How about stereo system preamps?
Feb 26, 2008 at 5:53 PM Post #16 of 24
I have a Headroom Micro and HeadAmp AE-2 and recently bought a Cayin HA-1A.

I like all three but I also use the headphone output on my NAD C162 preamp. I have used it with SENN650s, Audio Technica ATH-900s, and DT-880s plus some other things like SENN 280s. I think it sounds very good. I believe the NAD generally gets decent reviews for its headphone output.
Feb 26, 2008 at 8:20 PM Post #17 of 24

Originally Posted by Michael10 /img/forum/go_quote.gif
I believe the NAD generally gets decent reviews for its headphone output.

I have heard and read this repeatedly but my only experience with a NAD headphone jack is on my 3240PE and I can quite honestly state that it's the worst headphone socket of any component I own.

Listening to the headphone out on my Toshiba M15B Power Amp and especially my TEAC A-H500 is a far more rewarding experience.

I see people commenting that the Melos SHA1 (an example of which I'm in the process of buying from a head-fi'er) is a good preamp that happens to have a good headphone stage.
I was under the impression that the SHA1 was built from the ground up as a headphone amplifier.

Am I mistaken?
Feb 26, 2008 at 9:00 PM Post #18 of 24
To the OP, this topic comes up every month or two.

A preamp is designed to provide a volume control and boost the output to a power amp. Sometimes the boost is enough to power headphones, sometimes it isn't. And it depends on the headphone, as well. Grados and Audio Technicas, generally, are easy to drive. Sennheisers and AKGs are not; you usually need a dedicated amp for them to sound their best.

So, you really can't make a generalization about headphones and preamps. The good news is that a number of sets are designed to do both. There are a number of DIY designs that do both, as well.
May 11, 2008 at 3:00 AM Post #20 of 24
I have a Audio Research REF 1 with similar specifications. I e-mailed Headroom about running a set of balanced HD-650's out of the pre-amp outs and was told that it wouldn't work or at least was not advised. The output specs for the LS17 call for it to go to a power amp with a minimum of 20,000 ohm impedance. Most headphones are less than 600 ohms. You might be able to use the tape out but I don't know.

Or I think you could run the tape out to a tape deck with a headphone jack.
May 11, 2008 at 8:59 AM Post #21 of 24
Please, somebody answer tfarney, and his direct question about the headphone section coming directly off the amp (NOT just the preamp) via a nest of resistors.

My experience is that that can sound exquisite, when that is the implementation method, as with the current Denon integrateds.

As Unc sez, pure pre-amp implementations can be hit-or-miss or sorely lacking, as in the hole on my current Onkyo cd player, which is weak-kneed and only good for monitoring-the-signal purposes (unless you're an uncouth lout).

I remember thinking, as a poor college student in the late 1970's, that I could run a pair of Koss/Radio Shack Realistic cans out of the jack on my solo component, a Pioneer cassette deck.

Yikes. Flat as a pancake. Just like my current Onkyo cdp jack.

Yet this last winter, I found the Denon integrated amp that I bought for like $1100 from Crutchfield to have about the best headphone-out performance of any dedicated headphone amp that I've ever had or ever heard. I was told by Denon that they resistored down off the main amp.

Dennis Had, I believe it was, also told me that that was the way that Cary does things, which, he said, "is the preferred method," and produces the great headphone sound quality that their products exhibit.

So, yes, it's hit-or-miss, but I think that this forum has a profound amount of confusion and ignorance on this topic, and an unfair bias toward dedicated amps, many of which are remarkably nothing special (except for their expense or style).
May 11, 2008 at 12:09 PM Post #22 of 24
The Conventional Wisdom assumes that the op-amp based headphone sections of preamps, integrated amps, receivers and cd players are weak while it promotes many commercial and DIY headphone amps that are...ahem...op-amp the greatest thing since toilet paper on a roll.

Does the fact that they both have op amps in them make them equal? Of course not. Does the fact that one is a dedicated headphone amp and the other is built into another device make the former superior? Not again.

Plug your phones in and listen. If it sounds good it is good.

Gregg F - I've gotten some feedback on the subject of headphone sections implemented from the main amps through resistors in other threads since this one was new. Some have warned that the resistors can cause all kinds of problems - noise, loss of SQ, etc. Of course the preferred audiophile method of volume control is a stepped pot - a nest of resistors - so I take that warning with a grain of salt. I've also tested the method by resurrecting my 70s Harman Kardon integrated to use as my primary headphone system in the home office. It sounds great. Powerful, warm and detailed. As good as a dedicated head amp? Not the very best of them, I'm sure, but it's 30-year-old specs are up to, if not beyond all but the most expensive tube amps. And as a dedicated headphone amp it has more headroom than Danny Devito in an atrium lobby, so it's approaching nothing close to challenging its abilities.

Last but not least, I finally got feedback from Panasonic on the implementation of the headphone section of my digital receiver (SA XR-55). I had suspected, because it was so incredibly quiet, fast and detailed that it must somehow be using the main Equibit digital amps. It is not. It is using an op amp. And now that I know that, it is still incredibly quiet, fast, powerful and detailed. Go figure. Maybe it's because the path is all digital until just before it hits the op amps (with, I assume, an inexpensive dac chip in front of them). I don't know. I just know what I hear.

May 11, 2008 at 2:15 PM Post #23 of 24
My Nikko integrated has a stellar hp jack. I have owned (and heard) a LOT of dedicated headphone amps in the last year and only my current Doge has sounded better than the Nikko. The Nikko is powerful and detailed and warm tto, and drives absolutely everything I have thrown at it with ease. Nikko amps (and pres w/ hp, the "Beta" models I think) come up on the bay of fleas all the time and are, imo, worth trying. My amp also does a great job driving my Cantons and has tone controls that work subtly and well.

More headroom than Danny Devito in an atrium???/ Love that!
May 11, 2008 at 5:53 PM Post #24 of 24
I don't understand the concept of balanced headphones very well but if you have balanced outputs (as I do) on your pre-amp, is there someway to use the outputs from the preamp to go straight to a set of phones. Or could you use the tape out. The Audio Reserch has about 8 or 10 inputs and outputs but no headphone jack.

Sorry for my electronic ignorance.

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