Switching a single set of speakers between two amps


I search all of the posts first, and found one discussion about this topic, 4 years ago, but it wasn't exactly the same as my situation, so I am going to bring it up to see if anyone has experience with this.

Right now, I am using my AV system in conjunction with my analog system - I have a Garrard 301/Jelco 750L/Zu Audio 103, feeding a Tavish Adagio, which then rolls into an NAD T187/Classe CA5300, connected to KEF speakers (stereo pair are the LS50s, which might be the biggest bargain in audio -I used to run Maggies - the 3.7i's, which are great speakers but turn out to be wrong for my room - contact me if you want to buy them! - I initially purchased them for a different environment, where they worked great, but they are too large for the room I am in now).

What I want to do - continue to use the NAD/Classe system for A/V and also for surround SACD, but install an integrated tube amp - maybe the Line Magnetics 518- for use with vinyl and tape.  I located one well-reviewed switch - the Beresford TC-7220 - and I wanted to see if anyone has actual experience running two different amps with the same speakers, especially when one of them is a tubed amp.
tgr

I used Niles SPK-1 and SAS-1
When the AVR power up, the 12V trigger output from the AVR triggered the SPK-1 switch AVR output to Main speakers, the SAS-1 line level switch the sub-woofer input to AVR, and the speaker level switch connect a 25ohm100W resistor to each of the tube amp output channels.
I can't tell a difference between Luxman in the way and without but then I'm not a strong believer in cables so I don't see how a well executed relay system like Luxman (basically same design as their integrated amps) would contribute or subtract anything from the sound. Copper is copper.
I have also looked for a simple convenient solution to this question. At present I have my speakers operated either by my hifi front end (all tube) or by an AV system with AV preamp and solid state power amp.

Not too onerous to switch as both power amps sit between the speakers and I use banana plug speaker wire ends, so it is just a plug and unplug operation (keeping in mind almarg's caution about the tube power amp being turned off).

Wonder how transparent the Luxman unit is?
Luxman AS50. Look for them on eBay. They will switch up to 3 pairs of speakers, or 3 amp into one set. I've got one of these puppies in my home theater room to switch between my 5 channel amp, 2 channel SS and 2 channel tube amp. It comes with remote.

Another option, manual is MapleTree Audio Design. They will build you a custom switch. I have a 2 into 1 switch built by them that I'd be willing part with if interested.

https://hollowstate.netfirms.com
I have a similar situation, main speakers being vintage custom built Tannoy HPD 315's. To power the HT part of my system, I built Class D Audio amps w/larger power supplies, and two amp modules, for 500 Wpc. They actually  sound so good, they get used 90-95% of the time.

I have, along with a Primare pre-pro, a separate preamp I built from a kit (Transcendent Sounds Grounded Grid) with a few key upgrades in parts, that does everything I need it to do, and very well at that.

So, I run my tubed phono stage into the Grounded Grid, and then into my SET 300B amp, for an all tube system. I use two identical sets of Tempo Electric Big Twist 12 gauge solid-core silver speaker cables, so all I have to do is change cables at the speaker end.

By the way, I also get to use a Garrard 401 TT, Dynavector 501 arm, and Zu Audio 103R cartridge. For me, it's the best of all worlds. Anyway, that's my work-around for a similar scenario.

Regards,
Dan
The thing to be careful about, as you may realize, is that most tube amps should not be operated unloaded, at least when they are processing a signal. So you would have to be sure that the tube amp is always turned off when the other amp is being used. Or, alternatively, have the switch constructed or modified such that it connects suitably chosen resistors to the outputs of the tube amp when (and only when) the other amp is selected.

Regards,
-- Al

tgr,

I have no personal experience, but dealers do it all the time with switch-boxes that allow different combinations of amps/speakers.

Good luck!