DIY: Amplifier selector box

After a full recap of the Sansui 661 receiver, It would be nice to compare it to my also fully recapped Marantz 2016 receiver using the same set of speakers. Unfortunately, swapping wires is not as easy as it sounds if you have to deal with pulling gear from the entertainment center and messing with tons of wires. After you are done, you completely forgot how does the first piece sounds like. So I have decided to build a simple amplifier switcher. It is not a new idea and basically, it is a sort of reversed speaker switch box.The main piece in this switch box is a 4PDT heavy duty switch with on-off-on positions. You definitely do want on-off-on so there is no chance that two receivers will be connected to the same set of speakers even for a split second. Who knows what’s going to happen.

So the list of parts is:

1. Small aluminum or plastic box (choose plastic if your speaker binding posts are not insulated)
2. 6 pairs of speaker binding posts (total of 6 red and 6 black)
3. 4PDT on-off-on switch
4. Speaker wire

The idea here is to have speaker outs from receiver connected to the switch box and from there wires goes to one set of speakers. All controlled by the 4PDT switch. Here are the pictures of the build. If there are any requests, I will post a wiring schematic but it is pretty self explanatory. The middle binding posts go to the speakers and left/right posts go to receivers.

Aluminum box with holes drilled:

Speaker binding posts and 4PDT switch:

Parts installed in the box:

All wired:

Complete switch box:

14 thoughts on “DIY: Amplifier selector box

  1. Matt Reply

    I’m trying to make one of these, and I’m really nervous about the wiring…. A schematic would be awesome… Actually, a picture of the bottom of the switch with each pole labeled would be incredible. Possible labels:



  2. Pingback: Building a Receiver/Amp Selector Switch

  3. Alex Reply

    I’m looking at building this exact box. I like the enclosure you used, but can’t seem to find it anywhere. Could you post where you got it?

  4. Gurkan G. Reply

    Thanks I did this with exactly the same materials as your. still can be found on eBay as of today. my additions for newbies..

    While drilling back panel for banana terminals use 7 or 8 mm driller, if you use 8 mm you will have around 1 mm gap which will allow you to adjust the terminals so that they get exactly in line.

    Also for the back take measure after you put the cover/lid ON.
    For the front take the measure without the cover lid and position the center.

    Diagram will be like this. Matching Numbers will form the bind between switch and terminals.
    check photo and below figure and you will see it for yourself if you need proof.
    I verified this from an elect. engineer as well.

    front/ Switch
    on 4 3 2 1
    off 8 7 6 5
    on 12 11 10 9

    top line / reds 10 9 6 5 2 1
    bottom line / blacks 12 11 8 7 4 3

    If you have the chance I suggest you paint the box with metallic black paint.

    soldering is not easy let someone else do this for you, or use terminal clips alternatively.

    for cable use your existing cable that you already use for your ht or hifi.

  5. Max Reply

    When i want, to put one amp on this, to switch between two pairs of speaker, how would the diagram look like? I would be very happy if anybody could tell me.

  6. Lars Reply

    Here is how you should connect this switch.
    A = Amplifier
    SP = SPeaker

    A1 L+ A1 L- A1 R- A1 R+
    SP L+ SP L- SP R- SP R+
    A2 L+ A2 L- A2 R- A2 R+

    • Alex Post authorReply

      ON-OFF-ON switch prevents having both speakers to be on at the same time (even for the split second). Just a bit of protection. ON-ON is fine but I would recommend turning the amp off before switching the speakers.

      • Lukky Reply

        OK, thanks, safer is better then. Thanks again for the reply and the great article.

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