Ever see one of these?

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mrclunk

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Nov 29, 2006
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1,128
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London
Nope but looks very cool.
Outside broadcast mixer.
Germanium transistors?

I picked up a similar box recently.
Marconi OB mixer.
 

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pucho812

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Oct 4, 2004
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13,169
Location
third stone from the sun
The EMI runs on 12 x D cells or mains in the studion.
Early Plessey silicon transistors with 2N3054 complimentary output pais for headphone output.
Circa 1965, Australia.
No schematics anywhere but not complicated to work on.
a client picked one up. he thinks it's wired to run 50Ω mics and needs it for 150Ω mics. I haven't had it on the bench yet so can't say what is what. thanks for the info.
 

Jon S

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Joined
May 3, 2022
Messages
68
Location
Jurrasic Coast, Great Britain.
a client picked one up. he thinks it's wired to run 50Ω mics and needs it for 150Ω mics. I haven't had it on the bench yet so can't say what is what. thanks for the info.
They have input transformers and the usual impedance back in the day was 50 Ohms. I can't remember if there is a tapping for 150 Ohms or not. If not, replacement transformers are avaolable but mostly set at 600 Ohms.
Running them as they are should work but may alter the responses. Worth a try before spending a small fortune on it. 😆
 
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