Recording with a Phillips N4307 tape recorder

[sayalon]

Hi there all,

I recently acquired a working Phillips N4307 reel-to-reel 4-track tape recorder, and would like to ask some potentially dumb questions about it.

I can see that at the back it has a 6-pin DIN connector labelled radio/micro/phono. I was wondering how I would go about recording into this from my computers soundcard? My plan was to play electric guitar into the soundcard, which has a built in preamp, and then I'd go out from the soundcard into the tape recorder. What would be the best way to go about doing this, and using what converters?

I've looked around on this forum, and online, and I can see that DIN to 3.5mm converters can be bought, but I don't know for sure if they use the correct pins etc. I presume I would also need multiple converters - one that allows input and one that allows output? I've also noticed that most of these converters have 5 pins, where this has 6 pins?

Finally, there's a switch on the back that gives the choice between 4 and 8 ohms. How do I know which of these to switch to when eventually hooking this up to speakers, or feeding into my soundcard?

Thanks in advance for your help/tolerance

[dazzlevision]

My plan was to play electric guitar into the soundcard, which has a built in preamp, and then I'd go out from the soundcard into the tape recorder. What would be the best way to go about doing this, and using what converters?

Finally, there's a switch on the back that gives the choice between 4 and 8 ohms. How do I know which of these to switch to when eventually hooking this up to speakers, or feeding into my soundcard?

If your guitar has a built-in preamp, then you should, with a suitable connecting lead, be able to go straight from the guitar into the tape recorder's "phono" (i.e. accepts a relatively high input signal level, in the order of a hundred millivolts) input socket. Does your guitar have a standard 0.25" (quarter inch) diameter "Jack" socket?

If you want to feed the recorded guitar into your sound card, you shouldn't need to use the "speaker" output, but the lower level output from the "radio" DIN socket (around 750 millivolts).

Note that the tape recorder's "radio/phono" socket accepts both an input (when set to record) and provides output (on playback), on separate pins (with pin 2 being common and which goes to the screen of the connecting cable). You should get a better quality output from the radio socket, rather than the speaker socket.

I doubt you'll be able to buy suitable ready made up leads, so you may have to make them yourself (or get "A N Other" to).

[TonyDuell]

This is, of course, a mono machine, recording on one track at a time.

I've just looked at the service manual, and it confirmed what I suspected. That 6 pin DIN socket is a Philips special but the middle pin is used only as a test point when repairing the machine. The common 5 pin DIN plugs (180 degree type) and adapters will fit and make all the connections you need.

The wiring is standard. Pins 1 and 4 are the record input signal (the 2 pins are effectivel the same), pins 3 and 5 are the playback signal, and pin 2 is ground.

[julie_m]

Can you post a picture of the socket panel on the recorder, please?

It's unusual for a 6-pin (240°) DIN socket to be used for audio, but it's not inconceivable for this to be a 5-pin (180°) socket with an added centre hole for some Philips-ish purpose (perhaps carrying power to some proprietary accessory). In which case, pin 1 will be the mic input (low impedance, high sensitivity) and pin 3 will be the radio/phono input (high impedance, low sensitivity) during recording and an audio output during playback. Pin 2 will of course be the common earth return.

[TonyDuell]

That's basically what I said. According to the service manual, it is a normal 180 degree 5 pin socket with an extra pin in the middle. That pin is labelled 'MP1' (Monitor Point) on the circuit diagram. It's connected to the 'bottom end' of the record/playback head (low value resistor to ground) and is, I think, used when setting the bias level. It is not for normal use.

So all you need is a 5 pin DIN plug.

In record mode, pins 1 and 4 (which are linked) are, indeed, the microphone input. Pin 3 (but oddly not pin 5) can be used as a higher level input. On playback, pins 3 and 5 are linked and are a line-level output. Personally when using recorders like this, I use 1 and 4 as the record input with an external attenuating resistor.

[emeritus]

My EL3302 cassette recorder also has one of those 6 pin 180 degree DIN sockets. The centre pin is likewise used to make a connection to the record/playback head as per #5, and so can be ignored for normal use.

[dazzlevision]

Originally Posted by TonyDuell

In record mode, pins 1 and 4 (which are linked) are, indeed, the microphone input. Pin 3 (but oddly not pin 5) can be used as a higher level input. On playback, pins 3 and 5 are linked and are a line-level output. Personally when using recorders like this, I use 1 and 4 as the record input with an external attenuating resistor.

Indeed. Philips supplied a connecting lead with many of their 1960s tape recorders, with a three pin 180 degrees DIN plug at one end and tinned bare wires at the other. The DIN plug had a tiny 1Meg resistor in it, to attenuate the input signal when not using a mike.

[julie_m]

Sorry, Tony. I must have missed your post, due to starting mine and then getting summoned away to dinner before I finished typing it.

Interesting test point to bring out via a special non-standard socket, though .....

[TonyDuell]

Bringing that testpoint out in that way was not uncommon on Philips tape recorders. I am not sure a plug was ever sold to connect to it (just stick the 'scope probe in the hole), but I guess one was used at the factory.

My N4450 (stereo, separate record and playback heads) brings out similar test points for the record and playback (why?) heads on pins 6 and 7 of normal 7 pin DIN sockets where pins 1-5 are used for normal audio functions.