terminals in mind, while a "headphone amp" is generally going to use a TRS jack for output to most headphones, barring the fringe cases like XLR or Stax plugs.

So, this is a bit misleading methinks. Basically all an amplifier (of any type) is doing is providing gain to a signal - it "injects" power by making the signal bigger. There is specialization relative to the thing it's supposed to plug into, of course (e.g. the Koss E/90 sitting next to me is designed to throw a few thousand volts out, but can swing less than 5 mA of current across both channels - the speaker amplifier driving my speakers puts out maybe 20-25V, but does it at a few amps). The termination doesn't really matter beyond can things connect - bare wire is always suitable, it's just kind of a pain in the neck to use it repeatedly. One thing headphone amplifiers are designed to do is run -ve common ("single ended") which some "speaker amps" will have a big issue with (they'll blow up), for example you cannot do that on any Tripath chip (it will let the smoke out), but they can run -ve separate ("differential") all day long, into any load that is within their operational range (which is like 6R or 8R and up).

As for the actual circuitry behind the outputs, there's all sorts of crazy designs out there, and nobody seems to agree on what's better or what's worse. All I know is that a lot of amplifiers get stupid expensive for what seem like marginal increases in sound quality, and the only reason I'd even consider buying a dedicated headphone amp is simply that electrostatics don't work without specialized amplifiers.

I agree that people tend not to agree, because there's more than one way to skin a cat. The gain and amplification stages in my current speaker amp are identical in function but very dissimilar in implementation to that of the unit they replaced - I'm not worried about what it looks like inside though, as long as the output works. A lot of dedicated headphone amps are just hilarious though; you take a $2 opamp and a $0.10 pot and call it a "hi-fi product" and it becomes $500. A lot of them lack any form of output protection ("because it degrades the sound") and often have worse channel balance than the dollar rheostats or ganged pots you can get at RatShack for projects. That's just a kick in the teeth imho.

As far as specialized amps go - yes and no. The rise of the dedicated energizer is a more recent thing, and it's only for headphones - it's more efficient certainly, but transformer coupling is still how speakers work, and is still rational for electrostatics (but less power friendly).

For that matter, you're an ESP/950 owner, so I'm sure you know about all the slag the E/90 gets among 'stat enthusiasts and all the recommendations to re-wire it with a Stax plug so you can use Pro bias Stax amps...yet some say that the E/90 actually isn't that bad of an amp.

Yeah, the E/90 isn't popular because it doesn't cost enough, doesn't have a die-cast body, doesn't have tubes in it, and isn't bedazzled. This is basically the same reason "we" don't see more receivers or other hi-fi devices being used to drive headphones. They aren't special enough.

 

[captouch]

Hifimans (HE-6 and HE-5/5LE/500 as previous poster indicated) all benefit greatly from proper amplification. I'm running both 5LE's and 500's off speaker taps now.