Strange 2 pin plug socket in upstairs master bedroom (Victorian end Terrace house)

[Valvepower]

Fingers crossed…

Leak is a massive rabbit hole on the net, so Just a couple pointers it’s the speaker plugs/sockets used on the Leak Transistor amplifiers Stereo 30 and Stereo 70.

As for manufacturers it could be someone like Bulgin, Clix, Cinch or McMurdo – something to get started with.

You will encounter the more common round and flat two pin Bulgin plug and sockets, as used on early valve Leak equipment, but that won’t be your kiddie.

Terry

[G6Tanuki]

Curiouser and curiouser.

I also remember something very similar being used on the old Ever Ready AD35/B126 type batteries, and also as the loudspeaker connection on some 1960s car radios.

[Bittyboy]

Originally Posted by Valvepower

Fingers crossed…

Leak is a massive rabbit hole on the net, so Just a couple pointers it’s the speaker plugs/sockets used on the Leak Transistor amplifiers Stereo 30 and Stereo 70.

As for manufacturers it could be someone like Bulgin, Clix, Cinch or McMurdo – something to get started with.

You will encounter the more common round and flat two pin Bulgin plug, and sockets as used on early valve Leak equipment, but that won’t be your kiddie.

Terry

Thanks Terry,

I've googled this and its very interesting what comes up... The pins look about the right size but that 12mm distance apart is a problem as from my Minicraft drill plug, the distance between the pins is around 9mm. (See attached photos).

I'm sure it is for a low voltage gadget of some sort... if not audio (I think it is !)... could it have been for a handheld trouser press or some low voltage lamp or weather station ??

Best Regards, Joseph.

[Hartley118]

Originally Posted by Valvepower

This speaker and radio got removed from the kitchen when my grandparents got their first transistor radio a Dansette Dorchester in the early 1960's.

Terry.

Interesting how the advent of the readily portable transistor radio in the 1960s superseded the need for the extension speaker and its associated wiring which used to be integral to so many houses - and schools too.

Martin

[G6Tanuki]

A quick trawl through the Mullard Magic website shows a few possibilities...

https://mullard.org/collections/comp...ket-plug-combo

https://mullard.org/collections/comp...tch-13mm-pitch

https://mullard.org/collections/comp...tapping-points

https://mullard.org/collections/comp...tapping-points

[Bittyboy]

Originally Posted by G6Tanuki

A quick trawl through the Mullard Magic website shows a few possibilities...

https://mullard.org/collections/comp...ket-plug-combo

https://mullard.org/collections/comp...tch-13mm-pitch

https://mullard.org/collections/comp...tapping-points

https://mullard.org/collections/comp...tapping-points

Thanks for the links G6

The 9mm pitch plug in the last link looks like the correct plug for this stange grey plastic plug socket that was in the master bedroom of my newly bought house.

It definitely looks like a loudspeaker plug socket of some sort, the fact that it was grey plastic and not Bakelite dates it to the 1950's era and beyond as that was when the first modern plastics appeared.

I keep on thinking that it could have been wired to a intercom handset phone in the downstairs hallway or kitchen but I can't seem to find any trace of any old wiring to back up this theory but if it was many years ago and lots of decorating has taken place then it is possible someone did a good job removing the old wiring and filling and painting where the wiring once was !

I still keep on wondering why on the right hand side of the fireplace skirting board ?... could it have been for a low voltage fan/blower that plugged into it to blow more air into a coal fire for more heat ??

I still think "mantle piece clock" !... but all the ones I've seen seem to be proper mains voltage and this plug socket screams LOW VOLTS !

Wonder what else it could have been for ?... The electric arm chair scenario I came up with a few posts back seemed to tally well with where that plug socket was placed, the only thing wrong was I think that the motors in that arm chair would draw more amps then the capacity of that little socket could handle... so that is why I don't think it was for an electric reclining arm chair !

Maybe a reading light of some sort from the 1960's/70's seems possible

[Bittyboy]

Originally Posted by Hartley118

Interesting how the advent of the readily portable transistor radio in the 1960s superseded the need for the extension speaker and its associated wiring which used to be integral to so many houses - and schools too.

Martin

My mum had a Dansette Dorchester back in the early 1980's that she was given by a relative and I remember that round tuning scale on the right hand side when looking at the radio from the front... by 1985 it got super seeded for a PHILLIPS 08534 radio boombox from Argos with detachable speakers ! which we still have somewhere !

[Hartley118]

Originally Posted by G6Tanuki

The 9mm pitch plug in the last link looks like the correct plug for this strange grey plastic plug socket that was in the master bedroom of my newly bought house.

It definitely looks like a loudspeaker plug socket of some sort, the fact that it was grey plastic and not Bakelite dates it to the 1950's era and beyond as that was when the first modern plastics appeared.......

I still keep on wondering why on the right hand side of the fireplace skirting board ?...

Terminating the underfloor wiring at the side of the fireplace suggests that it was connecting to an item placed on the mantelpiece. Yes, it might have been neater to locate it like a clock plug just above the mantelpiece, but so much easier to screw the socket to the skirting board and run the underfloor wire directly to it without chasing out any plaster.

Martin

[Bittyboy]

Originally Posted by Hartley118

Terminating the underfloor wiring at the side of the fireplace suggests that it was connecting to an item placed on the mantelpiece. Yes, it might have been neater to locate it like a clock plug just above the mantelpiece, but so much easier to screw the socket to the skirting board and run the underfloor wire directly to it without chasing out any plaster.

Martin

Good point Martin,

I would agree with that, and just to add that I think that socket may have been connected to a low voltage power supply DC transformer module that could have been (or still is !) located under the floorboards in that area of the room and connected to the wiring of the old MK BS1363 230v power sockets via a rose ! ... I also think those 1363 MK mains sockets are much older then this strange 2 pin socket...

I would say that it was an additional low power socket professionally installed by a professional tradesman or a confident DIY'er who knew what they were doing - Whatever the reason for that plug socket, It must have been for a very good reason of importance to someone for someone get all the floorboard up in that area and make such a neat job before it was removed and deleted by the decorator last month !

I'm going to draw a sketch of this setup tonight and post back here then quoting this post...

Best Regards Joseph

[startreksteve]

Looks like a sewing machine plug from the 60's, I used to PAT test a few of them at work.

[Bittyboy]

Originally Posted by startreksteve

Looks like a sewing machine plug from the 60's, I used to PAT test a few of them at work.

Thanks for your post Steve,

I was thinking this morning in one of my earlier posts it could have been for a sewing machine of some sort ! - I can just imagine some nice old lady sitting down in her chair back in the swinging 1960's comfortably sewing garments from sewing patterns she bought down at Abakhan fabrics or Woolworths !

Her sewing machine might have been on a small high table situated in that right hand alcove !... If it wasn't a sewing machine that strange 2 pin plug socket was used for... She may have just had a normal sewing machine that plugged into one of the points of that 1363 MK socket but her husband may have rigged up a low voltage light for her ? (like the ones in in an operating theatre) so she could see what she was doing when sewing the patterns !

I could be wrong ! and it could have been for some nice old boy who had his Emco Unimat SL hobby lathe set up on a table in that alcove and also needed a low voltage work light when he was turning down o gauge steam locomotive parts for his model making hobby ! you never know !

Whatever that socket was for I guess we'll work it out sooner than later.

Best Wishes, Joseph

[Bittyboy]

Originally Posted by Bittyboy

Good point Martin,

I would agree with that, and just to add that I think that socket may have been connected to a low voltage power supply DC transformer module that could have been (or still is !) located under the floorboards in that area of the room and connected to the wiring of the old MK BS1363 230v power sockets via a rose ! ... I also think those 1363 MK mains sockets are much older then this strange 2 pin socket...

I would say that it was an additional low power socket professionally installed by a professional tradesman or a confident DIY'er who knew what they were doing - Whatever the reason for that plug socket, It must have been for a very good reason of importance to someone for someone get all the floorboard up in that area and make such a neat job before it was removed and deleted by the decorator last month !

I'm going to draw a sketch of this setup tonight and post back here then quoting this post...

Best Regards Joseph

As promised just quoting my previous post with the sketches I promised I'd make of the setup, If had that have been a low voltage DC socket for a mantle piece clock power supply... see attached sketches.

It could have well been wired to a low voltage bell transformer putting out 8 volts AC at 500ma - That is possible if it was used for a small light or clock...

EDIT:

I just remembered I had bid on and won an old 8v bell socket late last year with a similar set up to my sketch and a 2 pin socket !... only that socket looks much more older than the grey modern plastic phantom plug socket with unequal size pins holes that this topic is about and what it was for ! - The brown Bakelite socket mounted on the bell transformer board is bigger and has both pin holes the same size - See last couple of images after my sketches.

[Graham G3ZVT]

Originally Posted by Hartley118

Interesting how the advent of the readily portable transistor radio in the 1960s superseded the need for the extension speaker and its associated wiring which used to be integral to so many houses - and schools too.

Martin

Indeed. There was such a speaker above the kitchen door in my childhood home, it's one of my earliest memories. It had a toggle switch mounted on the baffle board. I have no memory of the speaker being used though.
My grandfather owned a garment factory, and I can well imagine it was for Music While You Work, but surplus to requirements.

An equally early memory was the kitchen radio, which I remember well enough to be able to identify it now as Pye 47X.

The speaker was connected via a twisted cloth covered flex that led out of the kitchen, it could only have gone to the radiogram in the dining room. So, was the radio a later acquisition which made the speaker redundant, or was it kept in use to listen to gramophone records in the kitchen? (78RPM only from that RG). Like the socket under investigation here, I guess we will never know!

[duncanlowe]

If the socket is the size of the connector on your Minicraft, it's very low current. So nothing with much power draw.

Sewing machines such as the one my Mum had in the 60s were mains powered with built in mains powered work lamps.

Sorry but I don't buy a remotely mounted transformer / low voltage power supply. It just wasn't a thing until wall warts came along (or when I used my train transformer to power a battery lamp).

[Bittyboy]

Originally Posted by rambo1152

Indeed. There was such a speaker above the kitchen door in my childhood home, it's one of my earliest memories. It had a toggle switch mounted on the baffle board. I have no memory of the speaker being used though.
My grandfather owned a garment factory, and I can well imagine it was for Music While You Work, but surplus to requirements.

An equally early memory was the kitchen radio, which I remember well enough to be able to identify it now as Pye 47X.

The speaker was connected via a twisted cloth covered flex that led out of the kitchen, it could only have gone to the radiogram in the dining room. So, was the radio a later acquisition which made the speaker redundant, or was it kept in use to listen to gramophone records in the kitchen? (78RPM only from that RG). Like the socket under investigation here, I guess we will never know!

Very cool story Graham.. It could have well been for an external speaker located in that master bedroom for music coming from the sitting room HiFi in the room downstairs - I can just imagine Jimmy Mack by Martha and the Vandellas being played through that speaker in 1967 or Boogie Nights by Heatwave being played during 1977 !

It definitely seems like an old audio socket for an external speaker...

[Bittyboy]

Originally Posted by duncanlowe

If the socket is the size of the connector on your Minicraft, it's very low current. So nothing with much power draw.

Sewing machines such as the one my Mum had in the 60s were mains powered with built in mains powered work lamps.

Sorry but I don't buy a remotely mounted transformer / low voltage power supply. It just wasn't a thing until wall warts came along (or when I used my train transformer to power a battery lamp).

Thanks for your post Duncan

I have a gut feeling that some of the other posters are right when they say it could be for an external speaker of some sort.

I find it hard to believe either that someone could go to all the trouble to rip up all the floorboards just to fit an concealed low voltage power supply, what if something went wrong with it or worse it caused a fire ?... I would have thought for safety reasons the power source to that socket would have been placed somewhere sensible so that it's easy to get to should something go wrong ?

More likely that the wire (speaker or bell type wire) did pass through the floor and into the room below which is the main lounge sitting room - No sign of such a hole in the ceiling downstairs now as its probably been filled and painted over and over again... but in the room upstairs I did lift the carpet whilst that socket was still in place and saw a off white speaker or bell like wire going into a hole that's drilled in the floorboard and right up to the skirting board...

My vote is for external speaker socket unless someone has another socket the same that's still in use today ! and could put us out of our misery lol !

Best wishes, Joseph.

[Hartley118]

Well, the mystery socket would have fulfilled the prime requirement for an extension speaker socket, which is to be totally incompatible with any mains sockets in the building.

Martin

[Valvepower]

Hello,

A few things.

I had a look through the Leak Blurb, instructions and manuals and couldn’t find any mention of the manufacturer or type of the plugs used on the Stereo 30 and 70. I’ll keep my eyes peeled whilst at jumbles, rallies, and swapmeets for one of these sockets.

I did note the Stereo 70 has a set of remote speaker sockets; so, the ‘extension’ speaker idea carried on – in a few products – into the days of ‘separates’ hi-fi equipment.

Well, the mystery socket would have fulfilled the prime requirement for an extension speaker socket, which is to be totally incompatible with any mains sockets in the building.

Regards speaker sockets, there is the outlawing of 4mm banana or test plugs on the speaker connections on [modern] audio amplifiers manufactured in the last 30 years or thereabouts. This came in with EN 60065 (could also be in IEC-65 – I can’t remember?) safety/LVD requirements. This requirement may have it's roots in Europe as from memory this came about as some chap in Denmark plugged a set of speaker leads with 4mm plugs into the European Schuko power socket and electrocuted himself – this could well be folklore, but it was a requirement of the standard, thus generating the Neutrik SpeakON plugs and sockets and the blanking of 4mm holes on [wired] speaker terminals. One common practice is to firmly fit plastic blanking plugs into the 4mm hole on the speaker socket [if it has a 4mm hole] – if the end user removes the blanking plugs and uses a 4mm plug, its up to them, but the unit passes compliance tests and leaves the factory with them fitted, so the unit is compliant. You must use tool like a screwdriver to remove them, as they are quite firmly fitted in place.

This part of the standard revolves around the insertion of a test pin/pointer/probe - from memory of 4mm diameter - into an piece of equipment and it becoming live or hazardous in use.

I think the plan was to outlaw the use 4mm plugs and sockets on speaker leads thus removing the potential hazard (?) of speaker leads fitted with 4mm plugs.

Mind you, you could take a piece of speaker lead and bare the ends and sick them in Schuko power socket!

I can just imagine Jimmy Mack by Martha and the Vandellas being played through that speaker in 1967

Ah, Jimmy Mack by Martha and the Vandellas. Crikey, Motown… now there another rabbit hole with the engineering, musicianship and song writing of Motown, the other rabbit holes are Atlantic and Stax. If your into Motown checkout Motown Memories show with Steve Weaver on Caroline Flashback.

Terry

[FrankB]

Have you checked it for any voltages? I would test for AC first.
If your home had a "maids room" there may be a similar outlet there for a bell or chime.
It -is- possible it was some type of antenna outlet also.
I would check the attic to see if a wire runs directly from the plug to the attic also, and if so, you may be able to follow it. Just some thoughts.

[Roger Ramjet]

There is only one way to answer this Enigma ... The carpet has to be rolled back, the floor boards have to come up then the cable has to be traced back to the other end (which may involve lifting floorboards in other rooms).

Rog