[steelstring41]

I have music playback off of a dedicated PC with a Sony AV receiver hooked up via HDMI. Then I just use my Shures to listen through the receiver's headphone jack.

So here is my question: Is the receiver doing me justice with this playback method? I realize that the Shure 1440s are low impedance (37 Ohms) and do not exactly need the extra power, but I wanted to avoid jacking straight into my PC because of the onboard noise junking up the signal.

Would it benefit me to switch to another setup like an external DAC/AMP combo, or would that be considered a waste of money? I'm just worried that the headphone amp within the Sony receiver isn't pushing the Shures to their potential...

A little bit of info:

PC with i7 860 w/8 gigs RAM running JRiver (WASAPI audio path) to a Sony STR-DH710 receiver through HDMI connection
Shure 1440s plugged into receiver
Receiver side EQ is set to neutral ('0' setting for treble/bass etc)
All music is in FLAC ripped from CDs, with a few high-res tracks that are 96/24 bit

Any and all input or advice is much appreciated!

 

[PurpleAngel]

Chances are the Sony's headphone output jack has a high impedance (50-Ohm, 75-Ohm, 100-Ohm ?)
Technically your 37-Ohm headphone might (should) do a little better with a headphone amplifier that has a output impedance of around 5-Ohms or less.
FiiO E10K USB DAC/Amp, $75, comes with a output impedance of under 1-Ohm

 

[steelstring41]

Chances are the Sony's headphone output jack has a high impedance (50-Ohm, 75-Ohm, 100-Ohm ?)
Technically your 37-Ohm headphone might (should) do a little better with a headphone amplifier that has a output impedance of around 5-Ohms or less.
FiiO E10K USB DAC/Amp, $75, comes with a output impedance of under 1-Ohm

Thank you for the reply, it's been difficult trying to find a spec on the output jack of the AV receiver. This would tell me exactly what the output impedance actually is. If what you're saying is correct, I'll definitely be checking out that FiiO you mentioned. Are there any other amps available that you would recommend that fit into that low-Ohm spec I'm looking for? Again, thanks!

 

[PurpleAngel]

Thank you for the reply, it's been difficult trying to find a spec on the output jack of the AV receiver. This would tell me exactly what the output impedance actually is. If what you're saying is correct, I'll definitely be checking out that FiiO you mentioned. Are there any other amps available that you would recommend that fit into that low-Ohm spec I'm looking for? Again, thanks!

 
I'm guessing a lot of A/V receivers do not publish the headphone output impedance because it would not be a flattering feature to brag about.
250-Ohm headphone like the Beyerdynamics would be a good headphone for use with receivers
 
You could try an Asus Xonar DG or DGX sound card, they are low cost, come with a basic head amp and Dolby Headphone.
Can't be sure if it will not have the same issue as the on-board, or maybe not as much of a noise issue, or may have no noise issues at all
My Chrystal ball is out being polished right now, so I can't look into it to have it tell me exactly what is causing the noise junk.
 
Where as the E10K is all external, so it should not have the junk noise issue.
There is the FiiO E17 ($140 new) as it comes with S/PDIF connection, it would allow you to work with the on-board audio's features (without the noise issue).

 

[steelstring41]

I'm guessing a lot of A/V receivers do not publish the headphone output impedance because it would not be a flattering feature to brag about.
250-Ohm headphone like the Beyerdynamics would be a good headphone for use with receivers

You could try an Asus Xonar DG or DGX sound card, they are low cost, come with a basic head amp and Dolby Headphone.
Can't be sure if it will not have the same issue as the on-board, or maybe not as much of a noise issue, or may have no noise issues at all
My Chrystal ball is out being polished right now, so I can't look into it to have it tell me exactly what is causing the noise junk.

Where as the E10K is all external, so it should not have the junk noise issue.
There is the FiiO E17 ($140 new) as it comes with S/PDIF connection, it would allow you to work with the on-board audio's features (without the noise issue).

I think you're probably right on the ball with the idea that they don't publish those specs due to their (presumably) low quality build. I love the sound quality of my 1440s but sometimes wish that I could also try out a really power hungry phone like the Beyer you mentioned. I wonder why Shure chose to go low-Ohm on a headphone in this price range, with similarly priced sets in that bracket usually having much higher impedance. I can only speculate on that, or maybe someone else has some insight. I've read that Ohms don't usually directly correlate with sound quality.

I would try a new sound card but I just don't really like the idea of onboard sound. I'm more than willing to upgrade to an external headphone amp to replace my receiver if I can be convinced that there will genuinely be a noticeable difference in fidelity.

One other thing I may have forgot to mention is that my PC, despite having a more than generous motherboard for music playback does not seem to have either optical or coax out. Do the FiiO amps which use USB have that port solely for power source, or can the audio path + power go through USB? I see coax connections on many of the external units and this wouldn't end up being compatible.