Is unity gain a real HT bypass?


I'm looking at maybe purchasing an older preamp that has a unity gain setting that is meant for connecting an external processor. Does anyone know if this is a true ht bypass that avoids the preamp's processing circuitry, or will running the ht signal through this path noticeably affect the sound? The unit in question is a bat vk5i, though I'm also curious about this question in general. Thanks. -Dave
dbw1
If the BAT degrades the sound of hometheater, you wouldn't want to use it for two channel either?....correct?

Dave
I would guess that Unity Gain is techically different than Bypass. IMHO, bypass would suggest a direct, alternate path from input to output, whereas Unity Gain is the normal path with zero attenuation/amplification of the source signal. This arrangement allows the downstream main power amp to "see" the same signal that the upstream processor will be sending to the other amp(s) for the remaining channels.

So while it's technically different, the outcome is practically the same. As Dave suggests, if the BAT is capable (transparent, resolving, etc) of producing high quality two channel, then it should be satisfactory in a home theater signal chain.

For disclosure purposes, I have a BAT VK-3i running my dedicated two-channel rig (BAT power, Magneplanars).
In general if the preamp isn't transparent, then its unity gain setting won't be either.

Does anyone know if this is a true ht bypass that avoids the preamp's processing circuitry

I'm not aware of any "processing" going on in 2-channel preamps so I don't think this should be a concern.
That all sounds reasonable. If anyone has tried this specifically, I'd like to know the results. BTW, what do you all think of this particular equipment match - the bat vk5i with theta front end and amp, snell c/v speakers. Current preamp is a simaudio p5. Thanks. -Dave
I would guess that Unity Gain is techically different than Bypass. IMHO, bypass would suggest a direct, alternate path from input to output, whereas Unity Gain is the normal path with zero attenuation/amplification of the source signal.

I'm pretty sure that in both cases, unity gain and HT Bypass, the attenuator is bypassed -- that's the alternate path. All you're trying to accomplish is having volume control happen at the multichannel preamp. You'd still want the HT input and output of the preamp to be buffered not simply electrically connected. Unless some HT Bypass implementations provide gain, I think the two terms are equivalent.
If the preamp is a tube preamp does the bypass mode bypass the tubes and unity gain run the signal through the tubes?
My understanding is that Unity gain, HT Bypass, Cinema Pass Thru, Processor Pass Thru are all different names for the same thing. Each manufacture has come up with a name to make it appear as they have a special input/output circuit. But from my research I have done they all pass thru without coloration and that you still use the volume on your pre/pro and that the unitity gain just allows you to hook up to the amp without Y adapters and the confusion that would present. I am saving to buy the ARC LS26 to place between my MX135 and MC352. Taking donations if any one wants to help?
Hi Dave,

I agree with Theo that they are all similar. The tube preamp is setting the volume at the point where no gain should be added to the signal. The only way you would have a true bypass is if the Preamp would not need to be turned on and the signal would still be able to pass thru it. The only tube preamp I know of that operates this way is the Cary 2002.

Setting the preamp @ unity gain should improve the sound, otherwise there is no since in having it.

I am using a theta carmen II, theta dreadnaught, meridian 568.2 and aesthetic calypso in my home theater system. I would be happy to answer questions about the set up if you pm me.

Doug