QUESTION: picking hi fi headphones that have the best sound improvement while amped?

To hear a bigger "improvement" which is more like a difference using a headphone with a good amp you should look for low sensitivity and high impedance headphones.  The LCD-2 is one example that sounds much better amped.  The Denon AH-D2000 has much better bass response amped.

The LCD-2 aren't exactly high-impedance at 60 ohms. I've heard them driven straight out of an iPod before, and they sounded alright.

 

 

Adding on to what he said, when you have a low sensitivity headphone, most sources do not have the power to drive them properly. The amp provides the necessary power to make those headphones sing.

Purchasing an amp, then the headphones that benefit best with it.  That's seriously backwards!  Why not just focus on which headphones sound the best and fit your music tastes the best, rather than focusing on getting a subtle boost in quality from an amp.

As NA Blur stated, its all about the combination of impedance and sensitivity pairing. I can vouch for it because I myself have D2000 and HE-500 and they both get better from amp. Typically, the one thing that every headphone benefits from when getting amped properly is dynamics. The dynamic range increases when going poorly amped to optimum amping to Schiit Lyr 4 W insane amping. 

 

I guess i really didn't think my questions through.  Who would ever want headphones that have low sensitivity.  Based on your comments, i guess that with an amplified setup, the most improvement i will see is in the lower frequency spectrum?  

 

You're still not thinking it through :) A lot of people have headphones with low sensitivity, think of IEM's. Typically most of them are low sensitivity.

 

As for hearing the most improvement in the lower spectrum when amped, isn't the right way of thinking. For example when listening to music that has bass (20-120 Hz) and cymbal crashes (10,000 Hz, in the thousands easily). So at the same time, to play the bass and cymbal, the headphone driver has to move really slow to really fast. So if you don't have enough power then that transition doesn't happen smoothly or quickly. When you have enough power it can vibrate slowly (bass) and go hit the cymbals and snare (high frequencies, super fast driver movement) and back up or down all very fast. So one might think that the bass is most improved, well that's true to a point - although bass improvement is the easiest to pick up on. There are other things that improve as well like soundstage, imaging, FR, mids, sense of air to replicate the ambience of the track better etc.

 

 

This.

I believe the Elekit Tu-879s is a speaker amplifier, not a headphone amplifier?

 

Just looked up the 6moons review - looks like it is - couldn't you just use the pre-amp out of the Elekit to another amp (but considering OP has to buy another amp...)

The AKG Q701's benefit greatly when amped.

A speaker amp...for headphones?

 

There are only two things I know of for which that makes sense:

 

-electrostatics with transformer boxes that require speaker-level input (much cheaper than buying dedicated 'stat amps)

-AKG K-1000

What? You first say "low sensitivity high impedance" and then suggest high sensitivity low impedance cans to demonstrate some arbitrary point? I don't get it.

I also disagree with the rest of your point about "improved bass response from amplification" (let me guess, this is going towards damping factor, isn't it?) - but that's neither here nor there.

It'll be fine as long as:

A) you can "bridge" the gnd terminal (contact the designer to ask if it doesn't say in the build guide)
B) you rewire the headphones for differential drive (will cause no problems anywhere unless it can't handle the higher Z loading)

Basically building this is what I'd do:
http://sound.westhost.com/project100.htm (that circuit more or less exists inside of most every stereo receiver ever made)

If the amplifier can't handle having the gnd terminals put together, you can re-wire the headphones to run balanced (so each driver is to each channel, +/-), and throw some resistors into the line to protect the headphones and drop the level.

If you don't want to build that box, HiFiMan sells one pre-made for around $50.

Yeah, an amp is an amp. The notion of the "dedicated headphone amplifier" is a machination of marketing run amuck. Small adapter boxes can be added to speaker amps that lack them internally, or you can just tap right to the outputs assuming you don't get too insane with the volume control and the amp is okay with the loading. I'd go with the adapter to protect the cans, and not have to fuss with re-wriging. But you could always just drop some resistors in-line and run differential and life is good. The K1000 is insensitive enough to handle a higher input, but same idea in principal across the board - the device doesn't have to say "headphone amplifier" on it to work very well (and in most cases, devices that DO say that, work very poorly despite costing a fortune).

There's also basically every receiver, IA, etc ever made with a headphone jack that fits into this criteria. FWIW.

 

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.

 

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.

 

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.

Edited by NamelessPFG - 8/6/12 at 8:32pm