Confusion over DIN sockets
 

My Leak Delta 30 amplifier has a 5 pin DIN socket on the front panel for use with a tape deck. I would like to buy or make up a lead to take an output from the amp to feed into a vintage Grundig tape recorder. I have drawn a diagram of the input and output connections on this socket (looking at the face of the socket). My question is, what are the input pins on the Grundig DIN sockets. The machines are models TK14 and TK18.

Re: Confusion over DIN sockets
 

pins 1, 4 and 2 for a stereo connection

Re: Confusion over DIN sockets
 

Screen grab below taken from the TK14 manual that is available as a free download from:https://elektrotanya.com/grundig_tk1.../download.html

Re: Confusion over DIN sockets
 

Because the Grundig is a mono recorder, Pin 1 must be joined to pin 4, and pin 3 to pin 5 in the 5-pin DIN plug at the end plugged into the Delta 30, or, if the amplifier is opened, the pins can be joined as above on the DIN Socket. The only drawback to this is that, although this mod. is reversible, unless this is done, if, in the future a stereo tape recorder is used, any recordings made will only be mono.
A.F.A.I.K. No harm will result to the amplifier by bridging the channels at the DIN socket as described, but perhaps other members would like to advise of any possible snags involved (I don't have a Delta 3o circuit diagram to hand)

Re: Confusion over DIN sockets
 

Surely you just need a mono (3 pin) lead, and you switch the amp to mono when recording? 3 pin is compatible with 5 pin, but you only get the left hand channel. The connectors were originally a mono design and were extended to support stereo, which is why the pin numbering of the 5 pin plugs is so odd.

Re: Confusion over DIN sockets
 

Didn’t the DIN standard specify input and output pins swapped between amplifiers and tape recorders?

The standard I have (and B&O amplifier and JVC cassette recorder manuals) show

Amplifier: inputs 3 & 5, outputs 1 & 4
Tape recorder: inputs 1 & 4, outputs 3 & 5.

So a “standard” lead would connect pins 1 to 1, 2 to 2 (earth), 3 to 3 etc.

To connect two tape recorders together, you needed a special crossed lead.

Stuart

Re: Confusion over DIN sockets
 

Quite so.

Re: Confusion over DIN sockets
 

Thanks for all your replies. I've never liked DIN sockets but the one on the front of the amp is handy for occasional use with a tape recorder. Studying the circuit diagram for the TK14, the machine doesn't seem to have a Line input, or a Line output either. Pin 1 of the "Radio/diode" socket goes to earth via a couple of 22k resistors, while pin 3 connects to the ECL86 triode's anode via a 220k resistor and 0.1uF capacitor. I can't imagine what this socket would be used for. The socket marked on the circuit diagram as "output" is for a speaker. It seems that with the TK14 the only way to make a "direct" recording would be to use the microphone input with a suitable attenuator circuit. The arrangement of DIN sockets on the TK18 is very similar to that of the TK14. Mono operation wouldn't be a problem as the amp has switching to select either Left/Right input or mono.

Re: Confusion over DIN sockets
 

'Radio/diode' is Grundig terminology for a line input or output. It derives from the probable use of a radio as a signal source or external amplifier. The signal would come from / go to the top of the volume control, after the detector diode.

I don't know the recorder being discussed so can't help with specifics.

Re: Confusion over DIN sockets
 

Thank you for clarifying that. Pin 3 of this socket could well be a low level output but would be affected by the setting of the volume control. There doesn't seem to be an input on this socket though. I've been working with consumer electronics for nearly half a century and Grundig circuits still baffle me.

Regards
Martin

Re: Confusion over DIN sockets
 

The socket in question would normally be expected to provide both an input and an output, but I don't have a circuit to confirm that. Is it possible that it's been 'got at'?

Re: Confusion over DIN sockets
 

Pin 1 on the leftmost socket is a low level input (@'2mV').

Pin 1 on the middle socket is a high level input (@'80mV'), potted down via a 1M and a 22k to be comparable with the low level input.

The inputs are selected via switch '2' which is shown in the low level position, with the potted down high level input shorted to ground.

The switches look rather like 'links' in the circuit diagram, which may be a source of confusion ?

Cheers

Re: Confusion over DIN sockets
 

Thank you Trigon, you have cleared up my confusion. I didn't realise the "links" on the circuit diagram were switch contacts. Paul, you are correct. The "radio/diode" socket does have an input and an output. There are 3 inputs in total. A low level microphone input, a high level input potted down by a 1M and 22K resistor and another input potted down by two 22K resistors. There is also an output from the anode of the ECL86 audio amp triode that goes via a 0.1uF cap and is attenuated by a 220k and a 15k resistor. Thanks again to everyone who has replied.

Regards
Martin

Re: Confusion over DIN sockets
 

There seems to have been some changes down the line. The diagrams below are from the TK14 manual Issue 1:-

Attachment 178087 Attachment 178088

https://www.vintageshifi.com/reperto...ice-Manual.pdf

Cheers

Re: Confusion over DIN sockets
 

I see what you mean. I will just make up a couple of mono DIN leads, one "straight" and the other with crossed over connections and one of them should work. All I wanted to do was make up a few tapes recorded from 1960s vinyl records, complete with a little surface noise here and there. Pure nostalgia.

Regards
Martin

Re: Confusion over DIN sockets
 

you only need a mirror image lead to
play / record from one tape recorder to another tape recorder

Re: Confusion over DIN sockets
 

Hi, a "straight" 3 pin to 5 Pin DIN lead, such as was supplied with many Philips reel to reel and Cassette machines, should suffice between your Amplifier DIN socket and your TK14 'Diode' Socket (the centre one of the three on the socket panel)

If you find that the output from the Amplifier is too low when connecting to the Diode socket, i.e. you have to set the recording level control close to maximum, use the microphone DIN socket instead (farthest right socket when viewed from the rear of the machine) and ensure that you operate the 'MICRO' key next to the STOP key on the tape transport controls.

For playback through your amplifier you MUST connect the DIN lead to the Diode (centre) socket and the output will be dependent on the setting of the TK14's volume control.

Regards

Andrew

Re: Confusion over DIN sockets
 

Thanks Andrew. I will make up or buy a "straight" DIN lead. The amp has the usual rear RCA phono sockets but the front panel socket is handy for occasional use with a vintage tape recorder.

Regards
Martin

Re: Confusion over DIN sockets
 

Hi again, a 5 Pin to 5 Pin stereo lead may be OK to use as some of the Grundig recorders had dummy holes on the 3 Pin DIN sockets to allow a 5 pin plug to be inserted (best to check though)

As already mentioned if using a 5 pin to 5 pin lead you will have to operate the Mono switch on your amplifier.

Also the Micro key is next to the TEMP STOP key and not the Stop key on the tape transport controls (I was going from memory till I saw a picture of a TK14)

Andrew