Headphone Envy - AKG K 701

Anyone tried it out yet?

no, because just like the k-240s, the pads are round rather than oval, and will begin to pinch your ears after a few hours of use. i hate that.

Only 62 ohms? Those aren’t real AKG headphones. Real AKG headphones have 600 ohms and require a separate power amplifier. :p

yeah. max volume on my ipod is just about right for a 600 ohm pair of cans.

If I could afford an amp to drive that :p

But even at 62 ohm impedance these do require some sort of amplifier. I’m probably cheaping out and getting one of the Headroom Bitheads or a Gilmore Lite.

I haven’t tried pair yet, they’re not widely available, so definitely noted. Worst case I’ll try both the 701 and the Beyerdynamic DT880s returning the one I like less.

Any audio source should be able to drive 62ohm headphones to hearing-loss associated energy levels, so I can’t think of a sane reason to amplify a signal meant for low impedance headphones other than for the built-in crosstalk filter* that a lot of them pack. Or maybe if you want some equalizer functions.

  • mixes the left and right channels a bit so that your brain isn’t shocked by the unnaturalness of a left-ear or right-ear only sound source.

Oops! Actually, I can think of one: to save ipod battery life. The ipod bud headphones are 32 ohm impedance. The 701 cans have almost twice the impedance, and thus require almost twice as much power to drive at similar volume.* Although, the difference in sound energy between the two headphones with the ipod at max volume will only be -3dB.

So, you suck up power from the headphone amp batteries (which you can get at a supermarket) instead of from the ipod (which requires a charger).

    • depends on the sensitivity of the ear bud headphones, but for simplicity just assume they are the same as the 701, 105dB/mW.

edit:
I’m geniunely curious now as to how much voltage can be sent out the iPod headphone jack. Using ohms law ( watts = volts^2 / ohms), we can figure out how many milliwatts of power hit the 701s. I mean, with these cans, you only need 0.01 mW to generate 85dB of sound. I bet an iPod hits that rather quickly.

I can make an .mp3 of a 1khz sinewave and use that in the calculations (would I measure that as V or Vrms? I forget.) When I have free time (during GDC), I’m going to borrow a multimeter from the guys upstairs and run some tests. :-)

You want to use those huge luxury headphones on an iPod? I don’t get it… you can’t really walk around with these things, and surely you have a better audio source at home?

Well, i was trying to think of a good reason for wanting a headphone amp to drive high-efficiency headphones, and “conserve portable player battery life” was the only one i could come up with.

That got me curious about ipod power consumption, etc.

To answer your question, though, yes I would use them on an iPod. I’ve actually relegated my old AKG 240m’s to iPod duty at work (hence my not-comfortable-for-long-use comment). There, I don’t have a better audio source.

I do walk around with them. After a grueling all-nighter, there’s nothing more rewarding than standing in front of the picture window to receive the first warming rays of the new day’s sunrise upon your face while listening to Strauss’s “Also Sprach Zarathustra”. :-)

I ended up ordering the less expensive K601s, they’re nearly the same in size and form. The Pads were advertised as new design for the 601/701. They are actually round, the donut hole is 2 1/2 inches in diameter and the pad is an inch across. I’m finding them quite comfortable.