[Cymbal Monkey]

Could I just wire multiple headphone outs in parallel? Do they have to be impedance matched? Anyone know what they're doing more than being good with an iron and metre like myself?

 

[ShinyFalcon]

You can parallel headphones, and they don't have to be impedance matched. It would obviously help if they were matched though.

 

[JamesL]

Bump, I'm also very interested in a good, practical method for implementing multiple-outputs on a headphone amp.
 
If me and a buddy wants to hit up the xbox360 in the middle of the night, I really don't need perfect sound quality, as long as I can achieve decent spl-matching between different headphones.  

 

[amb]

Yes, you can connect multiple pairs of headphones in parallel.  Use identical headphones if you can.  If not, at least headphones of similar impedance and sensitivity.  This is so that one won't be louder than the other.

 

[Cymbal Monkey]

My mate and I don't have identical headphones, sadly, would there be a way to adjust one but not the other if the difference is too great?

 

[nikongod]

You can match them with resistive attenuators, like the shure volume control. SQ may suffer depending on how your particular headphones respond to high source impedances.
 
You could also just build him a Cmoy or something.

 

[amb]

Quote:

My mate and I don't have identical headphones, sadly, would there be a way to adjust one but not the other if the difference is too great?

Best way is to use separate amps, one per headphone, so you have independent volume controls.
 

 

[Mad Max]

LOL
 
Build two M^3? =P

 

[Cymbal Monkey]

If only I had that kind of money.