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Preamps w/HT BYPASS that works when preamp is OFF.

I have spent quite a bit of time researching this issue here and on other fora. I have been looking for a thread that lists the stereo preamplifiers that have home theater (or "cinema," as some manufacturers call it) bypass that works while the preamp is turned off. I think this list would be very helpful to those who have hybrid systems, which seems to be the majority of audiophiles.

I will start the list with those that I know operate this way, either through personal use or through research on the internet. Please feel free to add to the list, but please limit your contributions to the preamps that meet the criteria above. I will break down the list into two parts: Preamps that have XLR HT bypass input and preamps that have RCA HT bypass input only. Please indicate next to the model listed whether it is tube or solid state, fully-balanced or not.

PREAMPS WITH XLR HT BYPASS INPUTS:
Cary SLP-05 (tube, fully-balanced)
Cary SLP-2002 (tube, fully-balanced)
Modwright LS 36.5 (tube, fully-balanced)

PREAMPS WITH RCA HT BYPASS INPUTS:
Supratek Chenin (tube)
Supratek Chardonnay (tube)
Rogue Perseus (tube)
Gill Audio Alana (tube) [HT Bypass available by request]
Aesthetix Janus (tube, fully balanced)
Aesthetix Calypso (tube, fully balanced)

If you know through personal experience that any of this information is incorrect, please feel free to suggest corrections.
asindc
asindc OP
32 posts
 
CORRECTION:

PREAMPS WITH RCA HT BYPASS INPUTS:
Modwright LS 36.5 (tube, fully-balanced)

I had previously listed this in the XLR category. Its HT bypass is single-ended only.
kennyt
1,226 posts
 
What good is it unless the unit defaults to the HT bypass when off? Otherwise you'd have to turn it on, switch to HT by[pass, then turn it off right??

I ask as I am currently looking to add a solid two channel preamp to my HT and use an HT bypass, but can't see how the 'when off' part is important, and also can't see how tube gear does it unless it is just a straight wire across the in to output....
audiofankj
373 posts
 
The Dodd Battery Powered Preamp HT bypass works when the unit is off.
asindc OP
32 posts
 
Kennyt:

I know that the Carys' HT bypass works when the unit is powered off. They default to HT bypass automatically. I cannot speak for the others on this list.

The benefits of "powered off" HT bypass:

1) Saves on tube life if it is a tube pre. Not a big difference, but a difference nonetheless.

2) Saves on electricity. Same idea as #1.

3) Saves on heat. Same idea as #1 and #2.

4) Prevents possible ground loop hum from being introduced into HT system by having it interact with the preamp while it is on. I have experienced this before.

5) The security of knowing that the preamp is not processing the HT signal at all. Some might prefer that, but I do not.
asindc OP
32 posts
 
ADDITION:

PREAMPS WITH RCA HT BYPASS INPUTS:
Dodd Battery Powered Preamp
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