Uher 4400 IC and Sony F-99EX mic

[kfeuerherm]

Greetings,

I recently acquired a Uher 4400 IC machine. I had ordered the Uher mics to go with it, but the 'helpful' vendor decided it would be more convenient for me to have the Sony F-99EX stereo mic and shipped that instead.... Unfortunate, because the point is for me to do demos of authentic analogue equipement in a first year university class....

I have two problems. First, I can't seem to record anything.

I've read the manual (in German and French), tried various configurations, and I've read a few other threads on this forum, but somehow the details don't seem to match, so I've attached pictures for clarity's sake.

I have two each of the plug conversion items shown. As per label, the mic is rated 500 Ohm impedance "one point stereo dynamic microphone" (whatever that means!).

In all cases, I have the mic plugged into the first type of adapter; then have tried plugging the red and/or white female jacks into black, yellow, white, red females (either just one or both) on the DIN adaptor using the MICRO1 socket, or one into MICRO1 and one into MICRO2, or even using the RADIO/PHONO input on the side.

No matter what I try, only connecting to the black female seems to produce any results (in terms of sound being picked up and played over the internal speaker), but ultimately when releasing PAUSE (after having PLAY and RECORD pressed down), the original recording is not replaced.

I presume that it's a question of getting the exactly right combination but I don't know what that is! Some threads suggest it can all be done through either MICRO1 or MICRO2 by switching, but I don't see how to do that....

My other problem is that playback is fine as far as I can tell (the tape that came with it has some 'period' prerecorded stuff, very old recording I would guess) over the internal speaker (if not high quality), but when plugging in my speakers (see the other two photos) I have the *impression* that one speaker is playing normally but the other is playing something backwards.... I assume I'm dreaming and to be honest I didn't expect this to work at all; but I had the speakers from way back....

Any help to get me going would be appreciated. I'm not very literate about such things unfortunately and I'm in Canada if it matters.

Thanks so much!

[TonyDuell]

I hope I don't insult you by stating the obvious....

Firstly the microphone name. '500 Ohms impedance' is specifying an electrical property (impedance is like resistance, but generalised to cover AC circuits) of the unit. 'Stereo' means it has 2 microphone elements inside and can thus output the left and right channel signals for a stereo recording. 'Dynamic' is the same as 'moving coil', the microphone works like a loudspeaker in reverse, the incoming sound waves vibrate a diaphragm which moves a tiny coil of wire in a magnetic field, this induces a small electrical voltage in the coil, that's the signal that goes to the tape recorder. The 'one point' was a Sony name meaning you just had one thing to point at the sound you were recording, rather than having to use separate microphones for the 2 stereo channels and setting them all up.

The microphone plug has 3 contacts, starting at the body of the plug they will be ground, right channel, left channel. When plugged into that adapter lead with the red and white RCA phono plugs, the white plug will carry the left channel signal, the red plug will carry the right channel signal (and the outer of both plugs will be ground).


A stereo recording has 2 independant signals, one for the left channel, one for the right channel. In the case of a tape recorder there are effectively 2 sets of electronics (one for each channel). I have looked at the service manual for this machine, and it appears that while the 5 pin 'radio' DIN socket carries both channels (both inputs and outputs, the 5 pins are the 2 input signals the 2 output signals and a common ground), each microphone socket is for one channel only. That's why there are 2 sockets. So to record in stereo, you have to have something plugged into each socket.

Now those microphone sockets have 7 contacts. Owing to the way the socket evolved from a 5 pin, which itself came from a 3 pin, the pins numbers are not in the obvious order. Starting at the keyway and going clockwise, they are 6, 1, 4, 2, 5, 3, 7. According to the manual, pin 2 (the middle one) is ground -- it almost always is on audio connectors) and pin 3 is the signal.

Your second adapter lead will have a 5 pin plug on one end (this makes contact wit pins 1-5 of the socket, nothing connects to the outside 2 -- 6 and 7). And 4 phono sockets on the other. The outers of all 4 phono sockets will be wired to pin 2 (that's what you want -- ground) and the inners to the other 4 pins , one socket for each pin). That explains why only one socket (the black one), presumably with the centre contact going to pin 3 of the DIN plug, works.

So I think you need 2 such adapter leads. One in Micro 1, the other in Micro 2. Microphone to the first adapter cable you have, white plug of that to the black socket of the cable in Micro 1, red plug to the black socket of the cable in Micro 2.

Of course there may be other problems with the machine, or how you use it, but that's how I would connect everythng up.

[TonyDuell]

Now for the second problem. It is quite possible that the second channel (right hand channel) will be playing something backwards if the tape was recorded on another machine.

The reason is that a lot of tape recorders were mono, they record one signal at a time. To economise on tape use, they would record using the top half of the tape width only. At the end of the tape you turned the spools over, and recorded again. This uses what was the bottom half of the tape in the opposite direction.

So at the end, you have a recording on the top half of the tape and a different recording going the other way on the bottom half of the tape.

Now stereo machines, as I said, need to record 2 signals at once. Many divided the tape into 4 quarters across the width. If we number them 1 at the top and 4 at the bottom, then 1 was used for the left signal and 3 (NOT 2) for the right signal. At the end, again you would turn the spools over and use the other 2 'tracks' (as they are called).

(As an aside, such machines could almost always (always?) record in mono using one of the 2 tracks available in that driection. So you could record in track 1 or 3 with the tape going one way, flip the tape over at the end and record on 4 or 2. So you could fit 4 mono recordings on the tape. There will be switches to do this.)

Now, think what happens if you put a mono tape recorded on the first type of machine (a '2 track recorder') on your machine (a '4 track recorder') and play it in stereo. The left playback head (the bit that senses the magnetic recording on the tape) will play half the top track of the tape (the other half of that track is ignored, but that doesn't matter). That's the signal you want. But the right playback head will be playing part of the second track on the tape (it's 3/4s the way down the tape, in the second half where the second track is). That track, on a 2 track machine, was recorded the other way. So it will play backwards.

You can play such tapes on the machine -- in mono (as that's what they were recorded as , you can't generate a second channel from nowhere) -- if you switch the machine to only play track 1.

[kfeuerherm]

Hi Tony,

No worries... Yes, I do understand impedance and stereo. Those bits I gave because I understand there are two types of microphones (balanced and not) and I thought this might be useful info. I do know how a mic works but I didn't know the meaning of 'dynamic' so thanks for that I appreciate your thoroughness.

Next para, thanks, that makes sense.

About sockets. That's precisely what I expected. Hence I was surprised when I was investigating that on another thread it was suggested that one could somehow do it all with just either MICRO1 or MICRO2!

Thanks for the details of the pin assignments. That is helpful! I figured that there had to be some common wirings, just didn't know how it was done.

I suspect I tried this combination, but I will do so again. The machine was supposed to be in working order when it was shipped, but who knows.

Thanks very much for the time you put into this! If I make some headway, I'll be sure to report back

Karljürgen

[kfeuerherm]

Hi again,

Yes, I get this. What is puzzling is that when I use the internal speakers, I get a normal effect; when I use external ones, I get the peculiar effect. *That's* what I find odd.

I surmised it might be due to misaligned tracks, and you confirm this possiblity. Still, the heads and tracks would align the same way regardless of which speaker(s) is/are used....

In any case: I don't need the existing recordings, so if I can overcome the first problem and playback is good, then all is well. I just thought I'd mention this effect while I'm at it.

Much appreciated once again.

K

[TonyDuell]

Originally Posted by kfeuerherm

Yes, I get this. What is puzzling is that when I use the internal speakers, I get a normal effect; when I use external ones, I get the peculiar effect. *That's* what I find odd.

According to the schematic/circuit diagram there are 2 power amplifiers in this machine (to 2 drive 2 external speakers) but only one internal speaker, which seems to play (at least by default) the left channel (track 1). So if I am right about you playing a 2-track mono tape on this machine that would explain why you only get this 'backwards' signal on external speakers.

[TonyDuell]

Originally Posted by kfeuerherm

About sockets. That's precisely what I expected. Hence I was surprised when I was investigating that on another thread it was suggested that one could somehow do it all with just either MICRO1 or MICRO2!

Thanks for the details of the pin assignments. That is helpful! I figured that there had to be some common wirings, just didn't know how it was done.

I suspect I tried this combination, but I will do so again. The machine was supposed to be in working order when it was shipped, but who knows.

Thanks very much for the time you put into this! If I make some headway, I'll be sure to report back

Your microphone is 'unbalanced' as is the input on the machine.

I have checked the schematic again and I can see no way that the second channel input appears on MICRO 1 (or vice versa). Of course there may have been a factory change where said signal was on pin of the 'other' socket on machines after a certain serial number but the manual I have doesn't mention it. I would assume thats not the case, and use both sockets.

I find the only way to get something like this working is to get each bit right (say the microphone connections) and then see what else could be the problem. It's entirely possible there is a fault in the machine, or you're not operating it properly. Do you have the user and/or service manuals for it?

[kfeuerherm]

Ok... thanks for both those things.

I tried your suggestion. No response except to the MICRO1 input, and regardless, nothing is recorded. Playback gets me the same thing that was there to begin with. (It shouldn't matter I wouldn't think, but for good measure, I tried altering the track selections and varying the speeds, no luck so far. Just in case it's some quirk or other. I did notice that I can't test the battery levels except when it's in record mode, which makes no sense...)

As you say, something's not tallying, assuming that the thing worked when it was shipped, as I was assured it did.... (and it only shipped from France to Germany; my brother brought it the rest of the way so I would think shipping damage likelihood would be small. But who knows!)

I've just mounted an old tape that's been in my family since the 60s, though, and it plays back very nicely--much better than what' on the tape that came with the machine! So at least there's that...

Now, as for manuals: yes, I have user manuals in French and German (can't find an English one) and I do have a service manual as well. I looked at it briefly but didn't get far with it....

K

[TonyDuell]

If you are monitoring the recording signal using the internal speaker then I think it only monitors the MICRO1 channel (left channel). Try connecting your external speakers to see if MICRO2 works on the right channel external speaker. If it does, try recording like that and playing back on the external speakers. It's possible that one channel will work and the other not.

It is possible there is an electronic fault that affects both channels (if neither is recording properly). 'Works' can mean different things to different people, it's possilb that the seller saw the spools go round and noise came out of the speaker and thought it must be working properly without testing the recording function.

[kfeuerherm]

Only time for a short test, plugged in the speakers, didn't make it possible to record. I found that I had to have the levels way up to get the left needle to move even half way and the right needle never moved at all. I'll come back to this in a few days and do a more systematic test.

I did have an in-depth discussion with the vendor at the time, and apparently it was recording then. He did say to contact him as there were some 'particularities' about the machine; I've done that but no response yet.

By the way, here's the odd quote I referred to earlier: "Don't be fooled by the fact that they are 8-pin connectors; the inputs are standard 3-pin DIN plugs for mono mics, or you can plug in a stereo mic with a 5-pin DIN connector to one of the connectors, with the microphone mode selector switch in the appropriate position." (italics mine). The thread is here if you're curious: https://www.vintage-radio.net/forum/...ad.php?t=38246 It suggests that there was a certain variation in these machines....

Thanks again for your help thus far.