Headphone amplifier

[Tekko]

Heres a variation of my amplifiers, a low power version meant to drive a pair of headphones:

http://i.imgur.com/mknb7.png

It does sound pretty good for beeing powered by a 2x14V 500mA wall wort and biased to around 20-25mA per channel.

[lineup]

You have high gain for being a headphone amplifier.
39k/1.5k = x26
You should not have higher than 4-10 for gain

[nightanole]

Agreed, my last amp was a gain of 2x with a 1.4vrms input and 64 ohm cans, and it was very loud at 12 o clock.

I always wondered why people have headphone amps with +-12v-15v rails. You cant send more then +-5v into a set of cans even at 600ohm.

[Tekko]

Some headphones are hard to drive and needs large voltage swings or high power up to over a watt to give any satisfying volume, my headphones dont produce any usable volume at full volume when connecting to my mp3 players, at the computer line out u barely hear anything.

Why gain on my amp is so high is cuz its actually the driver stage for a bigger amp, it was just a test to see wut it'd sound like with headphones.

[nattawa]

Originally Posted by nightanole

Agreed, my last amp was a gain of 2x with a 1.4vrms input and 64 ohm cans, and it was very loud at 12 o clock.

I always wondered why people have headphone amps with +-12v-15v rails. You cant send more then +-5v into a set of cans even at 600ohm.

I use 600-ohm AKG 240DF driven with Benchmark DAC-1 USB (+/-15V headphone amp?) every day and didn't feel they get incredibly loud. Signal of 5V peak over 600-ohm load would pump out 21mW(rms) power. Since most phones are rated at 1mW for its SPL, and if we think about a speaker system rated at 1W 1m for a comparable SPL, 21W power into that speaker really isn't much either. Many of us here have amps of way more than 100w/ch, so I guess +/-15V power rail for 600-ohm phone is not insane.

[nattawa]

Originally Posted by nightanole

Agreed, my last amp was a gain of 2x with a 1.4vrms input and 64 ohm cans, and it was very loud at 12 o clock.

I always wondered why people have headphone amps with +-12v-15v rails. You cant send more then +-5v into a set of cans even at 600ohm.

I use 600-ohm AKG 240DF driven with Benchmark DAC-1 USB (+/-15V headphone amp?) every day and didn't feel they get incredibly loud. Signal of 5V peak over 600-ohm load would pump out 21mW(rms) power. Since most phones are rated at 1mW for its SPL, and if we think about a speaker system rated at 1W 1m for a comparable SPL, 21W power into that speaker really isn't much either. Many of us here have amps of way more than 100w/ch, so I guess +/-15V power rail for 600-ohm phone is not insane.

[Tekko]

No need for double posting.

[nattawa]

Originally Posted by Tekko

No need for double posting.

Sorry, but I never did post twice 15 minutes apart. Something must have gone wrong somewhere. I wish there was a way for me to get rid of one of them. You comment indicating double-posting could be out of someone's NEEDS is interesting.