ARC LS 25 Mk 11 Bypass

Simply put, it is a theater throughpass and the volume is controlled by your pre-pro. There is no sonic improvement. What you are doing is using your processor's left and right front channel outs into the processor (bypass) left and right inputs on your stereo preamp. From there you are running your left and right main outs into your amp. I just don't get why all you guys are so confused

“Absolute nonsense ...it is a pass through and no degradation of the signal.”

Maybe you are the One who is confused. When you say it’s a pass through, are you implying it just passively switches wires because that is not the case. The preamp is accepting the analog signal just like it would from any other source and then setting its volume level at unity gain, so as not to change the output level of the incoming signal.

Does your home theater bypass work when your REF3 is turned off? I don’t think so, and I know it does not work with the LS25MK2 turned off (we are talking about the LS25MK2 here aren’t we). If the 2ch preamp has to be turned on, then it is NOT just passively switching wires, it is actively doing "something", and I am telling you for a fact, that with the LS25MK2 in home theater bypass mode, it does change the sound from your ht processor and not in a positive way. I would assume the REF3 would be on the same level as a VTL7.5, and the change in sound through those units would be (is) extremely minimal, but this is not the case with the LS25MK2. The lowering in sound quality (degrading) was easily noticeable.

I respectfully disagree.

"I am telling you for a fact, that with the LS25MK2 in home theater bypass mode, it does change the sound from your ht processor and not in a positive way."

What I don't understand is how you make that comment inasmuch as you need to use the throughpass mode to accept the L + R main channels from your pre-pro to be used for HT.

Now if you tell me that you are using the preamp part of your processor for 2 channel music I would suggest that any good 2 channel preamp will always sound better than a HT pre-pro.

For you to suggest that the sound is degraded by your ARC preamp suggests that you have to have used only your HT pre-pro for music listening without using the thoughpass input (IOW, your L +R main outs from your pr-pro go directly to your amps). I have done this with my system and I still disagree with you. There is just no degradation of signal when used through the "processor" input on my Ref 3

This whole discussion hints at a feature I have wanted from tube preamp manufacturers out there: implement HT pass-through WITHOUT the need for the tube unit to be powered on. Why is this so difficult? If all we want is to route a pair of inputs directly to the outputs, can't this be done through the use of one toggle switch? And in the other position, which perhaps is an open circuit, the preamp works in a normal way when powered on.

As for all the back-and-forth posts above, no matter how the Ref3 may differ from the LS25 sonically in "normal" mode, I gotta believe that they would NOT differ in HT pass-through if none of their active stages are in line for this mode. I suspect ARC's implementation (switches, wires and connectors) with HT pass-through is consistent from model to model. With that said however, it escapes me how insertion of any component (with its input and output connections and the additional IC) can result in NO kind of signal degradtion vs. the pre/pro's front channel outputs directly to the amp. In a high-resolution system, just that one extra pair of ICs can do far more damage than any inserted "pass-through" component. This may be a miniscule difference, and for the sake of HT usage, who cares, but I suspect there would certainly be a noticable change in dynamic contrasts even with the most linear ICs out there.