Preamplifier sound Quality impact in home theatre bypass

I’m wondering if insertion of a pre-amplifier between the AV processor and the amplifiers negatively impacts sound of home theatre. It has no impact on stereo listening since source of stereo sources are connected directly to the pre-amplifier and don't involve the AV processor.

This is done as part of my Home theatre bypass configuration and it works really well but I’m wondering if I’m diminishing openness of what I’m listening to.

I initially did this because I wanted the tube pre-amplifier to influence sound since I had a solid state amplifier. However now I have a tube amplifier and the benefits of the tube pre-amplifier may not be as much of an impact. However taking pre-amplifier out of the chain is not ideal.


Listen with and without in your HT listening and decide for yourself with your equipment vs relying on someone else's personal result

I have been doing it for years, and haven’t had anything call attention to it. I watch a few concert videos in 5.1 and find the music to sound just as good as when I played the same discs on my old Ayer C5xe that played DVD. 

I consider HT a step or 2 below 2 channel and wouldn't worry about a pass thru on your preamp,  all that should be in the signal path is some wire and a selector switch.  Assuming you chose a preamp with good switches, it shouldn't affect HT.

A better solution, that I use, is to have an amp built with 2 inputs so HT pre-out goes directly to the amp.


I have a Mc class D bypassing into Mc AB and definitely have not experienced any sound degradation at all.  Granted I have good cabling throughout my entire gear + on the sub.   

It depends on the tube pre and the path the signal is taking for HT Bypass. 

In many of the designs I've seen, the HT Bypass is the equivalent of putting an RCA female to female adapter between two RCA pairs. Wouldn't bother me unless you noticed a change running with and without. 

McIntosh Integrated Amps and Preamps have a really slick pass through.  I set my Dad's MA8950 with an Anthem MRX 540 and it is seamless integration 

The MRX's trigger out goes to Mac's control trigger input and when you turn the MRX on it puts the Mac in Pass-through.  It's just using the MA8950 amps,  with the MRX doing volume and powering the centers and rears. 



I have a Rogue preamp I use with HT bypass. The AVR plugs into specific HT bypass RCA ports, which are only activated with the Rogue OFF. Therefore no effect on tubes, and unless the HT relay switch is defective, no impact on sound. A simple pass through. 

I’m going to have to agree with carlsbad2 on this one. I have a Parasound pre amp with theater bi-pass and never looked at it the same way as my 2 channel audio system.  Only a bi-pass for convenience…Everyone’s ears hear what they hear 

Never really noticed a difference. Used to use it with moon, now use it with a Sudgen preamp. I would need to test it out, but the Sugden is on standby when HT bypass in in use. 

if there’s tubes involved it probably goes through the tube circuits on the preamp even when it’s in bypass.