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ARC LS 25 Mk 11 Bypass

I'd like to get better "2 channel" performance out of my HT system (Bel Canto Evo 6 amp and PrePro processor, Theta CD transport). When I was at my local stereo store the salesperson recommended that I simply purchase the LS 25 Mk II. He told me that it has a "bypass" feature that will allow me to use the LS for 2 channel music and the PrePro for HT and multichannel applications...without having to move cords everytime I want to move between music and HT. I've tried to find literature on line that would explain how the wiring would work, but I've been unsuccessful. Has anyone out there done this with the LS 25 or some other preamp? If so, did you find the 2 channel sound to be substantially better than simply running it through the processor?
Thanks everyone.
riccap
tlg
69 posts
 
I have always wondered how this process works too. Does this mean that when your listening to HT through the 2 channel preamp the sound level on the 2 channel preamp can be set at zero or 100 and it doesn't matter because the HT is controlling the volume as long as the switch is flipped? Is their any sonic improvement from using a superior preamp and running the front left and right channels of the HT processor throught the 2 channel preamp or is this a mood point.
oneobgyn
410 posts
 
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
billbench
23 posts
 
“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.
oneobgyn
410 posts
 
I respectfully disagree.
oneobgyn
410 posts
 
"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
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