A switch for 3 amps

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you will want the SCC1 system configuration controller, I had one made for me custom, by Al Freundorfer  al@mapletreeaudio.com

I use it to control 2 tube amps, a CD player, and turntable hooked up to 2 different sets of speakers. I can switch from either amp to one of the sets of speakers, I can have both amps on and switch back and forth to the speakers to hear which amp sounds the best with what music I am currently listening to from either the TT or the CD player. it ran about $450.00 USD 2 years ago, just email Al and tell him how you want it configured and he wil quote you a price then build it for you.

I have an SET Class A Tube AMP and a Marantz SS amp connected to a Douk Audio "LITTLE BEAR". It can also drive two sets of speakers too so you have up to 4 amp/speaker combination. Key is the Little Bear presents a LOAD to the tube amp even if not selected. Some tube amps require that to be powered on. Been using it for two years with zero issues. Now, Amir at Audio Science Research poo poo’s this unit due to noise but I am thrilled with it.

The Luxman speaker selector switch mentioned above appears to drive 3 pairs of speakers on one amp ?  Not familiar with it and I can't any manuals to confirm it can handle 2 pairs of amps....  

@audiodidact I own and use the Luxman AS-55. It is solid and works well. Could be used for three different amps or one amp and three different pairs of speakers. Shop around for your best price.

@aricaudio 

Aric at Aric Audio built me one for just this reason. 

Luxman Amp and his 300 b amp.

He put a dummy load just in case I decided to switch bit for forgot to turn the tube amp off when switching. Tube amps needs load!

He built it keeping SQ in mind.

Maybe I'm missing something but I don't think the Luxman will work for what you are trying to do. It is simply a speaker selector with only one amplifier input. The Douk is also not the answer because it is designed to go between the amp and the speaker. You need something that has one source input for your preamp and two line level outputs to go to your amplifiers. Then you need an additional selector to direct the speaker level output from the one of the amplifiers to your speakers. The Douk could serve as the second selector but there is a better way.

+1 for Mapletree Audio. You specify exactly what you want and they build it to your needs. I have one and it is looks nice with a retro vibe, is built solidly, and is noiseless. As @alucard19 mentioned, Al Freundorfer is very helpful and he can build you a switch box that will do everything in one chassis. It isn't cheap but it's by far the most elegant solution. If you explain to him what you are trying to do he will custom build exactly what you need.

When you set this up you should use a consistent turn on/turn off procedure to protect your tube amps. With the amps off, set the switches for the amplifer and speaker output and then turn on the amp once everything is properly switched. As with all proper audio hygiene make sure your preamp is muted when you turn on your amplifiers.