Connecting one set of speakers to two amplifiers

gourav

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Hi friends. Recently I started having some problems with my AVR. It was at the service center for a quite a while, and when it came back, it again started giving issues. So I had to send it back to the service center.

In the mean time, I bought a used Fosi Amp so that I could at least use my bookshelf speakers. Now I'm going to get my AVR back and I'm wondering if I can keep both my AVR and Amp connected to the speaker. This way I'll have the option of not using my AVR for regular stuff like music listening, YouTube videos, etc.

Of course, I only want to use one amp at a time and will take care to ensure that both amplifiers cannot be switched on at the same time.

Here's my gear:
  • Pioneer VSX 534 AVR
  • Fosi Audio Bluetooth 4.2 Stereo Amplifier
  • Taga Harmony Azure B-40 bookshelf speakers
The speakers have two binding posts at the back like this:
1663734769783.png
So connecting the amplifiers won't be an issue, I can connect one to the top posts and another to the bottom posts.

So I want to know if there is any issue in connecting the amps like this. I am of course aware that switching on both at same time can create issues. But barring that I feel like this should be fine. Just wanted to check with the experts here.
 

spirovious

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So connecting the amplifiers won't be an issue, I can connect one to the top posts and another to the bottom posts.
With those jumpers and two amps, that will damage the amp which is not use.
What you need is use a passive or active speaker switcher.
 

Subbu68

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Those jumpers are for bi-amping. Upper set for medium and high freq and lower for the LF.

Rig up a switch or get one of the commercial one to switch the speaker to either of the two amps. Or run two sets of wires to the speakers and swap them. Mark them properly to identify which wire is connected to which amp.
 

Shammi Dang

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Hi friends. Recently I started having some problems with my AVR. It was at the service center for a quite a while, and when it came back, it again started giving issues. So I had to send it back to the service center.

In the mean time, I bought a used Fosi Amp so that I could at least use my bookshelf speakers. Now I'm going to get my AVR back and I'm wondering if I can keep both my AVR and Amp connected to the speaker. This way I'll have the option of not using my AVR for regular stuff like music listening, YouTube videos, etc.

Of course, I only want to use one amp at a time and will take care to ensure that both amplifiers cannot be switched on at the same time.

Here's my gear:
  • Pioneer VSX 534 AVR
  • Fosi Audio Bluetooth 4.2 Stereo Amplifier
  • Taga Harmony Azure B-40 bookshelf speakers
The speakers have two binding posts at the back like this:
View attachment 72072
So connecting the amplifiers won't be an issue, I can connect one to the top posts and another to the bottom posts.

So I want to know if there is any issue in connecting the amps like this. I am of course aware that switching on both at same time can create issues. But barring that I feel like this should be fine. Just wanted to check with the experts here.
With my own understanding I had connected two integrated amps to my speakers with two sets of binding posts at back. I use one amplifier at a time and by far it has not given me any problem. Logically we cannot use both amplifiers at same time with the connecting plates as damage might occur to speakers or amplifier. I am not sure as I am not a technical person but as a precaution and after reading this post I have disconnected one set of wires from back of speakers, simply detached the banana plugs. Hope you can use the speakers in the same way if you have banana plugs/spades attached to speaker wires, it will be easy to interchange wires when using a particular amp/av receiver.
 

mbhangui

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@spirovious is right. When two amps are connected to the same speaker, the amp that is playing has two loads connected in parallel
1. The speaker
2. The output circuitry of the non-playing amp which generally will be very low and will damage the amp that is playing. Even valve amps have an output transformer and the secondary winding act as a load

You can connect two amps to the same speaker by removing those strips on the back and connect one amp to the lower section (normally the low frequency driver) and connecting the other amp to the above binding post (normally the high frequency driver). This is called bi-amping.

I have also seen a vintage sansui speaker that had 6 binding posts in the back and they can be tri-amped.
 

Jayant_S

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Hi friends. Recently I started having some problems with my AVR. It was at the service center for a quite a while, and when it came back, it again started giving issues. So I had to send it back to the service center.

In the mean time, I bought a used Fosi Amp so that I could at least use my bookshelf speakers. Now I'm going to get my AVR back and I'm wondering if I can keep both my AVR and Amp connected to the speaker. This way I'll have the option of not using my AVR for regular stuff like music listening, YouTube videos, etc.

Of course, I only want to use one amp at a time and will take care to ensure that both amplifiers cannot be switched on at the same time.

Here's my gear:
  • Pioneer VSX 534 AVR
  • Fosi Audio Bluetooth 4.2 Stereo Amplifier
  • Taga Harmony Azure B-40 bookshelf speakers
The speakers have two binding posts at the back like this:
View attachment 72072
So connecting the amplifiers won't be an issue, I can connect one to the top posts and another to the bottom posts.

So I want to know if there is any issue in connecting the amps like this. I am of course aware that switching on both at same time can create issues. But barring that I feel like this should be fine. Just wanted to check with the experts here.
You need an analog switch to pick between the two amps feeding same speakers. Same thing has been discussed here :

https://www.hifivision.com/threads/my-three-months-journey-and-basic-set-up.78785/post-866603
 

gourav

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Thanks everyone. I guess it wasn't as easy as I had thought. Getting a switch is out of the question as the only ones I can find are no name ones and very expensive.

I guess I'll just get some banana plugs and physically change the amp when needed.
 

jsmithe

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Kannan

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The simplest solution is to use just one pair ofspeakers cables and switch them at the amplifier end.

If going for an amp switcher, do not use plain SPDT switches as that will add its own impedance and other issues.
The best switcher employs dedicated relays for each channel (can be both DC or AC).
 

arj

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Thanks everyone. I guess it wasn't as easy as I had thought. Getting a switch is out of the question as the only ones I can find are no name ones and very expensive.

I guess I'll just get some banana plugs and physically change the amp when needed.
exactly and + 1 to the below using bananas.
The simplest solution is to use just one pair ofspeakers cables and switch them at the amplifier end.
 

MaSh

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Thanks everyone. I guess it wasn't as easy as I had thought. Getting a switch is out of the question as the only ones I can find are no name ones and very expensive.

I guess I'll just get some banana plugs and physically change the amp when needed.
Does the receiver have pre out? Connect the pre out to the stereo amp' input 1. Fix a volume on the stereo amp. Connect speakers to stereo amp. When using receiver , set stereo amp to that volume. Volume control is at receiver. When using stereo amp switch inputs and adjust volume accordingly.


Do not connect both amps to the speakers unless you want an early Diwali.

MaSh;
 

gourav

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You can try DIY or get one made from a FM. See this thread https://www.hifivision.com/threads/diy-speaker-switch.69693/
Haven't had much success with DIY projects. Can try getting it done by some FM, will look up who all do this kind of thing.

Does the receiver have pre out? Connect the pre out to the stereo amp' input 1. Fix a volume on the stereo amp. Connect speakers to stereo amp. When using receiver , set stereo amp to that volume. Volume control is at receiver. When using stereo amp switch inputs and adjust volume accordingly.


Do not connect both amps to the speakers unless you want an early Diwali.

MaSh;
I want to keep the AVR off when using the stereo amp. So this solution won't work for me.

I'll probably just stick to switching banana plugs at speaker end as my AVR doesn't support banana plugs, so switching at amp end will be a huge hassle.
 

MaSh

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Haven't had much success with DIY projects. Can try getting it done by some FM, will look up who all do this kind of thing.


I want to keep the AVR off when using the stereo amp. So this solution won't work for me.

I'll probably just stick to switching banana plugs at speaker end as my AVR doesn't support banana plugs, so switching at amp end will be a huge hassle.
Hi,

You need to turn on the receiver only when you are using it. If using just the stereo amp, then the Input would be your other source and not the Receiver.

MaSh
 

gourav

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Hi,

You need to turn on the receiver only when you are using it. If using just the stereo amp, then the Input would be your other source and not the Receiver.

MaSh
Oh, I misunderstood earlier. Yes, that's actually a good idea. But my AVR doesn't have pre-outs. It has provision for a second set of speakers called zone B. Not sure if I can use that.
 
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