Quality of headphone amp in AV receivers

[Ongii]

Hello!
What is the quality of the headphone amp/output of standard AV receivers?
(I'd like to keep the minimum amount of devices, if this doesn't affect performance).
Thanks!

 

[Blorg]

It depends on the device, but it's often an afterthought and very bad. A common issue is very high output impedance which will change the tonality of many headphones. My understanding, this can happen if the headphone output it derived from the main speaker output just with attenuation. High output impedance can also mean very low current into low impedance headphones like most planars, which also tend to be insensitive and need a lot of power.

You can often get better performance from a dongle than a receiver. But it does depend on the specific device and how they designed the headphone output.

 

[oleg87]

They are almost invariably implemented by tapping the speaker amps through a resistor, which makes them quite load-sensitive (I've seen anywhere from 100ohms to 400ohm output resistors, so the effect will vary). For high-impedance headphones, this will likely be benign (older headphone designs were probably intended for such usage). For low-impedance headphones, you may get pretty large frequency response shifts, and you will lose a lot of power to the resistor (though since it's running off a speaker amp, it will likely still be adequate).

 

[Ongii]

OK... thanks.
I'll look for a dedicated headphone amp, to insert in the chain between the source (HDMI) and the AVR (that I keep, for listening multichannel with loudspeakers).
At the moment I have found only an Essence device.
An alternative would be to use a digital output from the AVR, but mine doesn't have such :-(

 

[pukemon]

If you still check out this thread I had an onkyo 3009 I couldn't test the headphone output because some relay kept tripping not allowing much sound to get through. I then upgraded to a Marantz 7702mk2 after awhile. I enjoyed the headphone output on this prepro and iirc it used an Asahi Kasei 4493? and the sound was just as smooth as the sound from my speakers. I ended up buying my first portable DAC amp, the JDS Labs CD5, because I was not going to use a heavy pigtail or sit in front of my TV to listen to headphones. so YMMV. If it's a newer receiver it may be using class D amps and I don't know how the home theater market is going since I left the US.