Mystery German modules - Help me get them going!

So, i have had these modules for a very long time on my shelf and have been looking at them now and then but never made a good try to get them up and running.
The modules themseves must be from some kind of German modular mixer from the late 60´s and i have never seen anything like them.
They are massive (included a Neve 1272 style module for size comparison) and the buildquality is quite impressive, space was not an issue 
Many modules have a symbol on the front that i have asked here about before but no one knew what it was then.
There are micpre/es, compressors, a tone generator, plate drivers and also a Vocoder among the modules that i have.
Would love to hear if you know anything about them.

But lets move on to the electronics.
I took a good look at them today and i can not figure out the power arrangement.
The connectors are the same 12 pin Tuchels as on V modules but not sure if they run on 220v or not.
Most of them have what looks like dual powertransformers (or possibly dual outputs) and there is also a separate powerfeed on pin 4A.
The "powertransformers" are connected to pins 6A + 6B (like the 220v on the V modules) and pins 5A + 5B or 3A + 3B depending on the module.
After the transformers there are what looks like output stages so maybe i am wrong about the power thing and there are dual outputs in the modules?
That would most likely be the most logical thing i guess but i am not sure, then there would be two inputs as well since there are two identical shielded cans, stereo?

The feed on pin 4A on all modules first goes to a 0,2A fuse, then to a powerdiode and electrolytics that are rated for 35v.
After that to a 2n3054 or 2n3055 transistor.
I guess my main question is where i should start to try to power them up.
Would 24v on pin 4A be a safe bet?

Several pictures below of three different modules.
First is a Micpre/eq
Second is a dual compressor
Third is another micpre/eq but quite different circuit than the first (this is unbranded but have a modelnumber).

"DUAL BEGRENZER"

Different version of the Micpre/eq with less transformers.

API, it is a fun puzzle. 

It is a bit confusing because
1) I can't tell which modules or psu's are which in the guts pictures.
2) The guts pictures are not complete (close up's are fine but for instance where does the cable go in http://www.9voltstudio.se/german_mystery/german_mystery_15.jpg)? 
3) Photo's from the three modules are bundled together so it is difficult to tell which module is which.

Might be easier if you edited the posts to group one module per post, and provided full front and back as reference photos on each post.

Well from the Name Bergrenzer...They are german limiters

http://en.bab.la/dictionary/german-english/begrenzer

Possibly of the Broadcast Variety

Very nice construction, in fact beautiful audio electroart !!
Schematics would be essential if I were to power these, or some primary schematic rev engineering drawing.

I would hate to see those smoke !

Wow, 16 trimpots in the "DUAL BEGRENZER"...
This gives the impression that it is a rather critical circuit, might be a crime to align properly!
(Looks nice by the way, ELMA switches?)

bruce0 said:

2) The guts pictures are not complete (close up's are fine but for instance where does the cable go in http://www.9voltstudio.se/german_mystery/german_mystery_15.jpg)? 
3) Photo's from the three modules are bundled together so it is difficult to tell which module is which.

Might be easier if you edited the posts to group one module per post, and provided full front and back as reference photos on each post.

Click to expand...

That is actually what i did, each post has a different module, only the first one show the front of the three modules.
Maybe i should include a pic of hte frontpanel of each module to the post.

The cable you are refering to goes directly to the gainswitch, not sure if this is original since this module have been modified.

And yes, they are obviously german, which i also wrote in my first post, all the writing on the fronts are in German.

Logo appears to be the Letter G surrounding the letter K with a little V added on (gkv gvk kgv kvg vkg vgk).  Any of these make sense to anyone?

Hi,

it's definitely German!
Now the question is East or West Germany?
"MV-xx" was mostly used in East Germany, e.g. MV 810, MV 4056.
(The component identification code was different between East and West so google may help you...
--- looks like they're mostly West German, that's wired...)

Maybe from that point you can make a derivation of the pin connections!?  :-\

ROCK-ON!

Dr_J said:

Hi,

it's definitely German!
Now the question is East or West Germany?
"MV-xx" was mostly used in East Germany, e.g. MV 810, MV 4056.
(The component identification code was different between East and West so google may help you...
--- looks like they're mostly West German, that's wired...)

Maybe from that point you can make a derivation of the pin connections!?  :-\

ROCK-ON!

Click to expand...

I agree. Maybe this units was custom made for one of the east german broadcasting stations in the transition time after the fall of the wall??

I would bet on East!  LOST it...  :-[

East with some West components (transistors) ... resistors looking to me more being East... as well soldering and wiring...
Although the pin connector can tell you a story...
But do a google on the components...

For powering up, check polarization of the power circuit caps and 20V will be a good starting point, IMHO.

ROCK-ON!

On one of the green elcos there is written "W-Germany" (west) and together with the expensive elma switches I guess it is from the western part of this country. Beautiful workmanship I'd say, those mu metal cans for the transformers look like the ones in the v76, expensive stuff….
But I have never seen those things before and without a schematic is it hard to say what is going on inside…

The golden elcos a west-german too. There are DIN numbers on it.

damn why modern stuff does not look so cool.  :-\

I was surprised by the strange way they have mounted the electrolytic capacitors: glued in a hole in the PCB while the minus is attached to a solder lug on a screw!.

I'm sure it's west german, maybe custom built for a big studio like teldec in Berlin. I once bought a box full of modules from teldec which look similar, it was a quadrophonic desk

Could be Austrian or Swiss too.

PCB type and transformer hardware looks like inside Neumann PV76/PEV modules: My schematics on these say 1968.

Do I see transistor date codes from '68? If so, it may have been refurbed with new elma rotary switches later (don't think the blue Elma's were around till late-70'es). And Kyroitsu KM-48 meters were more late 70'es and early 80'es technology.

We haven't seen these in studio/broadcast electronics before, so they are probably custom made.

Live stuff wouldn't require this quality level, or pay the resulting prize.

So my guess is a custom job for a south-German theater installation - mid-70'es  ;D

Jakob E.

Its West.
In East they had own brand of caps.
(Frolyt - still in bussines)

RuudNL said:

I was surprised by the strange way they have mounted the electrolytic capacitors: glued in a hole in the PCB while the minus is attached to a solder lug on a screw!.

Click to expand...

thats what you would call a 'through hole' component  ;D


German, Broadcast, probably early transitor units - they do have the Tuchel 12 pin connector, but most probably with 24v. but not shure. good info here, but I haven't foung your manufacurer / model....

http://audio.kubarth.com/rundfunk/index.cgi


- Michael

by the way, how many poles are there on the Tuchel connector?

audiomixer said:

RuudNL said:

I was surprised by the strange way they have mounted the electrolytic capacitors: glued in a hole in the PCB while the minus is attached to a solder lug on a screw!.

Click to expand...

thats what you would call a 'through-hole' component  ;D

- Michael

by the way, how many poles are there on the Tuchel connector?

Click to expand...

;D Yes, the ultimate thru hole components!
Very strange way to mount a cap, especially with all that space inside.

But thanks for all the great comments so far!
I am also pretty sure that the are W-German, transistors are mostly TI and RCA, diodes from ITT, filmcaps are Wima and Siemens, Elma switches etc all points to being western.
The datecodes i have found are from the 1968-72 period, the modded micpre/eq seems the oldest of the bunch, and i believe i have those blue Elmas in early 70´s Cadacs so the must have been availible in that timeframe.

What do you guys think about the transformers?
I am starting to believe that the ones i thought was power from the start are indeed outputs.
I got some more clues today when i opened up a stereoplate driver and the Vocoder, both have a power in on pin 4A like the rest going to 35v rated caps.
The Stereoplate driver have similar transformers as the Micpre and in this module they are clearly outputs since they are connected to the two output cards.
But why does a micpre have dual output stages?
Maybe a balanced insert between the pre and eq??

In the stereoplate module there are some 3rd party cards marked "RIM Electronics" which has small Beyer transformers on them.
Anyone heard about them before?

Either way, the modules seem like a custom build, all modules look handbuilt, especially the "odd" ones like the Vocoder.
Would love to know more and find some schematics.
But will try to hook one up to a 24v supply and see what happens.

Connectors are 12 pole Tuchels and from what i can see this is the pinout roughly used, it differs a bit between the modules since a few have more in and outs on pins 2AB, 3AB and 5AB.

1A - Output +
1B - Output -
2A -
2B -
3A -
3B - Ground
4A - +24v
4B - Ground
5A -
5B -
6A - Input +
6B - Input -

Vocoder and Stereohall driver:


Stereohall driver:


Vocoder: