Neuman V476B Preamp PCBs

[juliusbusch]

Hi guys,
I currently designed the pcb for the V476B Preamp by Neumann and just received the delivery from my manufacture. Now I got 10 pcbs, but I only need three or four of them.  Does anyone want some? I'll ship them from Germany. How about 10€ apiece?

 

[jensenmann]

Hi Julius
What transformers are the PCBs designed for?
cheers
Jens

 

[Zebra_PD]

I'll take two!

Send me a PM with your PayPal info and shipping cost

 

[[silent:arts]]

Georg Neumann 90471 and 90468, i guess. You could also use every other 1:1 ratio.

Sorry, but neither the 90471 nor the 90468 are 1:1
Did you modify the circuit for 1:1 transformers?

 

[jensenmann]

According to the V476B datasheet output 1 (transformer out) is 7dB higher than output 2 which omits the tranny. 7dB equals a ratio of 1:2,23 (stepup).
It´s not so easy for the input transformer.... That´s why I´m asking. I though you know more than I do.

 

[[silent:arts]]

A Friend of mine told me that they usually are 1:1 ratios.

Look at the V476 schematic, and the data sheet.
The unbalanced output 2 is 7dB lower than the transformer balanced output 1.
This can't be a 1:1 transformer.
(Jens was faster)

The input is 0,5 + 0,5 : 3 btw.

What do you know about this topic?

Those transformers in the photo you posted are mine.