Headphone Amp Selection?

dfuhr7gm

Member
2012-02-11 11:43 am
Hello Guys,

i am owning a pair of AKG K271 Headphones. Their ratings are 55Ohm and 200mW Pmax, and i want to drive them to the top - talking about voltage. That would make 3,3V - how can I achieve that? I would really be glad if you could tell me about an easy and cheap-to-build amp :)

Thanks in advance!
Daniel
 
Hi Daniel,
The 3.3V requirement refers to the RMS voltage (for a sine wave, which is customary for audio). You'll actually need 4.7V peak and around 100mA peak.

What to recommend depends on whether you want wall power or batteries, and whether you want a PCB or willing to do your own layout. But here are a few options:

O2 - NwAvGuy: O2 Details
M3 - The M³ Stereo Headphone Amplifier
SDS - SDS Labs Headphone Amplifier | HeadWize
Eaton - Build This High Quality Headphone Amplifier | HeadWize (Gain is very high. I'd suggest changing R5 to 4.7k; and deleting R6 to lighten the load on the opamp; then bootstrapping R7... so many options).
 

dfuhr7gm

Member
2012-02-11 11:43 am
Wow, thank you for your answer!

I am thinking of a desktop system, probably powered by an old laptop PSU (19V 2,1A)

PCB is no problem for me, I want to design it by myself and got plenty of manufacturing options in school.

Well, I think I will go for the third option, by SDS Labs.

Again, thank you very much for your help!
Daniel