[davebot]

I know this is blasphemy of a sort, but I'm asking myself if I really need a headphone amp.

My NAD receiver has a headphone jack, and it seems to drive my DT 880 just fine. I'm guessing that the headphone jack is a feed off the power amp section of the NAD, which is 75 wpc + 6 dB dynamic headroom, and a good sounding amp with my Vandersteen speakers.

To play devil's advocate, I argue that the NAD's got to have way enough power to drive these phones. And the NAD is a good-sounding power amp. So why should I expect a dedicated headphone amp to make much of a difference?

Now, don't take me too seriously!

I'm just looking for a reality check before I join you all in the land of the emptied wallet. I know that I can be influenced by my expectations, and I'm looking for some solid technical reasons to suspect that I can improve on the NAD.

Thanks for playing! If I tread the fine line of heresy, I trust that you will forgive me and lead me gently back to the path of righteousness.

 

[ampgalore]

If the headphone jack sounds good enough to your ears, then save the money, don't buy a dedicated headphone amp.

Else, your wallet will be a lot slimmer before you know.

 

[SunByrne]

Totally legit question.

My understanding is as follows (which may be corrected by someone more knowledgeble):

Certainly, the NAD has enough power, and if you actually dumped all 75 wpc to your phones at the same time, you'd fry your headphones badly. Speaker amps are designed to drive loads with very small impedance (similar to resistance, but frequency-dependent), and the trick with good amps is their ability to drive loads with VERY small impedance. As in, don't plug a cheap amp into 2-ohm speakers or somebody's going to fry (though your NAD can probably handle them).

Headphones, on the other hand, often have very HIGH impedance. So the electronics in your speaker amp are poorly-optimized to handle this kind of load. It's my understanding that the headphone out in most receivers is just a resistor thrown into the output path for the speakers, which means the careful engineering to accurately drive speakers is not going to help your receiver do a good job of driving headphones.

That said, I also have a NAD receiver at home, and it's fairly decent for relatively low-impedance cans, but I suspect a dedicated headphone amp will do a better job driving your 250-ohm Beyers. I recently upgraded to a fairly modest headphone amp and it definitely sounds better than did the headphone jack on the NAD, even for 64-ohm cans. (Bass in particular seems less flabby.) This is almost certainly because the circuitry is designed to drive higher-impedance load, namely headphones. The difference is not enormous, but I expect it will be larger when I upgrade to harder-to-drive cans (HD595 coming soon, maybe).

 

[rsaavedra]

Thou have treaded the line of heresy, and hence you must be cast into the shadow from whence you came

J/K

Actually, I own a Marantz SR-4000 A/V receiver for a few years now. Few months ago I got Sennheisers HD650 + the Zu mobius cable, and have tried it with my receiver, with a Perreaux, and recently with a Grace 901 courtesy of agile_one. These other amps have allowed me to do comparisons, and made me realize how well the Marantz headphone out can drive the 650's. The Marantz is a tiny bit hazy in comparison (I guess doesn't have as good S/N ratio, or as low a background noise spec), but it's really a tiny bit, and maybe sounds a bit warmer compared to these dedicated amps, but it is punchy and drives the Senn's with ease, musicality, authority and power.

(Sources I've tried these combos with: stock and Sacdmods Sony NS500V, stock and modded Toshiba 3950, Pioneer 563AS, and Cambridge Audio Azur 640C. Interconnects: Monster Interlink 400MKII's, and Silver Sonic DH Lab BL1's)

 

[MuFu]

Quote:

Originally Posted by davebot I know this is blasphemy of a sort, but I'm asking myself if I really need a headphone amp. My NAD receiver has a headphone jack, and it seems to drive my DT 880 just fine. I'm guessing that the headphone jack is a feed off the power amp section of the NAD, which is 75 wpc + 6 dB dynamic headroom, and a good sounding amp with my Vandersteen speakers. To play devil's advocate, I argue that the NAD's got to have way enough power to drive these phones.

I've just switched from a NAD C350 headphone out to a Headsave Go-Vibe (source is an M-Audio Revo). The difference is marked. Most obviously, the latent noise floor is much lower - barely any hiss; even at high gain. I've also noticed that it's resolving finer detail and there's a lack of colouration in the upper mid/high range. The former point could be the result of the reduced noise floor, and the latter I didn't even notice until I switched to the Go-Vibe; it isn't as apparent when using speakers. Both of these things are probably a consequence of the headphone output being a V-divided feed, directly off the hot end of the power stage. Note that they are nothing to do with the amp not having sufficient power to drive the headphones.

The NAD has the best, non-dedicated headphone output I've used with these cans (HD600s) and I'd probably have stuck with it had I not needed an amp anyway for portable use. Now having used the Go-Vibe I can't imagine wanting to save 65 measly bucks before.

MuFu.

 

[wesbed]

davebot:

I'm in the same situation. I recently purchased a pair of CD3000s (two weeks ago). I didn't like them at first but have to come to begin my apprecation of them in recent days. I'm running the CD3000s through the headphone jack on my integrated amplifier. The CD3000s are sounding better and better the more I use them.

I'm wondering if a dedicated amplifier will make THAT much difference? Could the dedicated amplifier make headphones perform worse (because I'm becoming accustomed to how they sound when run from the headphone jack)? Yes, I'm writing out of ignorance no this topic.

I'm very interested in trying a headphone amplifier. I will most probably wind up purchasing a headphone amplifier as an experiment, a toy, and a hobby. I'd like it, very much, if I discover the headphone amplifier has made a noticeable difference. For now, I'm still wondering.

 

[MuFu]

Quote:

Originally Posted by rsaavedra The Marantz is a tiny bit hazy in comparison (I guess doesn't have as good S/N ratio, or as low a background noise spec), but it's really a tiny bit, and maybe sounds a bit warmer compared to these dedicated amps, but it is punchy and drives the Senn's with ease, musicality, authority and power.

That pretty much echoes my experience with the NAD. Nice.

 

[3lusiv3]

From what I read around here, NAD seem to put decent headphone jacks on their amps.

 

[TonyTripleA]

Well I bought a Perreaux amp and A/Bed it against my NAD surround amp. Both were very good, but I preferred the NAD. Bass had more "impact". Plus for bass poor recordings you can give a little eq.... sweet.

The Perreaux was nice though, but not worth paying extra for "less" to my ears. Both amps had good upper treble to me.

No doubt the Perreaux was probably better suited to higher impedance cans than to my MS-pros.

I'm going to audition some real nice amps soon though... this is after all Head-Fi (or was that wallet-fry?).

Cheers,

TonyAAA

 

[3lusiv3]

I'm not convinced that I should spend on a headphone amp. I use my headphones out of a 10 year old Technics receiver that does a good job. Are you guys just cought up in this headphone thing or are headphone amps really worth it if I already have a receiver? I don't want to order some expensive headphone amp to find a small audio difference. I have seen people here spend alot on headphones and amps only to be disappointed.

 

[john_jcb]

Quote:

Originally Posted by 3lusiv3 I'm not convinced that I should spend on a headphone amp. I use my headphones out of a 10 year old Technics receiver that does a good job. Are you guys just cought up in this headphone thing or are headphone amps really worth it if I already have a receiver? I don't want to order some expensive headphone amp to find a small audio difference. I have seen people here spend alot on headphones and amps only to be disappointed.

By all means don't buy a dedicated headphone amp if you are happy with the jack on your receiver. What you may notice with a good dedicated amp is that you are hearing the source more accurately. I have a Fisher amp that drives headphones quite well but it is definitely darker sounding than any headphone amp I have. The key to good headphone listening is to put together a setup that sounds good to you. It is very easy to get drawn into a whirlpool of spending and upgrades that result in very small improvements in the sound. I am a fine one to talk as I have been down that path as you can see from the list of equipment I have. One thing that I can tell you is that I think that the source is where you can achieve some real improvement. A good player can add significantly to your enjoyment of the music.

 

[mkmelt]

This has been debated many times. The bottom line is there are good, mediocre, and bad sounding integrated amplifiers and receivers (both tube and solid state) and there are good, mediocre, and bad sounding headphone amplifiers out there.

When you find, through trial and error or word of mouth, that a particular headphone and amplifier are a good match, if the amplifier or receiver happens to be an older but very high quality solid state unit such as a Marantz unit, you will be saving hundreds of dollars over purchasing a dedicated headphone amplifier and still have very fine sound.

At one time, receivers and integrated amplifiers did not have headphone jacks as headphones were not in common usage. When headphones came on the market, if your amplifier did not have a headphone jack you could purchase a coupler box that was installed between your speaker terminals on your amplifier and the wires running to the speakers.

These headphone coupler boxes would have a cutoff switch for the speakers and one or two 1/4" headphone jacks. These coupler boxes also had a pair of variable resistors (potentiometers or pots) to enable the user to more closely match the headphone level to that of the speakers so switching from one to the other did not blast the listener.

As headphone jacks started to appear on receivers and integrated amplifiers, these circuits included fixed value resistors that would provide a reasonable match in acoustic level between listening with speakers and switching to the headphones. Early headphones were rated as low as 4 ohms and as high as 250 ohms.

As receivers became less expensive to manufacture and sell, features were scaled down or left out entirely. At some point it became cheaper to install an inexpensive op-amp chip to power the headphone jack than to wire a resistor network from the main power amplifier. If you have high efficiency headphones this may provide adequate volume but only mediocre sound quality. If your headphones require even a bit more power than the op-amp circuit can provide, you need to look at getting a dedicated amplifier. Keep in mind that all dynamic headphones, with one notable exception (the AKG K1000 Earspeakers) require far less than 1 watt for maximum output.

As with single ended triode tube amplifiers, the first watt is the most important watt of power. This is especially true of headphone amplifiers. It does not matter if the amplifier is capable of 75 watts per channel at 8 ohms, maximum power output into a headphone impedance of 300 ohms will be at most just a couple of watts. What matters is how well the amplifier performs when connected to a high impedance load in a power range of perhaps 1 milliwatt (1/1000 watt) up to perhaps 300 milliwatt (1/3 watt). Compared to the latest crop of portable MP3 players that can provide from 15 - 30 milliwatts of power, 300 milliwatts is 10X more power. This tenfold increase in power will be perceived as being just 2X as loud as when being driven by 30 milliwatts. Hard to believe so much fuss is being made over so little amplifier power, but then people pay thousands of dollars for triode tube amplifiers capable of just a couple of watts of peak power.

From personal experience, the Marantz receivers and integrated amplifiers from the 70s work very well with the high impedance phones from Sennheiser, Beyer Dynamics, and AKG. If you like Grado headphones, look elsewhere as the 32 ohm impedance of Grado phones is not a good match for these amplifiers. Less than $100 in vintage Marantz amplifier or receiver will purchase about $300- $400 worth of amplifier in terms of sound quality. The Marantz units also have many more inputs, controls, and outputs than a dedicated headphone amplifier. To be sure, you can buy a better sounding amplifier, but it will cost several times what the Marantz will cost.

 

[Dusty Chalk]

Quote:

Originally Posted by ampgalore If the headphone jack sounds good enough to your ears, then save the money, don't buy a dedicated headphone amp.

And this coming from someone whose moniker is "ampgalore".

No, seriously, I second this motion -- if you're happy, then stop, listen to the music, and don't look back.

 

[Unclewai]

davebot, you are not alone.
I am perfectly content with using my integrated amp's headphone out to drive my dt880. I tried to use a meta42, pimeta, cma47 to drive them before, and they were no match with my a-35r's headphone out.
May be it's just an isolated case where the DT880 prefers headphone out of speaker amp or I haven't experienced enough with high $$$$ headphone amps.

 

[rsaavedra]

Quote:

Originally Posted by mkmelt From personal experience, the Marantz receivers and integrated amplifiers from the 70s work very well with the high impedance phones from Sennheiser, Beyer Dynamics, and AKG.

Wonder if the recent Marantz A/V receivers kept the same basic design philosophy for their headphone jacks used in those vintage receivers. I'm soon going to replace the stock cord of my Marantz SR4000 (3 year warranty about to expire anyway), so I'll open it and will take **** pics near the headphone jack and will post, so that people can provide their insights about what they seem to be like.