Neumann Module W544

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Oct 18, 2023
Hello everyone,
some time ago I bought a Neumann W444stb to make a preamp for my Telefunken M15 which has no input or output adjustments and this module was simple and clear to use.
Then since it doesn't have any VU meter I bought two W544s which have a nice LED scale thinking to use those but not finding the diagram anywhere they remained there waiting.
Thanks to you I finally found the diagram but the problem has become even bigger.
Now I ask you, what chance do I have of being able to use it as a preamplifier with VUs operating outside the desk for which it was designed? The power supplies are not a problem but the LED scale seems to take signals from outside, which is not easy for me to understand if perhaps by making bridges between the two connectors it is possible to make it work.
There's a lot of stuff inside those modules but the minimum that works would be enough for me
Many Thanks


  • Neumann W544.pdf
    1.6 MB · Views: 1

Not sure to get everything right, but this 544 seem to be a VCA fader with a lot going on around
The analog section is simple, but drived with a lin fader followed by probably a log amp to convert/scale the lin fader to audio log ramp while the vca is math log ?
The fader value also seem to be AD converted to 8bit (parallel bus), for grouping and master/slave operation.
Those 8 bit bus also driving the led bar to show the -real- value of the VCA gain/attenuation (the fader position can be different with a VCA group...)

I also suspect that in a console configuration a computer interface between fader/VCA section and led feedback, computer which probably handle clock and data routing for all digital side bus/master/slave/group...

Moding this 32 led ramp to act as a Vu meter seem way too complicated...

All subject to caution, this is rough interpretation...


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