JeromeMason

Need info on Telefunken Pre
« on: May 25, 2015, 08:37:12 PM »
Hey guys, I'm trying to desperately find some information about this little pre. It's Siemens, and I can't tell the age but I'm trying to find the pinout to at least see how it sounds and determine the gain of it. Looks to be the size of a 500 series unit and might of come out of a portable mixer or something. If anyone can give me any info that will help me dig further to find these details I'd be MOST grateful.







JeromeMason

Re: Need info on Telefunken Pre
« Reply #1 on: May 27, 2015, 03:24:01 AM »
No one?? I'd really LOVE to at least get a lead on where to start digging. So far, I've come up empty on web searches for the part #'s and such. I figured there might be some telefunken junkies on here that might know where I could dig around.

Thanks guys!

Jeremy.Starseed

    Currently Sweden, oftentimes San Francisco
  • Posts: 91
Re: Need info on Telefunken Pre
« Reply #2 on: June 17, 2015, 06:52:16 AM »
Wow, that's one unique piece. I've never seen one before. It does indeed look like something from a portable console, and there might not be many left around.

Widening your scope and also scour the internet for tape machines from the late 50's in search for info on this thing, might turn something up...as it looks similar to certain aufnameverstaerker (recording amp) from some 50's or early 60's tape machines, but not one I'm familiar with. Perhaps that'll turn up something. I could be wrong. The tip off were the trim pots for bass and treble...but then there's that fader and mikrofoneverstaerker reference. Perhaps some kind of reporter mini-console for segments meant to be taped and edited before broadcast.

Best of luck finding pinouts. 
Mothership Mastering

" You won't believe how good you sound! "

Matt Nolan

Re: Need info on Telefunken Pre
« Reply #3 on: June 17, 2015, 09:57:37 AM »
I'm no expert, but don't those film caps (both sorts there), and the PCB date this as more recent than the 50s?

Two transistors (unless they're NuVistors??) and what looks like a small transformer. Variable pre-amp  gain, followed by EQ followed by output fader. Pretty compact!

Can you trace the connector pins to figure out the i/o ? Ground, balanced in, single ended (or balanced?) out, positive rail, negative rail. What voltage though?

JeromeMason

Re: Need info on Telefunken Pre
« Reply #4 on: June 17, 2015, 04:38:43 PM »
I can try to trace the pins, I didn't want to pull it apart if I didn't have to. I was hoping someone that might have some old siemens schematic libraries might be able to find this and shed some light. It's certainly unique, I'm dying to hear it, suppose I can start probing around. I'd just like to know what it is, and what it's from, I love the history of Telefunken, it always seems like that companies products tell a story of some kind.

Re: Need info on Telefunken Pre
« Reply #5 on: June 17, 2015, 06:31:19 PM »
Hi, this mic preamp could be from a stationary puplic address system, as you can find it in civic halls, churches or congress centers. It is clearly not from the 50s or 60s, the components and the pcb look like from the 70s or even early eighties. Telefunken and Siemens are not the same company or brand.   ;)

JeromeMason

Re: Need info on Telefunken Pre
« Reply #6 on: June 17, 2015, 06:35:45 PM »
I'm pretty sure it's late 70's 80's no doubt. The cans are opamps, ML709CT. So, not Nuvistors.

Matt Nolan

Re: Need info on Telefunken Pre
« Reply #7 on: June 17, 2015, 06:59:34 PM »
I'm pretty sure it's late 70's 80's no doubt. The cans are opamps, ML709CT. So, not Nuvistors.
Ah, of course. That makes a lot more sense.

JeromeMason

Re: Need info on Telefunken Pre
« Reply #8 on: June 17, 2015, 10:12:41 PM »
I'm no expert, but don't those film caps (both sorts there), and the PCB date this as more recent than the 50s?

Two transistors (unless they're NuVistors??) and what looks like a small transformer. Variable pre-amp  gain, followed by EQ followed by output fader. Pretty compact!

Can you trace the connector pins to figure out the i/o ? Ground, balanced in, single ended (or balanced?) out, positive rail, negative rail. What voltage though?

Well now that I know they're opamps it makes it a little easier to trace things down, before it was sort of hit/miss. I would imagine these hum around 18v, I'd probably run 15v at first and then see what it's gain is. I really wish I could find a pinout or schematic for this little fella, I'm sure it sound pretty cool, and I'd hate to make an assumption and pop the caps, everything is original and looks in really good shape too, doesn't look like it got much use at all to me. Hopefully someone will come along and stumble upon this thread that might know what she is, at least a model # of the console it was pulled from.

JeromeMason

Re: Need info on Telefunken Pre New
« Reply #9 on: June 18, 2015, 12:14:33 AM »
Well after taking some info from you fellas, I was able to track down where this module came from. It from a rack/box mixer and indeed for PA reasons. These modules were used in more than just this one unit though, there are some full out mixing consoles with them being used, mostly for broadcast and film, but hopefully this will lead me closer to finding a schematic of the preamp module and then I can get it wired up and see how it sounds. I would imagine it won't be any frills, probably just a very clean and nice preamp to use for something like hi hats or something, but still, such a cool little piece and there are definitely not many in existence from what I can tell, it seems these consoles are mostly located to Germany and haven't made their way across the big pond to the states. I will probably build a little wooden box to rack it in and have it on top of my console. Just now need to find the pinout. I'll surely let all that participated here know she sounds and update the thread, thanks for responses, it truly did help me trace it down.

Here's the link to where the schematics are, unfortunately I don't have an account to download them or to even see what the pinout for this is. If anyone does, I would greatly appreciate any help you could give,

http://www.radiomuseum.org/r/siemens_variodyn_vollverstaerker_v781d_bestnrc72392_a700.html?language_id=2

« Last Edit: June 18, 2015, 12:26:48 AM by JeromeMason »