7 Pin Din Wiring help... - UK Vintage Radio Repair and Restoration Discussion Forum

placemat · 2nd Mar 2018, 11:39 am

Hello!
I have a Revox PR99 MKII reel to reel that also has the Revox monitor speaker with it. It connects via the 7 pin din cable which is long enough if both items are set up in the rack, but I have since taken the PR 99 out of the rack and placed it upright with the monitor speaker on the shelf above. The seven pin audio cable now will not reach. I have looked everywhere to see if there are any seven pin din extension cables, but I've had no luck.
I can easily get seven pin din male and female plug ends, but I'm not sure what type of cable it is or how to wire them up correctly.
If anyone can help, I will be very grateful.
I've attached an image of the plug that I need to extend.

Ted Kendall · 2nd Mar 2018, 12:13 pm

Simplest way to do this is to slide back the cover and remove the shell from the existing plug - this will show you which, and how many, pins are being used. Then all you need is screened cable with enough cores, and away you go. You just need to wire the extender pin-for-pin, but make sure you connect the screen to the right pin - this is usually pin 2 which, confusingly, is the middle pin...!

placemat · 2nd Mar 2018, 2:02 pm

Many thanks Ted,

It's such a shame that I cannot find a male to female cable or even a female to female adapter. I have exactly this for a five pin din audio cable, but finding it for seven pin is near impossible!
Many thanks again for your help.
Steve.

Dave Moll · 2nd Mar 2018, 3:36 pm

Quote:

Originally Posted by Ted Kendall

pin 2 which, confusingly, is the middle pin...!

Presumably because the five-pin and seven-pin connectors are extensions from the three-pin one where the pins are labelled in sequence with 1 and 3 either side of 2 - then 4 and 5 inserted between and finally 6 and 7 added on the ends. That way the pins common to more than one plug retain the same numbers.

'LIVEWIRE?' · 2nd Mar 2018, 5:57 pm

This may be irrelevant, but Blaupunkt at one time used 7 & 8 pin DIN connectors with their car stereos and amplifiers. In those a multicore cable with an overall outer screen was used. No doubt necessary in a vehicle, an overall screen may not be essential for domestic use. A complication is that there are or were, two types of 7-pin DIN connector - in one the pins are arranged in a kind of 'horseshoe' shape, whilst the other has them in the shape of a Circle.

dseymo1 · 2nd Mar 2018, 6:11 pm

You'll also need a steady hand and good eyesight - horrible things to wire

emeritus · 2nd Mar 2018, 6:11 pm

The 7 pin DIN with all pins on a circle is sometimes found on Philips cassette recorders, but only a 5 pin plug is needed: the two extra pins are generally connected directly to the record/playback head and are presumably only used during manufacture for adjustment.

I have never come across a 7 pin extension lead or any back-to-back adapters, but Maplin always used to stock the plugs.

TonyDuell · 2nd Mar 2018, 6:49 pm

Quote:

Originally Posted by 'LIVEWIRE?'

A complication is that there are or were, two types of 7-pin DIN connector - in one the pins are arranged in a kind of 'horseshoe' shape, whilst the other has them in the shape of a Circle.

I've come across both types of 8 pin DIN (outer pins in a circle, or 2 pins offset from the circle), but never seen anything other than the 'circular pinned' 7 pin DIN. Where was it used?

bikerhifinut · 3rd Mar 2018, 12:46 am

I've got a couple of 7 pin extenders.
They are part of my "Autocom" motorbike comms system.

https://www.autocom-shop.co.uk/produ...lead-straight/

You won't like the price though!

That said they are waterproofed "Click lock" plugs and sockets for heavy duty use.

But I made my own custom leads up for a permanent fit to the bike and saved a fair bit.

A.

camtechman · 3rd Mar 2018, 11:43 am

There is also another rarer 7 pin DIN plug & chassis socket, mainly used on ITT cassette recorders.

It has a longer metal shroud which activates a switch within the chassis socket and used with their microphones with a remote switch. The same combination is also used on a Grundig C200 deluxe cassette recorder & GDM 305 microphone.

ben · 3rd Mar 2018, 2:14 pm

I was going to say car cd changer cable. I have one somewhere and I am sure it has male one end female t'other. like this

Dave Moll · 3rd Mar 2018, 2:30 pm

The one in the above link is eight-pin.

Radio Wrangler · 3rd Mar 2018, 2:49 pm

Not all extenders connect all the pins. Buying anything which has a 7 pin plug at one end and a 7 pin socket at the other won't necessarily work.

The only certain approach is to slide back the plastic cover of the cable you have and see what needs to be connected.

Sometimes you'll find several cores inside a single braided screen, sometimes you'll find cores in individual screens. You have to look to be sure.

David

Goldie99 · 3rd Mar 2018, 4:39 pm

Or, if you prefer the comfort of your desk - the full schematics & service manuals are on the hifiengine.com website. From a very quick glance, it looks like there's only 4 terminals actually in use.

Dai Corner · 3rd Mar 2018, 5:47 pm

Given the incremental design of DIN plugs, would an 8 pin to extension lead work (perhaps with a little surgery to the male end to remove one pin)?

This ebay seller claims his 8 pin lead can also be used for 5 and 7 pin applications and is fully wired (example, not endoresement).

https://www.ebay.co.uk/i/292002935121

https://www.ebay.co.uk/i/291950834650

Dave Moll · 3rd Mar 2018, 10:45 pm

I would have thought that an eight-pin plug with the centre (eighth) pin amputated should fit in a seven-pin socket - and there shouldn't be any problem in the other direction.

2nd Mar 2018, 11:39 am	#1
placemat Triode Join Date: May 2016 Location: Birmingham, West Midlands, UK. Posts: 47	7 Pin Din Wiring help... Hello! I have a Revox PR99 MKII reel to reel that also has the Revox monitor speaker with it. It connects via the 7 pin din cable which is long enough if both items are set up in the rack, but I have since taken the PR 99 out of the rack and placed it upright with the monitor speaker on the shelf above. The seven pin audio cable now will not reach. I have looked everywhere to see if there are any seven pin din extension cables, but I've had no luck. I can easily get seven pin din male and female plug ends, but I'm not sure what type of cable it is or how to wire them up correctly. If anyone can help, I will be very grateful. I've attached an image of the plug that I need to extend. Attached Thumbnails

2nd Mar 2018, 12:13 pm	#2
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,675	Re: 7 Pin Din Wiring help... Simplest way to do this is to slide back the cover and remove the shell from the existing plug - this will show you which, and how many, pins are being used. Then all you need is screened cable with enough cores, and away you go. You just need to wire the extender pin-for-pin, but make sure you connect the screen to the right pin - this is usually pin 2 which, confusingly, is the middle pin...!

2nd Mar 2018, 2:02 pm	#3
placemat Triode Join Date: May 2016 Location: Birmingham, West Midlands, UK. Posts: 47	Re: 7 Pin Din Wiring help... Many thanks Ted, It's such a shame that I cannot find a male to female cable or even a female to female adapter. I have exactly this for a five pin din audio cable, but finding it for seven pin is near impossible! Many thanks again for your help. Steve.

2nd Mar 2018, 5:57 pm	#5
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: 7 Pin Din Wiring help... This may be irrelevant, but Blaupunkt at one time used 7 & 8 pin DIN connectors with their car stereos and amplifiers. In those a multicore cable with an overall outer screen was used. No doubt necessary in a vehicle, an overall screen may not be essential for domestic use. A complication is that there are or were, two types of 7-pin DIN connector - in one the pins are arranged in a kind of 'horseshoe' shape, whilst the other has them in the shape of a Circle.

2nd Mar 2018, 6:11 pm	#6
dseymo1 Retired Dormant Member Join Date: Dec 2007 Location: Shropshire, UK. Posts: 3,051	Re: 7 Pin Din Wiring help... You'll also need a steady hand and good eyesight - horrible things to wire

2nd Mar 2018, 6:11 pm	#7
emeritus Dekatron Join Date: Jan 2012 Location: Brentwood, Essex, UK. Posts: 5,345	Re: 7 Pin Din Wiring help... The 7 pin DIN with all pins on a circle is sometimes found on Philips cassette recorders, but only a 5 pin plug is needed: the two extra pins are generally connected directly to the record/playback head and are presumably only used during manufacture for adjustment. I have never come across a 7 pin extension lead or any back-to-back adapters, but Maplin always used to stock the plugs.

3rd Mar 2018, 12:46 am	#9
bikerhifinut Octode Join Date: Nov 2013 Location: Penrith, Cumbria, UK Posts: 1,993	Re: 7 Pin Din Wiring help... I've got a couple of 7 pin extenders. They are part of my "Autocom" motorbike comms system. https://www.autocom-shop.co.uk/produ...lead-straight/ You won't like the price though! That said they are waterproofed "Click lock" plugs and sockets for heavy duty use. But I made my own custom leads up for a permanent fit to the bike and saved a fair bit. A.

3rd Mar 2018, 11:43 am	#10
camtechman Nonode Join Date: Jan 2008 Location: Milton Keynes, Bucks. UK. Posts: 2,552	Re: 7 Pin Din Wiring help... There is also another rarer 7 pin DIN plug & chassis socket, mainly used on ITT cassette recorders. It has a longer metal shroud which activates a switch within the chassis socket and used with their microphones with a remote switch. The same combination is also used on a Grundig C200 deluxe cassette recorder & GDM 305 microphone. Attached Thumbnails __________________ When I die, please don't let my Wife sell my collection for the amount I told her I paid for it!

3rd Mar 2018, 2:14 pm	#11
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: 7 Pin Din Wiring help... I was going to say car cd changer cable. I have one somewhere and I am sure it has male one end female t'other. like this __________________ Regards, Ben.

3rd Mar 2018, 2:30 pm	#12
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: 7 Pin Din Wiring help... The one in the above link is eight-pin. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

3rd Mar 2018, 2:49 pm	#13
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,899	Re: 7 Pin Din Wiring help... Not all extenders connect all the pins. Buying anything which has a 7 pin plug at one end and a 7 pin socket at the other won't necessarily work. The only certain approach is to slide back the plastic cover of the cable you have and see what needs to be connected. Sometimes you'll find several cores inside a single braided screen, sometimes you'll find cores in individual screens. You have to look to be sure. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

3rd Mar 2018, 4:39 pm	#14
Goldie99 Heptode Join Date: Jul 2014 Location: Boston, Lincolnshire, UK. Posts: 995	Re: 7 Pin Din Wiring help... Or, if you prefer the comfort of your desk - the full schematics & service manuals are on the hifiengine.com website. From a very quick glance, it looks like there's only 4 terminals actually in use.

3rd Mar 2018, 5:47 pm	#15
Dai Corner Hexode Join Date: Oct 2016 Location: Newport, South Wales, UK. Posts: 278	Re: 7 Pin Din Wiring help... Given the incremental design of DIN plugs, would an 8 pin to extension lead work (perhaps with a little surgery to the male end to remove one pin)? This ebay seller claims his 8 pin lead can also be used for 5 and 7 pin applications and is fully wired (example, not endoresement). https://www.ebay.co.uk/i/292002935121 https://www.ebay.co.uk/i/291950834650

3rd Mar 2018, 10:45 pm	#16
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: 7 Pin Din Wiring help... I would have thought that an eight-pin plug with the centre (eighth) pin amputated should fit in a seven-pin socket - and there shouldn't be any problem in the other direction. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)