True Headphone AMP?

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.

The headphone amp of your choice would be a better approach than your Hafler. ..better sound, easy connection, etc. Look at Headphone.com

Antique sound lab UHC signature amp to headphone converter may work.

Go browse around Head-Fi. Lots there.

I run a Sonic Frontiers Line 3 that Bill Thalmman did his magic (and it is magic) and retubed it with NOS Siemens CCAs and E88CCs. I love this preamp - this mod/retube took a very good preamp and made it great.

The Line 3 has a SE headphone jack which I used for a while. After reading tons and exchanging e-mails with Head-Fi members, I auditioned a Rudistor RPX-33 (now the RPX-35 due to a few minor updates), a dedicated, SS, SE head phone amp. I run it from the tape outs on my preamp.

The unit never went back. The improvement over the Line 3 head phone jack is immense.

There are several very prominent, quality head phone amp manufacturers (SS and tube) out there. It tends to be kinda boutique - even more so than big rig hi-fi.

Good luck.