[manbear]

It's hard to say exactly without knowing the specs for your receiver's headphone jack. I would think anything in the 250-300 ohm range would be pretty safe. My point was just that you shouldn't assume 600 ohms is too much-- 600 ohms could easily work fine as well. That said, your receiver will certainly be able to power 50 ohm headphones like the Senns in terms of volume. The potential problem is that if your receiver has a high output impedance, as many do, then it will affect the frequency response of the headphones, possibly making the bass sound boomier. This might be subtle or you might even like it. I wouldn't worry about it too much. 

 

[moican]

Thanks again manbear! Reading the onkyo's manual, it sais something about 200mv/470 ohms at the rec out, output. Nothing about the headphones output. So it will probably cause deterioration to the low frequensy with such cans.

 

[manbear]

  So it will probably cause deterioration to the low frequensy with such cans.

Potentially. Something like a bass boost type of sound, nothing really terrible though. 

 

[billybob_jcv]

The rec out is a completely different situation - not the same as the headphone port at all.

 

[rubinstein]

have you considered buying budget dac/amp such as E10 or E7k in case of using laptop. If you are using desktop, consider buying Asus xonar dgx pci soundcard.

 

[manbear]

IMO, you should start with the headphones. Just get the ones you want, and try them with your receiver. If you're happy with the sound, forget about impedance and enjoy the music. If you're not happy, then it's time to think about headphone amps. 

 

[moican]

Thank you all guys.

 

[moican]

Hi everyone! I had asked onkyo for the amps headphone out specs and they came back with these figures:
 
Impedance 2.5 mV/47 kΩ (PHONO MM)
Phono Overload 70 mV (MM 1 kHz, 0.5%)
 
Do they look decent?
How should I use them? What impedance type cans should I look for? It's not an option a headphone amp for me. Not now at least, so please don't suggest me buying one.
Thank you.

 

[manbear]

  Hi everyone! I had asked onkyo for the amps headphone out specs and they came back with these figures:
 
Impedance 2.5 mV/47 kΩ (PHONO MM)
Phono Overload 70 mV (MM 1 kHz, 0.5%)
 
Do they look decent?
How should I use them? What impedance type cans should I look for? It's not an option a headphone amp for me. Not now at least, so please don't suggest me buying one.
Thank you.

Those are specs for the phono section (turntable input). Something must have been miscommunicated, because that has nothing to do with the headphone amp. 

The headphone amp on receivers often has high output impedance, so just get some high impedance headphones. Like 250-600 ohms. But don't sweat it too much. 

 

[kraken2109]

I've used 18ohm headphones with my Denon. I think there is a slight bass boost, but only by a few dB. Obviously different receivers will be different but just try headphones and see.