'80s Polytone Making Combo into Head with external jack

[Ric Lee]

So I bought a Polytone Baby Brute/Baby Taurus though it is really more like a Mini Brute I as it is a 12 inch speaker with no reverb but that's the naming designation of the time.

I got it for a steal and everything works great electronically but the speaker had a repaired hole with what appears to be superglue and tissue paper. It's smaller than two dimes. Sounds really good still but I briefly had a Polytone 103 that had electrical issues and one 15 inch speaker and two 8 inch speakers that wouldn't work but the 15 alone sounded great for fingerstyle and single note picking with really nice mid representation for solo playing and a really nice room presence.

So I bought a nice large closed back 15 inch cabinet that came preloaded with a huge WGS 15 speaker WGS BG15C 15" Bass or PA Speaker 8 ohm ( special) | | Reverb and I may replace it with a Polytone 15 speaker I have but going to try the WGS out first(I'm aware there's a lot of mojo with an original speaker and the ohm rating possibly).

Sorry for the preamble but my actual question is with my Polytone 12 inch combo. I want if possible to have the option of disconnecting the internal speaker with a speaker defeat switch and using the 15 inch cabinet only being driven by the head within the combo. I looked online with a normal google search but kept on getting results for Buckethead style guitar kill switches or just disconnecting the wires to the speaker and using a combo speaker as an extension cabinet which is not what I want to do. I know I've seen this before but having difficult finding it myself. I'm pretty handy with a soldering iron and power drill and have wired up my own pickups and pots and such.

I was originally going to do this with the Mega Brute I got in but I think that sounds perfect for it's application as is and is self contained, I know I saw someone post about doing that as well if they want to share their experience with that. Barring this application I'll just use the internal wires from the head inside the Polytone 12 inch combo and wire that to a guitar head speaker cable and run that out the back to the 15 inch speaker cabinet but would like the option of using the 12 or the 15 external with the combo.

Obligatory Polytone photo!

[rahsaan]

Could be wrong, but I think a lot of jack sockets can be wired so that inserting the plug breaks the internal connection. You'd probably want to plug/unplug it with the amp power off though.

[jazzmus]

Unless im missing the point... use a DPDT on/on switch, route the speaker cable from the power amp to the sw, one side straight back to the internal speaker, the other to a jack out to use with a external speaker.
i have the exact same amp, closed back, yours dont have a ext speaker and pre/main out already?

[Ric Lee]

Unless im missing the point... use a DPDT on/on switch, route the speaker cable from the power amp to the sw, one side straight back to the internal speaker, the other to a jack out to use with a external speaker.
i have the exact same amp, closed back, yours dont have a ext speaker and pre/main out already?

Ah yeah I think I’ll look into the DPDT switch as you advised. I’ve never done anything like that any links you are aware of if not I’ll look it up!

It has an extension speaker jack and a preamp out but I just want to run the 15 extension with the head and not the internal speaker at the same time as when I’ve used the ext cab ext jack before the internal speaker still runs.

The preamp out could work but I’d need to run that into another power amp to power the 15 cabinet as that would be just a preamp signal out from my understanding.

[jazzmus]

No link sry, its just how id do it.
dpdt on/on
from power amp -
Positive to terminal 3, negative to terminal 4.
Speaker in the amp, positive to terminal 5, negative to terminal 6.
Then from switch - 1 is positive, 2 is negative, wire to the ring and tip of the Jack after checking the wiring (pos/neg) on your speaker cab.
this Will make the amp as is with the switch up and ext speaker with the toggle Down. If you look at a dpdt switch function it Will make sense ( i Think, perhaps, haha).

[Ric Lee]

No link sry, its just how id do it.
dpdt on/on
from power amp -
Positive to terminal 3, negative to terminal 4.
Speaker in the amp, positive to terminal 5, negative to terminal 6.
Then from switch - 1 is positive, 2 is negative, wire to the ring and tip of the Jack after checking the wiring (pos/neg) on your speaker cab.
this Will make the amp as is with the switch up and ext speaker with the toggle Down. If you look at a dpdt switch function it Will make sense ( i Think, perhaps, haha).

That explanation was helpful I’ll look that up as well!

[jazzmus]

[Ric Lee]

Thanks!

[sgosnell]

If you just want to disable the speaker, a simple on-off switch will do that. Cut one of the speaker wires, put the switch between the ends, and done. With the switch off, the circuit is broken and the speaker won't work. On, and the circuit is made, and the speaker is on.