Receiver driving 600 ohm phones?

Stereo receiver, 70 watts at 8 ohms.

Could I hook this up to drive 600 ohm headphones?

That's about a watt into 600, so you could do it, but be very careful with both the phones and your ears.

This assumes the amp has common ground: both black terminals shorted to each other. Standard headphone connector is common ground. A few receivers use bridged outputs: the black terminals are live, NOT grounded. These can be harder to adapt to TRS headphone work.

For 600Ω-only use: Put 470Ω resistors between the amp output and the headphone jack. That not only drops max power to 1/4 watt, when you pinch and short the headphone cable the amp does not feel any pain at all. (True, most amps survive shorts, but why try when you can easily protect?)

For any-headphone use: wire 100Ω and 47Ω in series. 100Ω to the red post, 47Ω to the black post. Take the headphone output from the junction, return to the black post. This gives aboyt 7 volts behind 30 ohms, which "can be shown" to be near maximum power for most headphones. If you like to live loud and dangerously, flip the resistors: now you have 14V behind 30 ohms, which may be needed for some 600Ω phones, but is over a Watt into 32 ohms.

Thank you gentlemen.

Speaker switch box:

http://www.avahifi.com/root/audio_basics/ab_pdf/ab1993-07.pdf

I tried out PRR's suggestion and it worked great, though I could still use a little more volume before the amp clips.

You could drive the headphones directly but maybe with some overvoltage protection. You will gain 4-5 dB, not much but some. I think the best you could do is to change to 150 or 32 ohms cans, still 20 Vrms into 600 ohms, pretty loud?

Good to see you here peranders

If you are here can you sugest an absolutely top, money no object audiophile (transparent, not euphonic) headphone amp? I ask because i think you have lots of experience in the audiophile domain and I'm interested in something (transistor,tube,mosfet I don't care) that will work stellar and will not care if the phone has 30 or 600 ohm. I know it is not an easy task, but maybe you know a project like that.
Thanks.

chrissugar

Thanks for the kind words but noone of the audiophiles regard my stuff as especially audiophilic... too boring.

Please take a look at my stuff and see if you think it is "audiophilic" enough :grin:

Marshall-style stereo jack mounted in a plastic Grayhill switch tube. 470 resistors across the tip and ring terminals. Common ground taken from right speaker output.

Thank you peranders but SMD scares me. :grin:

chrissugar

Nothing to be scared of unless they aren't smaller than those I use.

Are the speakers being used at the same tiime as the phones? Probably not, my guess.
So you need to address what to do with all the power not being used by the speakers. Solid state does not mind much, and that is what you are using. But put a scope on the phones output just in case to make sure you are not creating any gremlins by not havind a load on the power amp.