siemens V272 pinout mods

[bob cheniot]

Hello all you out there,

I'm looking for some info on siemens V272 gain-control modifications.
On this forum I find quiet some information on modifying V672 modules with pinout instructions...
Can anybody tell me if they are the same for the V272? I figured out that V672 and V272 are more or less the same units but I wonder if the pinout info is the same and if I can make the same mod?

Thanks a lot,

a humble newbie

 

[RemcoV]

Hi Bob,

Welcome!

For the pinout take a look at Kubi's site. He's got a real nice collection of schematics and diagrams of vintage german modules on there.
V272 is in there aswell

http://www.kubarth.de/cgi-bin/diy/german/index

Groetjes,
Remco

 

[bob cheniot]

thanks remco,

but i'm not really a specialist in reading schematics....
i'm wondering if anyone knows the modifications for the v272 using just the pin-outs, I found a lot of info on the V672, but I wonder if the pin-outs are the same?

Thanks a lot,

Bob

 

[jensenmann]

The pinouts are the same. The Rundfunktechnik stuff was designed to be interchangeable.
:guinness:
Jens

 

[Rossi]

V272 and V672 are definetly not the same. They're actually not even similar, despite what you might have read on the TAB Funkenwerk pages.
The V672 has a 0 ohms input and is designed to be configured via external resistors (input inpedance + gain). The V272 is a 34 dB fixed gain "Aufholverstärker" input impedance is about 2 kOhms. The V272 has no pins for gain configuration.

 

[jensenmann]

:shock:
Thanks for correcting me. I better should have had a look on the schems since I repeated what I´ve been told without crosschecking.

 

[Rossi]

I actually bought a V272 based on information on the TAB Funkenwerk site, only to find out that it's their info on those modules is incorrect. Should have looked at the schemos myself! :roll: Although I'm not sure they were available online, back then. Kubi's ever expanding collection is really the best source of information on vintage German broadcast stuff.

 

[bob cheniot]

Thanks Jens and Rossi for the info,

did any of you already modyfied a V272 as preamp?
So I understand the only way of modding them is to open the case and modify it on the inside?

Bob

 

[echorec]

Hi Bob,

I use unmodified V272 amps as preamps. It works great if 34 dB is enough for you. If you need more gain, I recommend buying a Neumann W444 (or similar) active fader (cheap on German ebay) and connect it after the 272. Then you get appr 20 dB extra gain and it will run off the same 24 VDC that you use for the V272. The picture is the stereo version of the Neumann fader.

Good luck, it is a nice (pre)amp.