Amping for AKG Q701
Mar 18, 2012 at 8:26 AM Post #167 of 508
Quote:
what about E11 with Q701? thanks


The E11 should work well, except the maximum power is not very high (it is enough for 107-108 dB max. SPL with low distortion, though). The best of the "cheap" amplifiers for the Q701 is most likely the O2.
 
 
Mar 18, 2012 at 9:53 PM Post #168 of 508
I recently ordered a set of q701s. Since I've ordered them I've been reading about headphone amps. I've read enough to know that the 70x series like current. That has lead me to the LD I+. I am thinking that is the best bang for them buck amp for the 70x series. I am thinking about just ordering one but I would like some more feedback first. What do you guys think of the LDi+ and the q701s? Seems like a perfect match from everything I've read so far.
 
Mar 18, 2012 at 11:10 PM Post #169 of 508
I recently ordered a set of q701s. Since I've ordered them I've been reading about headphone amps. I've read enough to know that the 70x series like current. That has lead me to the LD I+. I am thinking that is the best bang for them buck amp for the 70x series. I am thinking about just ordering one but I would like some more feedback first. What do you guys think of the LDi+ and the q701s? Seems like a perfect match from everything I've read so far.


My Q701 does very well with my LD I+, they're a tight match. I'd say quite fun and musical.
 
Mar 19, 2012 at 2:07 PM Post #170 of 508
I am debating about just ordering the LDi+ now.  I haven't received the Q701s yet but they should arrive this week.  I plan on using it with my computer, which has a Asus Xonar DG sound card, for casual listening.  The majority of my listening will be using my home theater setup with an Onkyo 886 preamp.  I don't have an external dac yet but I will look into one down the road.  I still listen to discs, sacd, bluray audio, cd, etc.  I very much doubt the headphone output of the 886 will be able to power the q701's properly.   
 
Mar 19, 2012 at 2:38 PM Post #172 of 508
Gamma 1 dac, is ideal (there are a few commercial builders). I also think the HRT MusicStreamer 2 is a great bargain, and the Grub dac, if you just need a basic USB dac and don't mind some DIY. 
 
Mar 19, 2012 at 3:11 PM Post #174 of 508
Ok - once again, you are suggesting products 3-5x more expensive than the requestor (or anyone else thus far but you) has ever indicated being willing to deal with or suggested.
 
He's going with the 02 as an amp, my guess is he does not want to top $300 for an amp + dac combined. 
 
Mar 19, 2012 at 3:26 PM Post #175 of 508
HRT Music Streamer II ($150) + O2 ($150) = should be a potent combo for $300.

Or, HRT MS II with LD I+, same price.
 
Mar 19, 2012 at 5:43 PM Post #176 of 508


Quote:
Gamma 1 dac, is ideal (there are a few commercial builders). I also think the HRT MusicStreamer 2 is a great bargain, and the Grub dac, if you just need a basic USB dac and don't mind some DIY. 



X2 for the gamma 1. Recently had one built by Mr.X  and I'm very happy with it....for the price I doubt there's anything that can compete with it. Combine that DAC with the O2 and you'd have a good budget set up for not much over $200. Never heard the O2 myself though, to be honest.....only going FWIR.
 
Mar 19, 2012 at 6:29 PM Post #177 of 508
 
 
Can you suggest a dac to go with the O2 for the Q701?
 


Depending on what digital inputs you want, one of the iBasso products should work for you.
The iBasso products can be battery powered and are very small too.
I use an iBasso D12 when listening to music off my notebook.
It can even drive a Q701 directly when you are travelling light.
 
Mar 20, 2012 at 7:53 AM Post #178 of 508


Quote:
So,  back to the topic of amps for the 70X ....will this phase shift that's been discussed be audible or not with the two budget amps that were being discussed, the E9 and the O2? Would I likely notice it with the ld mkV or something else in the $300 price range? Can I rest easy knowing that the ld mkV isn't producing audible frequency deviations or phase shift? What about the E9? I'm leaving aside the noise issue since I don't hear any on my set up.



Since no one else has answered;
This frequency dependent phase shift has been argued to death in various forums thru the years. 
To avoid this type of phase shift, you would us an amp with widest possible bandwidth, for example, -1.0 db @ 100 kHz would lead to very little high fequency phase shift in the audio bandwidth.
One thing to keep in mind:  distortion, phase shift, frequency deviations,etc. are all cumulative.
For example, if you have a DAC which is 0.3 dB down at 10 kHz and an amp which is down 1.2 dB at 10 kHz then when you use them together you are 1.5 dB at 10 kHz.
Same goes for distortion, when you are listening to headphones & amp & DAC combination you are listening to the cumulative distortion of all three pieces.  You could argue that the headphones are distorting the distortion from the amp which is distorting the distortion from the DAC!
 
Regarding the noise floor thing (I'm not referring to hiss), anyone notice their sound system sounds better at 3:00 a.m?
 
 
 
Mar 20, 2012 at 10:26 AM Post #179 of 508
The specs for the LD mkV doesn't show 'bandwidth', AFAIK. Here's what you get from the manufacturer: http://www.littledot.net/forum/viewtopic.php?f=3&t=142&start=0  According to his specs it should be flat to within .5 dB. But wouldn't that depend upon the headphone used?
Here's the e9 specs....nothing about bandwidth here either: http://www.fiio.com.cn/product/index.aspx?ID=19 Will the specs for either show how well they will pair with the phones in question, the Q701? The E9 has a fairly high output impedance according to navguy's review....he claims it's not ideal for low impedance headphones. The mkV manufacturer refused to answer when he was questioned about the output impedance of the MKV on the LD forum. I wonder why that is. 
Quote:
Since no one else has answered;
This frequency dependent phase shift has been argued to death in various forums thru the years. 
To avoid this type of phase shift, you would us an amp with widest possible bandwidth, for example, -1.0 db @ 100 kHz would lead to very little high fequency phase shift in the audio bandwidth.
One thing to keep in mind:  distortion, phase shift, frequency deviations,etc. are all cumulative.
For example, if you have a DAC which is 0.3 dB down at 10 kHz and an amp which is down 1.2 dB at 10 kHz then when you use them together you are 1.5 dB at 10 kHz.
Same goes for distortion, when you are listening to headphones & amp & DAC combination you are listening to the cumulative distortion of all three pieces.  You could argue that the headphones are distorting the distortion from the amp which is distorting the distortion from the DAC!
 
Regarding the noise floor thing (I'm not referring to hiss), anyone notice their sound system sounds better at 3:00 a.m?
 
 



 
 
Mar 20, 2012 at 11:01 AM Post #180 of 508
Quote:
Here's the e9 specs....nothing about bandwidth here either: http://www.fiio.com.cn/product/index.aspx?ID=19

 
It has been measured, however, and you can see the response on this and this graph.
 
Quote:
The E9 has a fairly high output impedance according to navguy's review....he claims it's not ideal for low impedance headphones. The mkV manufacturer refused to answer when he was questioned about the output impedance of the MKV on the LD forum. I wonder why that is.

 
Well, someone who has the MKV could measure the impedance then. It does not require expensive equipment.
 
 

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