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2 amps 1 pair speakers

terrys999

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guys.
i want to switch between 2 amps to 1 pair of speakers safely.
a simple a b switch,
something that doesnt degrade the signal.
any ideas???
 

nils.kdc

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I did that by using two basic ab switches for domestic lighting I had available at my house , after checking with a voltmeter that in the switching from a to b I had a point of total cutoff with infinite resistance. I don't know if this is fully without risk and should be recommended, but it worked very well.

I did it to ab compare some reputably good but very different amps i had at home at some time (plinius sa103 class a, mc intosh 2200, ear 509, crown k1) and it truly was an eye opener for me.

The differences were so negligible to me I lost about all interest in amps per se. I had read it a thousand times, but it really sunk in then : it's all in the speakers, and in the room
 

MaxwellsEq

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In electronic parlance, you need a "break before make" switch.
 

diablo

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fpitas

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Elgrosso

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Hi guys, reviving this thread since it’s precisely my need. I’ve found many other answers in other threads and elsewhere but it’s still unclear.
Like the OP I want to compare few amps I have around, and some of them have tubes (I understood they should always have a speaker load).

What is unclear is: do I need a switch for the amp input and a switch for the amp output?
Meaning switching RCA signal between both amps, and in the same time switching speaker signal from both amps, to the same speakers.
All the boxes I've found are doing only one thing at a time.

For ex RCA box:
selecteur-de-source-rca-4-vers-1-reversible.jpg


Or speaker box:
selecteur-audio-1-vers-2-reversible-pour-enceintes-amplificateur-noir-s.jpg


Is it ok to only use the speaker box, feeding both amps with a simple Y all the time? Even for the tube amps?
The thing that makes it harder is that I also have to switch dsp settings between both, as it’s active and I will compare only a specific bandpass that I would have corrected upfront to match.
Right now it takes me few minutes to swap: power all amps OFF/unplugging/replugging rca & bananas/dsp change/all ON, with some care to not mess up.
Best would be something that does all, with a remote, but I’ll use what I find.
 

diablo

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Elgrosso

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Thx diablo, I suppose I could use this one with some kind of load on the second speaker out for the tube amp when not in use.
Still need a way to switch rca though.
Too bad I sold my spare SHD as I could have used it to split 2 into 4 channels and switch.

This one is what I need, but $1400, more than the amps :D
ABX-front-top_1_copy_a586f958-611e-4a92-b38d-231424e35f84_1024x1024.jpg


That’s something we could share here, buy one for all and share as it’s not something we need forever.
 

diablo

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Thx diablo, I suppose I could use this one with some kind of load on the second speaker out for the tube amp when not in use.
Still need a way to switch rca though.
Too bad I sold my spare SHD as I could have used it to split 2 into 4 channels and switch.

This one is what I need, but $1400, more than the amps :D
ABX-front-top_1_copy_a586f958-611e-4a92-b38d-231424e35f84_1024x1024.jpg


That’s something we could share here, buy one for all and share as it’s not something we need forever.
I'm pretty sure you could use the Y-splitter you mentioned earlier. Assuming that the amps have a fairly high input impedance.
 

Zek

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What is unclear is: do I need a switch for the amp input and a switch for the amp output?
It depends on what you actually want to connect, whether it's just two amplifiers to one pair of speakers or at the same time one audio source to two amplifiers.
There are several solutions for connecting one source to two amplifiers depending on the type of amplifiers themselves.
 

Elgrosso

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It depends on what you actually want to connect, whether it's just two amplifiers to one pair of speakers or at the same time one audio source to two amplifiers.
There are several solutions for connecting one source to two amplifiers depending on the type of amplifiers themselves.
The main goal is to compare two (or more) amps for midranges duties on the same active speakers, just a step closer to a real ABX one day.
The switch being as quick as possible.

But:
- one amp is a diy tube amp (not by me) I don't know its input impedance
- both amps would be driven by 2 channels of a minidsp flex8
- this dsp will also have to switch between presets, dedicated to each amp (mostly for levels, with limited EQ)

If both amps can be fed with a simple Y then I could use one of these A/B boxes, maybe find one with a remote.
Switching both the speaker box and the dsp should take few seconds with then 2 remotes, not perfect but much better than the 1 minute as now.
But it’s still unclear how to safely present a load to the tube amp in both A/B cases.
 

somebodyelse

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A switcher for tube amps came up in one of the other threads possibly on ABX. IIRC it included dummy load resistors that were connected to the amp before the speaker was disconnected. Don't remember whether the timing was handled with logic or mechanics, but it does add a load of complication.There's also the matter of making sure you can't hear a difference in the switching process if the goal is to ABX.
Edit: https://www.audiosciencereview.com/...ca-xlr-amplifier-switch-box.11157/post-328189
 
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