[mireque]

Everything seems fine now.

 

[Adda]

The opinions on the K701/2 in the studio ranges from them being useless to perfect, in my opinion the K701/2's are flawed and are not suited as a reference point.
From what you write about your K702 it would seem that they are indeed under amped and yes and amp should improve things quite a bit, you can't power a pair of hard to drive headphones with a soundcard.
Beware though that lot of people, including musicians, agree that the K702 to have a plasticky midrange, a treble spike and an artificial soundstage, so they can't be trusted.
I make electronic music my self and have done so for about 10 years (I use K240DF's), I'd recommend K271mkII over K702 any day.
The K702 is a hifi headphone with fancy studio words written on it, the K271mkII where designed for studio use from the beginning.
 
But back to your question, driving 62 ohm headphones out of a 75 ohm output is not good, you need the output impedance to be lower then the headphones impedance or it will not sound right (dampening trouble).
You need a low an output impedance as possible (5 ohms or less).
You say the K702 sound "glued together", I think that's what I call "congestion" and is a sure sign of poor amping, especially if it gets worse at higher volumes.
As for what amp to get I donno, maybe Acix knows, he also uses K702's for studio work.

 

[Redcarmoose]

I have had the K-701s for a couple of years now. They are really fun to listen to electronic music on. Electronic music is different than stuff recorded with a mic. If I was to guess I would think that under amped mixes with the K-702s would end up sounding bass heavy on other stereos. I did computer audio and home recording for awhile and even though I read a lot of books, it never went any farther than a hobby. It was always stated to play your mixes on a number of systems after you were done no matter what equipment you used.
 
I think there is a small difference in views regarding equipment for high-end headphone audio and mix-mastering. Most people I know who demo music believe it or not play it in their car! They just get given demo CDs and they don't want to sit and listen to them so they play them in their car driving somewhere. If they pass that test then they go on from there!
 
A correct recording of music will play well in a number of stereos. Every single recording out there seems to have a little different sound. Some recording studios end up having a house sound that you can identify in their recordings. This goes for producers as having a set of headphones that they end up liking. I have heard of all kind of interesting headphone amps custom made for studios and by hearing about them I am sure they all had a different sound. One studio I heard had one custom made from a guitar tube head amp. So even though there are rules there are also people breaking the rules and getting good results.
 
You need to have trust in your system and I would say that unless you get to a preset that seems to work and sound correct on many systems your un amped k-702s are going to make you push the sliders heavy on the lower mids and bass to get to a natural sound. Audiophiles are also looking for a sound signature and authority with getting a powerful amp for the k-702s. I don't know what would make your mixes sound compressed with using the k-702s? I did find that with my home mixes that an undercompressed sound or over compressed sound was easy to fall into and getting it right is really an art. It is easy to make a super compressed recording as everything just gets the bass taken out. It is an art to make everything be in it's own little place in the mix without having the bass take over at times or have the high mids get too screachy sounding in places. It would be interesting to get some pointers from real studio people and find out if they use the k 702s and what amp they use. I don't think it would be good to try and mix with them underpowered. 

 

[Adda]

^
With electronic music you can only make what you can hear, because you design the sound your self.
So an amp for those K702 is a must if they are to have any merit when designing sound.

 

[mireque]

Thank your for your comments.

 

[mireque]

And definitely, when compared to my old $15 budget Philips SHP1900 headphones (which I consider quite flat but muddy), you can really tell the difference.

 

[Adda]

By under amped signal I mean that if the amp does not output a signal strong enough to control the headphones accurately they will not perform well.
A headphone amp may be able to drive a pair of headphones to loud volumes, but it has to sound good when doing so.

 

[Acix]

The RME weak point is the hp amp, and is not only with the AKG's is weak with most of the hps out there. In the past I had the RME Digi 96/8 and was the same...last week I checked the Babyface (baby on the face) that sounds like a Chinese knockout. I can recommend you to start with the Meier headfive for around 160- $180 used on the FS forum, for a the better options check out the SPL Phonitor / Auditor. I use the K702 with the Apogee mini DAC and the Adam A7 combo, no major complaints but I know I can go better with one of the SPL's.

 

[Adda]

Quote:

The RME weak point is the hp amp, and is not only with the AKG's is weak with most of the hps out there. In the past I had the RME Digi 96/8 and was the same...last week I checked the Babyface (baby on the face) that sounds like a Chinese knockout. I can recommend you to start with the Meier headfive for around 160- $180 used on the FS forum, for a the better options check out the SPL Phonitor / Auditor. I use the K702 with the Apogee mini DAC and the Adam A7 combo, no major complaints but I know I can go better with one of the SPL's.

There you go!

 

[Chris J]

Basic electrical theory states that the output impedance of your voltage source (i.e. the headphone amplifier) should be 10% or less than that of the load (i.e. your headphones). Since your headphones have an average impedance of 62 ohms, you should select a headphone amp with an output impedance of 6 ohms or less. The Lehmann Linear headphone amp has an output impedance of 6 ohms, the Matrix M Stage has an output impedance of 1 ohm.
You want a low output impedance because you do not want the output impedance to react with the load impedance and give you frequency response errors. In addition, a lower output impedance will give you better damping factor, i.e. better control over the headphone voice coil. There are other brands of headphone amp that will do this. Also make sure the amp will output enough current and voltage, so you are looking for a spec of approx. 100 mWatts @ 60 ohms, or approx. 100 milliAmps & 5 volts RMS.