Bryston 2WSB switch box to choose amp that drives speakers


I really want to be able to choose between a low power amp for tv/background music and my good amp for serious music sessions. I'm tired of amp rolling, have posted recently about this and got good advice not to use two sets of speakers cables but only one live amp. So I'm thinking of a device like the Bryston, but have the speaker outputs be the amp inputs and the amp input be the speaker output. As long as only one speaker is selected at a time...electrically that should work. My only concern looking at the schematics is that the red positive leads are wired together and the black negative leads are switched. Could this still cause voltage to be applied to the unpowered amp? If so would swapping polarity work? There's a schematic on this page. 
https://reverb.com/item/10151350-bryston-2-way-speaker-switch-box-model-2wsb-sc1
Any help on this would be greatly appreciated.
treynolds155

Showing 5 responses by treynolds155

Al I really appreciate your looking into to this to that degree! This is really quite maddening that there isn't a quality switch that can accommodate it. I mean really I'm just looking for a four pole double throw switch that won't muck up the sound. I'll end up making something if I have to.


LOL I could use more exercise but I switch back and forth so often that it's a real pain in the arse, to the point where often I don't even bother connecting the good amp. The reason I do this is because the good amp runs in class a, so it's very hot and draws a lot of electricity, plus its a vintage Threshold that I want to limit its use for music only. I can't justify watching the news or football with it in the audio circuit. I could just use the tv's speakers for that but I also like the little amp for background music, I'll leave it on all day while coming an going. I won't do that with the Threshold. 
Thanks again Al for really digging in there to help out!! I think there's two versions of Bryston's switch so that may be the difference between common + or - rails. Regardless...probably not safe either way. I looked at Nile's site and their DPS-1 specifically states two amps switched to one pair of speakers but nothing specific about both +/- being switched and it sounds like their binding posts are anemic so probably not the quality I'm looking for.  

I'm starting to think a custom one is the way to go. I found this four pole/double throw on/off/on switch:
https://www.grainger.com/product/HONEYWELL-Toggle-Switch-24D454

All I'd need is a project box and some Cardas binding posts and wire. As long as the switch wasn't noisy it should work great. Thoughts?

Thanks 
Tim
That's a great price Al. I like that it has an off position in the middle, no way for the two amps to be mixed. This whole thing may seem crazy to some but I'm really looking forward to being able to just flick a switch for what amp I want to use. 

I'll post pics when this is built, I've updated my system pics for my recent updates. Pales in comparison to a lot of the systems here but she's mine and it does sound real good...especially when the Threshold is in play. 

Thanks for all the links and help guys!!
Tim