[pp312]

Quote:

Really? There was a thread on Head-fi where the OP sent emails to various receiver manufacturers, including Pioneer, Denon, Marantz..., it turned out that the headamp section for most of them was directly coupled the main output.
 


 

That's pretty much a given, with a few exceptions. For instance the higher end Cambridge amps employ a separate class A headphone amp, though their bottom feeder model, the C340A, doesn't. Frankly, I see no reason to use a separate amp. If the main amp is well designed, a couple of step-down resistors will make it just as suitable for headphones as for speakers--at least, for higher impedance headphones. There's still a slight cloud over the lower impedance models, but in my experience the worst effect of impedance mismatch is nothing more than a slightly loose (or over generous) bass. 

 

[khaos974]

Actually, provided the amp can provided enough current, shouldn't the output impedance of the headphone amp be as low as possible to keep a good dampening factor regardless of the impedance of the headphone, in that sense, a high impedance headphone would be more likely not have to face impedance mismatch issues.

 

[pp312]

Most integrated amps' phone jacks have an output impedance of around 220ohms (though Yamaha quote 320). I've never experienced any problems with numerous different phones of impedances from 32 to 300 ohms. And if there is an impedance mismatch, whatever that may mean, I don't believe it has anywhere near the subjective effect that's so often suggested, especially given the pretty wild measured frequency responses of many phones. Damping factor is probably affected most, resulting in a slightly warmer sound which isn't always a bad thing. Bottom line: an integrated amp or receiver can be a good thing, and is certainly better value for money in practical terms than a dedicated amp.
 
Let's hear it for integrateds and (stereo) receivers!

 

[Noobiiee]

Hooking my K701 to the Denon PMA-1500AE of my dad, sound great with some good details and nice punches. 

 

[vinnievidi]

Well, I can honestly say that the HK3490 is not a suitable replacement for a dedicated headphone amp.  It can drive cans like the HD650 pretty well, but there is an annoying static noise in the background that never goes away.
 
I am looking to simplify my setup and get rid of my dedicated headphone amp (since I need a new receiver anyway), I was looking at picking up a Denon DRA-CX3 stereo receiver or a NAD C372 integrated amp.
 
 
There is nowhere in the city to audition the Denon, so I may have to buy it first.  Before I do, does anyone have any experience with this model or the NAD?  If so, would its headphone jack be fairly good at driving the HD650?  
 
 

 

[Noobiiee]

The 1500AE's headphone section seems to be fairly neutral and quite powerful to me so don't think it'll have any prob driving the HD650. From my observation, most of the new integrated amp or pre-amps in the mid-fi markets would have a headphone section that is capable of driving power-hungry headphones (300-600ohm).

 

[vinnievidi]

@ Noobiiee: that's good to know.  Hopefully Denon's quality is consistent with its price.  
 
Last night I went to J&R with my HD650s and tried them out through Denon's DRA-697, which I was told is their top consumer-level 2-channel receiver.  The Denon's headphone performance was infinitely better than the KH3490: cleaner sounding and with more weight in the bass (though I still can't knock the HK's bass definition).  Since the DRA-CX3 is marketed as being in a class above their consumer models (and you said that the 1500AE, which is also above their consumer models, was no slouch either), I took the risk and ordered the CX3.  
 
Once it arrives I'll post my impressions.

 

[ilikebands]

My Yamaha AX-497 is rated at .3v/680 ohms.  I am wondering if this would make buying a dedicated headphone amp unnecessary.  They seem to work great driving my Senn HD650 right now, but when I volume match with an Ipod at 100%, there is not a huge difference in sound. 
 
I also noticed that low impedance phones seem to sound pretty bad when paired with the AX-497. 

 

[lyramax]

Quote:

My 880 600 ohm arrived today and it sounds great with the Onkyo 906.

I should note that I have to turn the Onkyo 906 volume up 2-3 notches (dB) to get the same sound volume on my Beyerdynamic DT-880 600-ohm as I would get with my other headphone Sennheiser HD580.

 

[Noobiiee]

That's why hifi HPs exist. One thing to remember, the hp sect in your turner/pre-amp can also be good or bad. If the pre-amp itself is not up to scratch then neither will its HP section. 
 
Quote:

My Yamaha AX-497 is rated at .3v/680 ohms.  I am wondering if this would make buying a dedicated headphone amp unnecessary.  They seem to work great driving my Senn HD650 right now, but when I volume match with an Ipod at 100%, there is not a huge difference in sound. 
 
I also noticed that low impedance phones seem to sound pretty bad when paired with the AX-497. 

 
 

@Vinnie: the Denon line-up should work well with the HD650 since Denon amps sound sig tend to be quite detail, clean and balanced so should be a good match with the HD650 IMO. With the K701 I find the sound to be more full-bodied with the details and soundstage of the K701 being retained. ADCOM pre-amp's HP section also receives a lot of praises. The vintage GFP-555, which can be found for ~$150 also make a good candidate. 
 

 

[BluFalcon]

No dedicated HP amp for me.  Plug my cans directly into my Yamaha RX-V1800 HTR.  With Straight Analog or Pure Direct everything is just lovely. 

 

[felchi80]

Quote:

No dedicated HP amp for me.  Plug my cans directly into my Yamaha RX-V1800 HTR.  With Straight Analog or Pure Direct everything is just lovely. 

agree.
I've always used my NAD integrated amps from the late 70s to early 90s.
Plus you get to drive your speakers as well!

 

[tlniec]

What if you don't have a beefy 2-channel amp... but say a mass-market 5.1 channel A/V receiver instead.  I'm thinking specifically of the Sony STR-DG510 I bought a couple of years back to drive a modest 5.1 channel bookshelf speakers+subwoofer setup in my home office.  Does anyone know how the headphone outs for this type of receiver are generally configured?  Are they still resistor-coupled to the L+R mains?  Or is it more likely a separate circuit?  Also, from a DAC standpoint, would an inexpensive outboard DAC (thinking something like a Fiio E7) likely outperform the receiver (it looks like it has RCA outs available)?  I doubt anyone is that deeply familiar with this specific receiver, but I guess I'm thinking of this class of receivers in general.

 

[khaos974]

I read that whether the headamp is resistor coupled with the mains depends more on the amplifier model that the brand or any other criteria, in other words, it's impossible to know without opening the amp.
As for the quality of the DAC, I'd guess it's at least as good as an E&, while they are not the topmost priority on the conception of the receiver, it's likely that economy of scale enable manufacturers to pack more quality than the price suggest.
 
PS: Cursory comments, just points to think about.