V672 versions...how to recognize them?

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moqtev

Well-known member
Joined
Dec 30, 2004
Messages
53
Location
Aarhus, Denmark
...I'm doing some research on the Telefunken V672's. There is two versions (as far as i know) named V672/1 and V672/2...does anybody know about this or how to tell them apart?

regards

Morten
 
Hi Morten,

I might be wrong but I think it has to do with the transformers... V672/1 only has one output trano and V672/2 has 2. The boards are the same I think other than that.

I have a V672D, which is a dual, ie 2 pre-amps in one module V672, but they are 2 x V672/1 as they only have 1 output trano for each channel, though on the board there is the option and footprint for an additional trano, which would make it a V672/2

Hope that makes sense.

Cheers

Matt
 
Hey Butta,

I think they sound great. The have a bump in the mids that sound API?ish,
but a bit more mellow. They sound great on guitars and on vox and I?m sure
they would sound lively on a snare, not had a chance to try them on drums yet.

I have the ANT/Tele models and from my understanding the ANT models were
made after the original Teles (Tele became ANT). The original teles sound
?better? (not sure what qualifies them as better) from what I have been
told, though having spoken to Ollie from Tab/Telefunken he says the
ANT/Teles still make great pres for the money.

You just got to watch the lytics, from experience and from other board
members experience the old ones tend to short out the PS rail, I had to
recap one of them that was DOA, but replaced the caps and it up in good
health again.

The only other thing is that these, along with many other German Pres don?t
like 48V zapping the input trannie so you need to use a slow ramp 48V supply
for the safest way of operation a mic that requires 48V.

Cheers

Matt
 
I just got service manuals for V672/1 and V672/2. The V672/1 manual includes a schemo. I already sent a PM to Kubi so he can include them in his collection.

[edit] Kubi uploaded them already; go to http://www.kubarth.de/cgi-bin/diy/german/index,
the file names are:

V672-1
V672-2

You'll see that at least the V672/1 includes an opamp. It's labelled Mic709. For all I know that's a very old pre 741 design also known as LM709 or UA709. I don't know why they used such an old design. Other non-discrete vintage German broadcast modules used TDA1034 aka NE5534.

I don't have any V672 modules, so I can't comment on sound differences etc.
 
Another V672 question:

In the V672-1 schematic (the pdf at http://www.kubarth.de, direct linking does not work), does all the gain come from the preamp stage + input transformer? The output stage seems to be a unity gain opamp buffered with a class B output stage inside the NFB loop,according to simulation, does this look right? Are the output transformers step-up? 66dB (wired as mic preamp) from transformer + two transistors and a emitter follower looks like a lot, but i only have basic understanding of SS electronics...

TIA,
;Matthias
 
Here is a slightly gimped schematic of the output stage:

v672output5uw.png
 
discrete, IC, opamp, thin fiIm, SMD,

I'm still a bit confused reading this  8) : http://www.vintagetools.de/Vintage-Modules/Preamps/ANT-V672a.html

and here's the schematic , do I see an IC or not ?  :
 

Attachments

  • V672D.pdf
    1.5 MB · Views: 16

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