Question about my AKG K702s and my 80s receiver

[Caw Caw]

Hello! I wanted to ask a clarification about the receiver that I'm using, a Pioneer SA-540. My question is, could it be able to drive my AKG K702s (62 ohms, 91 dB/mW), or is it better for me to stick to a dedicated amp?
I attached an image taken from the receiver's manual where the output voltage is shown. I don't understand that schematic very much and I'll be very glad if someone could clear that out for me. Thanks in advance, and sorry if I'm coming out as too demanding!

 

[GREQ]

It looks like the schematic is explaining that using an 8 ohm load with an output of of 67 millivolts, it will generate a "single-pole" power of 1 watt (which could be what the "SP" is referring to).
If I'm correct (which I have no idea if I am) I don't think this is very powerful at all. Probably not enough for an K702 to be powered properly, especially considering it's quite inefficient.

If you have to crank up the volume on the amp quite high with these headphones, then it's definitely not doing them justice.

 

[ProtegeManiac]

Hello! I wanted to ask a clarification about the receiver that I'm using, a Pioneer SA-540. My question is, could it be able to drive my AKG K702s (62 ohms, 91 dB/mW), or is it better for me to stick to a dedicated amp?
I attached an image taken from the receiver's manual where the output voltage is shown. I don't understand that schematic very much and I'll be very glad if someone could clear that out for me. Thanks in advance, and sorry if I'm coming out as too demanding!

In addition to GREQ's post, that 1W will likely drop as the impedance increases, so not really. On top of which many speaker equipment have high output impedance, and even better headphone driver circuits with a lot of power tend to have a problem as these older equipment were also from back when headphones had to have a high impedance design to increase sensitivity and damping factor (ie even with high output impedance, if the load is also higher impedance, it takes less of a hit), so the output impedance is usually still too high. If you have both the damping factor issue can be more audible with lower power and current.

 

[Caw Caw]

Thank you guys a lot! It looks like it's better for me to buy a dedicated headphone amp It's a bit of a shame because I really wanted to use this amp, as it is a gift from grandpa. But I still have the option to use it with loudspeakers, if I'll ever become interested in them.

 

[GREQ]

I forgot to mention that vintage amps usually have very high power consumption, since they almost always send the entire speaker output to a huge resistor at the headphone out; so they're not a good for your electricity bill or the environment if you plan to only use it for headphones