[stratowhammy]

I just want to start this post by thanking all the members who have helped me make decisions in the past, and who have guided me in the right direction.  I have learned so much by reading through head-fi posts and I hope to learn more from those who respond to this post.
 
I am looking for a good pair of headphones that would pair well with a ZERO DAC/AMP.  My source is my MacBook outfitted with Amarra (all music played is lossless) to the ZERO DAC/AMP via S/PDIF.  I want to know if anyone who has this DAC has any preferences for open backed headphones that work well with this DAC/AMP.  I am currently using a pair of Beyerdynamic DT-770 PRO closed backed cans, which are nice, but I feel that the sound stage is not as wide as I might like.  I don't know if this is because of the amp or the cans.  I know that the ZERO DAC/AMP is not a top quality amp by any stretch of the imagination, but I noticed a marked improvement when I switched from USB to S/PDIF.
 
Basically what I want to know is, can I expect an improved sound stage with a different pair of headphones?  Will openback help, or is the amp the limiting factor here?  And what open back headphones do people have experience with out there that they really like paired with the ZERO DAC/AMP.  I know that pairing is important, my Shure SR-800s are only 40 ohm impedence and so you can't turn it up real loud which results in a lack of balance between the left and right. The Beyerdynamics just sound better with this amp (but not with my e7 ---> yes, I know, another cheap amp...)
 
Thanks for your input.

 

[Mad Max]

You could try ATH-AD700, I guess.
I think a better amp/DAC would give you the improvement you're looking for with your current headphones.
 
The channel imbalance with the Shures is the volume pot's fault.  Are you using the lowest gain setting with it?  If the gain is too high, it becomes difficult to avoid the channel imbalance at the lower volumes.

 

[stratowhammy]

thanks for the suggestion.  i've looked at these headphones a lot.  you know, I don't think there is a way of adjusting the gain on the zero dac/amp, but im going to tool around it and see... it may be the one of casualties of having a cheaper lower end dac/amp.  I was also looking at AKG K702s, but the impedence again is lower on these cans as well (62 ohms).  Others on head-fi have recommended these and reported an incredibly expansive sound stage for cans under $500.

 

[Mad Max]

K702 is a junkie for current, and I doubt that Zero can provide enough.  You should probably stick to low impedance headphones with 98 spl and up.

 

[stratowhammy]

I still have trouble understanding exactly how ohms, voltage and wattage all still interact when it comes to headphones.  The Zero Dac/Amp drives my Beyerdynamic DT 770 Pro 250's just fine, and is too strong for my Shure SR-840s that have a 44 Ohm impedance.  I did the math and the Beyer's require something in the range of 5 volts to drive properly, the Shures supposedly require in the range of 6 volts, the 702s only require 3.2 volts to power them appropriately (if my math is correct) so shouldn't the Zero Dac/Amp power the 702s just fine if it powers my Dt 770 Pros?  I also ordered a modified Dot I+ hybrid, I understand that it works well with lower impedance headphones, I would think that 62 ohms is still lowish in the grand scheme of things (30-600 ohms).
 
Let me know if my reasoning is either missing something or just completely off.  thanks.

 

[Mad Max]

From what I've read, lower impedance headphones require more current than voltage to drive properly and higher impedance headphones require more voltage than current.
Yeah, 62 ohms isn't very high.  A headphone's impedance should always be higher than the amp's output impedance, or else trouble.  Impedance has more to do with the transfer of power.  Headphones with lower spl like K702 tend to require a lot of current.  I think I should get off my lazy butt and look this stuff up in detail, lol.

 

[wdahm519]

Well. I = V/R
 
I = current
V= voltage
R = resistance (ohms)
 
Soooo... since R, the resistance, is a constant in this equation - but different for each headphone, but in this case we can keep it the same.  From the equation, the more voltage supplied for the given constant resistance, the more current you're going to have flowing through your cans.  If I understand it correctly, the more current - the better it sounds.
 
Therefore, a can with higher resistance obviously needs more voltage to get the same amount of current though the cans.  You can fill it in with your own numbers.

 

[dlaloum]

Don't forget that Power (watts) = Volts x Current...
 
And that how sensitive a set of headphones is is measured in Decibels Sound Pressure Level per Watt
 
So you can have an inefficient or efficient set of HP's at any particular impedance. But the requirements to drive HP's properly vary a bit based on the impedance....
 
Sp 600 ohm HP's will require less current and more voltage for the same resulting power and vice versa for 32 ohm hp's
 
Just because they have high impedance doesn't mean that they are a difficult load - it just means that if the Amp driving them was optimised for max current rather than voltage - you probably won't get best results.
 
Course some of the better amps can drive both extremes very well as both their current and voltage capabilities cover the requirements of a very wide range of HP's.

 

[wdahm519]

Yes that's true.  I did forget to throw that relationship in with my post.  You are right.
 
Good observation.