How does processor loop work?

Ah, so the processor loop really is for the external parametric equalizer. Not processor in "pre/pro", but a sound processor. And processor loop can't be used to provide HT integration. That was a source of confusion, as I've seen mentions to processor loop when people asked for two channel and HT integration. Thanks for clearing it up.

Basically it is a "pass thru" with no volume (controlled on pre/pro) nor tonal influence.

Theo, if you connect the pass through output to the pre/pro, how will you connect the rest of the system? The power amp has one set of input, and can't connect both the preamp and pre/pro to it at the same time.

Ah, so the processor loop really is for the external parametric equalizer. Not processor in "pre/pro", but a sound processor. And processor loop can't be used to provide HT integration. That was a source of confusion, as I've seen mentions to processor loop when people asked for two channel and HT integration. Thanks for clearing it up.

Theo, if you connect the pass through output to the pre/pro, how will you connect the rest of the system? The power amp has one set of input, and can't connect both the preamp and pre/pro to it at the same time.

Yes, it's easy for all of this to be confusing, because the terminology tends to be used loosely and inconsistently. But properly speaking a processor loop and a home theater unity gain bypass are two completely different things.

A processor loop, as I indicated, allows an equalizer or any other external signal processing device to be inserted into the signal path of a 2-channel system. It is located ahead of the volume control in the preamp or integrated amp.

A home theater bypass allows the home theater system to utilize the 2-channel main speakers as part of its overall speaker system, by feeding its two front-main line-level outputs into the home theater bypass/unity gain INPUTS of the 2-channel preamp. When home theater bypass is selected on the 2-channel preamp, the volume control (and all other controls) on the 2-channel preamp are bypassed, so that the home theater unit's volume control (and only that volume control) will control the volume of all speakers.

Hope that clarifies things a little more.

Regards,
-- Al

Not sure if your question was answered so here goes:
Take front L&R output of pre/pro connect to input labeled
PROC, Unity Gain or HT pass thru. Then take 2 channel pre out put to amp. It's that simple and I just discovered this about a year ago. Actually the Ayre rep turned me onto it at RMAF but I wanted to try tubes and went with Audio researcg LS26. It is agreat soulution that cost the price of the 2 chennel preamp and one set of cables.