Changing speaker outputs on a valve amp - UK Vintage Radio Repair and Restoration Discussion Forum

dazaaa1 · 4th Mar 2012, 10:00 pm

I've got my hands on a lovely working Akai 1070W amplifier removed from a tape deck. It is working fine with headphones but the speaker terminals are 1/4 jacks and all my hifi speakers have normal bare wire terminals. So how do I go about replacing the jacks with normal screw terminals? Placing them isn't a problem, but the wiring is. Currently each jack has 4 wires, 3 on seperate terminals and a 4th connected to one of the 3 terminals. The schematic is rather confusing and doesn't seem to show any of these (Unless I am reading it wrong) Surely there will be one wire to the +ve terminal and one to the -ve?

Would really appreciate some help. Can get pics up if needed.

Thanks

teetoon · 5th Mar 2012, 2:25 am

Hi, I don't know this model but suspect it had internal speakers? This would explain the 4 wires to the jack sockets. They will be switched to disconnect the internal speakers when a plug is inserted into the socket.
Are there 2 wires from each socket that are currently not connected to anything? These would have gone to the speakers. The wire that connects to the terminal with another wire will be common or -, the other wire +. Pics would be useful so we can be sure but I'm almost certain that's what you've got there.
If this is the case then connect your speakers to those 2 wires.
Hope this helps.
David.

dazaaa1 · 5th Mar 2012, 10:10 am

I think you've pretty much got it there. I didn't notice that there was a switch above the terminals which switched off the internal speakers when you wanted external speakers. This (from memory) leaves me with 3 wires that come from somewere else and the rest are all linked to the switch. Since someones already hacked this out of the tape deck and cut quite a few wires, would I just be able to remove all the wires to the switch and connect the remaining 3 wires to the new speaker terminals? I will get some pics up asap.

Daz

Diabolical Artificer · 5th Mar 2012, 10:17 am

Or it could be you have two secondaries connected in parallel from the OPT.Take some readings with a meter. You could solder a 1/4 jack to your speaker wires,an easy job to do.A

4th Mar 2012, 10:00 pm	#1
dazaaa1 Retired Dormant Member Join Date: Jul 2009 Location: East London, UK. Posts: 43	Changing speaker outputs on a valve amp I've got my hands on a lovely working Akai 1070W amplifier removed from a tape deck. It is working fine with headphones but the speaker terminals are 1/4 jacks and all my hifi speakers have normal bare wire terminals. So how do I go about replacing the jacks with normal screw terminals? Placing them isn't a problem, but the wiring is. Currently each jack has 4 wires, 3 on seperate terminals and a 4th connected to one of the 3 terminals. The schematic is rather confusing and doesn't seem to show any of these (Unless I am reading it wrong) Surely there will be one wire to the +ve terminal and one to the -ve? Would really appreciate some help. Can get pics up if needed. Thanks

5th Mar 2012, 2:25 am	#2
teetoon Heptode Join Date: Dec 2010 Location: Barnstaple, N.Devon, UK. Posts: 557	Re: Changing speaker outputs on a valve amp Hi, I don't know this model but suspect it had internal speakers? This would explain the 4 wires to the jack sockets. They will be switched to disconnect the internal speakers when a plug is inserted into the socket. Are there 2 wires from each socket that are currently not connected to anything? These would have gone to the speakers. The wire that connects to the terminal with another wire will be common or -, the other wire +. Pics would be useful so we can be sure but I'm almost certain that's what you've got there. If this is the case then connect your speakers to those 2 wires. Hope this helps. David.

5th Mar 2012, 10:10 am	#3
dazaaa1 Retired Dormant Member Join Date: Jul 2009 Location: East London, UK. Posts: 43	Re: Changing speaker outputs on a valve amp I think you've pretty much got it there. I didn't notice that there was a switch above the terminals which switched off the internal speakers when you wanted external speakers. This (from memory) leaves me with 3 wires that come from somewere else and the rest are all linked to the switch. Since someones already hacked this out of the tape deck and cut quite a few wires, would I just be able to remove all the wires to the switch and connect the remaining 3 wires to the new speaker terminals? I will get some pics up asap. Daz

5th Mar 2012, 10:17 am	#4
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,663	Re: Changing speaker outputs on a valve amp Or it could be you have two secondaries connected in parallel from the OPT.Take some readings with a meter. You could solder a 1/4 jack to your speaker wires,an easy job to do.A __________________ Curiosity hasn't killed this cat...so far.