Question

I use AKG Q701 headphones which are known to need a good amp for them to drive/perform at their best.  The headphones have an input impedance of 62 ohms, 105dB sensitivity, and a max power rating of 200mW.  I use a Presonus Studio 68 which has headphone outputs that have an impedance range up to 300 ohms and power rating of 150 mW@56 ohms.  That seems fine to drive the Q701’s without buying a headphone amp and they sound fine to me, but I was curious if anyone who knows about such things can provide an actual reasoned opinion on the matter.

Thanks in advance.

Answer 1

Impedance can be a bit tricky to explain.  I usually start with a fair article.  Understanding Impedance from Sound on Sound is a good place to start.  You might also search for other articles specifically dealing with headphone impedance.

Personally, if your headphones sound fine to you, then that's all that matters.  I'd say if you had an issue, then you would know.  The sound would be very thin and the volume low.

Answer 2

Power rating of the headphone amp in studio 68 is 150mw PER CHANNEL;

but anyway, don't be lost seeing only these plain numbers. I can say the st 68 has hp amps

so loud (and loudly clear) I've never ever heard such on any other usb audio interface on the market.

They marketing say it's ear-bleeding... I can definitely it is deadly :-) I'm sure it will drive your AKG.

The only complain I have about it that you can't adjust the mix... it is factory set to 50-50% (input/DAW)