rewiring preamp will it work

James is correct, aside perhaps from the last sentence, but I and I suspect most of the others have been assuming that the second RCA output would go to the input of a headphone amplifier (as I mentioned), rather than to headphones directly.

A preamp having a nominal output impedance of 560 ohms will be unable to directly drive nearly all conventionally designed headphones, with any semblance of good results.

As far as connection to the amp output is concerned, without knowing the specs of the components that would be involved I suspect that you would be putting way too much signal into the phones unless the volume control is set extremely close to the bottom of its range.

Regards,
-- Al

Very informative reply Al, greatly appreciated. When I plug in the input impedances of my amp and and headphone amp to the equation I get 13.5k ohms for the combined input impedance. So its definitely more than 10x the listed 560 ohm output impedance of the preamp, but not if in fact sometimes increase to 2-3k as you mentioned. What do you think?

just heard back from Cary:

"Hey Ron,
Since the output of the AES-3 is buffered with a follower, I see no reason why it wouldn't work. You certainly couldn't drive a pair of headphones from that output, but it would work into the input of a headphone amp"

Sounds like a plan! Given the 24x ratio, and the info Mingles provided that there is no output coupling capacitor, and the response from Cary, I think you'll be fine.

Concerning splitters, opinions tend to be divided. FWIW my own opinion is that it is very likely that using an external splitter would be sonically indistinguishable from modifying the preamp to do the split internally. So I think that Viridian's suggestion is a good one. Here are some additional splitter alternatives, from Audioquest (the second and third of the three items shown).

If for any unforeseen reason you find that having both signal paths connected at once compromises the sound quality of either, HifiHarv's suggestion of a switchbox would be a reasonable fallback approach, IMO. The DB Systems DBP-2JAU/5 would be a good choice, IME/IMO. See the nearby links labelled "photo" and "review" for more information on it. You would connect it in "reverse," with the preamp going to the jacks labelled "Output," and the two amps going to two pairs of "Input" jacks. But again, I don't think that a switchbox will be necessary.

Regards,
-- Al

Does anyone know anything about high quality balanced splitters, particularly solid ones?