h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

OK. new set of very old speakers. very massive very old, hand built speakers, built to an origional Tannoy design, possibly from the 1940s, or perhaps a bit later.
they're huge. and have some passive controls on the front, for the trebble.

The confusion is, rather than standard binding posts on the rear, they've a wird 'socket'.... that I'm not sure what it is!

its a three pin socket, rahter like a plug layout (triangle with two at the bottom spaced apart, and then a third, larger hole above, at the point of the triangle).

Distance between the holes is 20 MM.

the two bottom holes are smaller, and the single larger hole at the top, is, well, larger.

the two bottom holes seem to be a common 'polarity', and the single, larger hole at the top, is the oppsoite polarity (I tested with the cable from teh HiFi, just sticking the bare speaker cable into the holes).

I think one of the bottom holes goes just to the drive, and the other to the tweeter.

not sure if the unit has a seperate tweeter, or if its the tannoy concentric driver/tweeter thing

the three holes/socket, doesn't have the 'bit' around it, for the outside 'sleeve'? of an XLR so I can't just test if one of my XLR mic cables fits... - wondering if its some kind of three pin nutrik (never actually seen one of those so not sure), or... something else entirely... - I'd prefer to get an actual 'plug' to wire onto the end of the speaker cable, rather than just hanging wires ain and resorting to paperclips and matchsticks to hold stuff in the holes etc... (guess I mgiht be able to remove the back pannel and solder direct inside but, again not hot on doing that if I can avoid it) - problem is the person who origionally built them died, about five years ago, and I've not idea what the name or model of the design is to research it online etc, and as they're handbuilt, they don't realy have the seriel/model number on them, etc...

Could you try just plugging stuff into them until something works?

Traveller in Time digging in a box with spare connectors
"Your discription reminds me at best of an antenna connector on a tube radio. The massive build seems to be a verry big speakerbox.

Read there is no power cord as passive treble suggests.

'the bottom holes goes just to the drive, and the other to the tweeter'
This route is not realy clear to me.
The drive and tweeter suggest there are

As far as I know most common speaker boxes contain a two pole connector
a pair of wires goes in his case to the control on the front (a filter)
the filter splits into one pair for high one pair for low

Hmm, not happy with the passive control, this would either be a carbon film based variable resistor (very low power) or a wire resistor with tap (would act as a coil {low resistance} for low frquencies) "

I'm sure I've seen such connections many years ago, 2Legs, but I can't find anything on the web about them.

I don't have any wildly exotic enough connectors to just plug until I find the right one!; its not banna plugs, its not jack, or its cousins, its not XLR, its not RCA/interconnects.... or any others I've got laying about - not entirely sure what nutrik are, that might be a posibility (never seen or used them as far as I know), I've researched as much as I can on the limited information I have and I'm hedging towards their being bulgin connectors... yeh, I'd never heard of them either - may end up buying a bakerlight set of them, to try 9wll may as well get origionals ) fakling all else, I've a nice expensive set of mounted on recessed plates, ordinary binding posts able to take either bare wire or banana clips/plugs, so may mount them on the back, and just wire to whatever wiring is currently on the odd terminals - think the plate is about right size to go into existing plate hole on rear of cabinates Oh, and their not DIN as far as I know (not like any DIN I've seen anyhow, or used; though weve got DIN on the rear of the 1940s radiogram now in the front room if we want to try find suitable expansion speaker to hook up to that) Once I've got the speakers working, I can have a look at getting that radiogram working then the virticle turntable

Any chance of a link to a photo posted on something like flickr? Do you have a multi-meter (Can be bought for a tenner) to check for continuity and resistance?

PP.

See here. sounds like an old 5 amp rounf 3 pin socket used in the 40's to 60's https://upload.wikimedia.org/wikipedia/commons/f/ff/BS-546-3-pin-plugs.jpg

Working link:
http://upload.wikimedia.org/wikipedia/commons/f/ff/BS-546-3-pin-plugs.jpg

I remember plugs like that from ye 60s!

You could get yourself to the nearest British Legion, there's bound to be some ex services people who would know exactly what you've got there and how to connect it up.

I have a friend who has recently moved into a brand new house in the UK and this type of socket fitted in some places. I believe that they are designed to work a lighting circuit for stand alone lamps.

PP.

http://www.diy.com/departments/mk-2a-1-gang-white-unswitched-socket/262173_BQ.prd

PP.

OO... will have a loook at them... remember this is only carring the audio signal, so its not got any real voltage etc or current on them, even if it does look somewhat like a mains three pin plug arrangement of the three holes on the panel on the rear of the speaker shall check those links