True Headphone AMP?

Not sure that using an ordinary amp would be a good idea in most cases. Keep in mind that dynamic headphones typically produce in the rough area of 100db spl for an input of 1 MILLIWATT (0.001 watts).

Also, a low powered tube amp (or any other tube amp that is designed to drive speakers) would not be a good choice because the higher impedance of the headphones (compared to speaker impedances) would not properly load the amp.

Regards,
-- Al

Al & Elizabeth or other members who have experience with this.

How would one hook up their amp so that it could power a pair of headphones? I have a Hafler DH-220 and from looking at the manual it says it can be used to power a set of headphones. From looking at the Hafler and seeing a lack of a headphone jack and just conventional speaker terminals I haven't the faintest idea as to how to hook up headphones to it. I was thinking about using the Hafler DH-220 as a headphone amplifier since it is just lying around unused right now. The preamp I plan to use in this set-up doesn't have a headphone jack. The headphones I plan to use are either the AKG 701 or Sennheiser HD580s.

Thanks so much for starting this topic Nikturner920. I've been curious about this topic for some time now.

The only headphone I know of that can be driven directly off an amplifier is the AKG K1000 which has been discontinued for many years. Very unconventional in appearance and design but still only requires 5-10 wpc to operate properly. They are spec'd at 104 dB SPL with 1000 milliwatt (1 watt) input. Remember, those drivers are still VERY close to your ears, and each halving of distance from a point source increases SPLs by 6 dB. So if your normal listening distance is 8', by the time you get to 3" you are at a 30 dB increase in volume for the same output from the amp, assuming of course equal efficiency. Bottom line is with your Hafler you would be operating in the very non-linear portion of any attenuator's range, where channel tracking is typically poorest, distortion is highest and volume increases are logarithmic, and you would have an extremely difficult time adjusting the volume. So the K1000s work w low wattage tube amps, and due to their high impedance and unusual design, they require the most power of any headphone I know of. They do sound fantastic but given their replacement cost and difficulty in finding spare parts, I'd think very carefully before hooking them up to a high powered amp.