[matsuba]

Hi, I've been lurking around here on and off for a while now and have finally joined tonight.
 
I've been getting into headphones since the arrival of our first son 3 years ago. I won't go into what gear I've had (and sold) in this time apart from to say what I'm running at the moment.
 
I use my iMac running Spotify and iTunes which is plugged into my old Kenwood hifi amp aux input into which I plug my AKG Q701's in the headphone socket.
 
I've read a lot about how the Q701's need a headphone amp to drive them properly. I've always thought my Kenwood would do as good a job as anything else until, as an experiment I plugged my phones into my iphone and played the same track through Spotify and noticed no difference!
 
So maybe I do need 'proper' headphone amp after all?
 
Next I tried a comparison between my AKG's and a pair of old Sennheiser PX200's into the Kenwood and WOW...what a difference! The 200's were so much louder and fuller (though less detailed) than the AKG's. I'm guessing it's because the are easier to drive, being smaller etc? I compensated with the AKG's by turning up the kenwood so the volume matched. Is this all a dedicated headphone amp will do too? Make it louder? It's killing me knowing I'm probably not getting the most out of these beautiful headphones and I need to do something about it.
 
So DO I need a headphone amp? Would I be better off spending my money on a USB DAC and keep the Kenwood turned up? Would something like the Arcam rPac solve all my "problems" by getting a better initial sound from the source and also amping the 701's at the same time? Money is tight so I can't spend a fortune on a wrong decision.
 
Any advice or opinions would be greatly appreciated!

 

[andrewberge]

I don't think you need to upgrade anything at all
All headphones sound different, and will output different volume levels with the same amount of power.
Also, headphones make the biggest difference in sound. Waaaay more than the amp or the DAC.
In fact, there's some debate on whether today's amps and DACs make any audible difference at all.

 

[ProtegeManiac]

Quote:

 
Next I tried a comparison between my AKG's and a pair of old Sennheiser PX200's into the Kenwood and WOW...what a difference! The 200's were so much louder and fuller (though less detailed) than the AKG's. I'm guessing it's because the are easier to drive, being smaller etc? I compensated with the AKG's by turning up the kenwood so the volume matched. Is this all a dedicated headphone amp will do too? Make it louder? It's killing me knowing I'm probably not getting the most out of these beautiful headphones and I need to do something about it.
 
So DO I need a headphone amp? Would I be better off spending my money on a USB DAC and keep the Kenwood turned up? Would something like the Arcam rPac solve all my "problems" by getting a better initial sound from the source and also amping the 701's at the same time? Money is tight so I can't spend a fortune on a wrong decision.
 
Any advice or opinions would be greatly appreciated!

 
As much as older receivers tend to have a more suitable headphone driver than most devices today, especially surround receivers*, there could be a lot of factors other than the efficiency of the headphones. The amp could have a high impedance, and the PX200's sensitivity might just be high enough to hide that. Or the gain could be too low, in which case it's really more a problem with resulting volume with the Q701's efficiency than amplification quality. If aside from the PX200 being louder the Q701 sounds a bit anemic (ie, lacks dynamics), chances are you do need a better headphone amp.
 
Get a device that integrates a decent DAC and headphone amp in the same box, with a decent power supply design (not necessarily one with two transformers in it, as high-end speaker receivers might have). Check the thread for the AudioGD NFB15 if it matches well with the Q701. From my own listening though the Burson Soloist was the best amp for the Q701 - the sound was incredibly smooth and fast, with a lot of weight on the bottom end and depending on the source, a lot of treble extension too. However, that thing costs over $1,000, and personally no matter how much I enjoyed it I couldn't justify the performance improvement with the added expense over the $400 I paid for my Meier Cantate.2 (got it used), not to mention I kind of didn't like the Soloist on the HD600 (which I had, and it was warmer in the midrange vs the Cantate, even if the same DAC or CDP was used through their analog inputs). On low gain you had to put it at max volume, but it's no slouch - on the K701 I'd say it's about 90% of the Soloist's performance on the Q701, and as I bought it, 40% of the price.
 
Also, devices like the NFB15 are relatively compact, so you can just put your receiver where you can set-up speakers - even if it'll be in the same room, if your listening position isn't at the same spot, then at least you might not need to have its volume knob within easy reach while on the computer. They also have analog outputs from the DAC section so you can still use its quality DAC circuit for the speaker set-up. Mind the gain settings if you plug in the PX200 though, as you might use Hi on the 701.
 
 
 
*CDPs are another matter - by now, if they have a headphone amp, they tend to actually be usable, not like one of my old Onkyos at a time when only Marantz and Sony seemed to have consistently decent headphone outputs on their CDPs. Based on some reviews I ran into before, if you still listen to CDs but are using or about to transition to headphones, their good CDPs can stave off buying a headphone amp for a while.