Neumann EQ transformers - modern replacements

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beatnik

Well-known member
Joined
Oct 18, 2009
Messages
1,179
Location
Italy
Hi everybody,

I have been accumulating a bunch of Neumann parts lately and I have a few original OA10 discrete opamps available.

I would really like to build a passive eq based on the PEV-c circuit. This eq is quite limited in features but should sound good.
I have the older version PEV-b which is fantastic, but a different beast, a lot of transformers and inductors. Would be too hard to copy.

The PEV-c circuit is quite simpler in terms of parts count, and the only  difficulty would be finding suitable input and output transformers.

I haven't been able to find any information on the 09355 and 09322, these are the Neumann part numbers for the ipt and opt respectively. There are probably corresponding Haufe part numbers but again no luck finding these.

Would be great if I could get some input in selecting an appropriate replacement. Lundahl parts catalog is quite big and hopefully there is something worth trying out ?

I don't know much about the theory behind audio transformers and would be great not just getting the correct replacements for the PEV-c but also to understand some general methods for selecting the correct transformers for a known circuit.
 
Looks pretty uncomplicated, I think?

I would try first with

input:
LL1540, wired 2:1 (-6dB for accommodating high'ish levels into 24V-rail processing)

output:
LL5402, wired 1:2 (+6dB gain to boost MOL over what's applicable on 24V-rail processing)

..but that's just a reflection of my taste in iron..

Jakob E.
 

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