Redd 47 voltage gain ad 6 Step

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mahoule

Member
Joined
Sep 6, 2004
Messages
20
Hello!
I am currently building a redd 47 preamp and I wonder what resistance added for a variable gain as in the EMI model! be 22,28,34,40,46,52 db 6 step.
thank you !
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Because the way the REDD 47 is designed, it is very difficult to ensure it will be stable with gains less than 34dB. Ironically, the more NFB you use (for lower gain) the more unstable it becomes.

Cheers

Ian
 
I am currently building a redd 47 preamp and I wonder what resistance added for a variable gain as in the EMI model! be 22,28,34,40,46,52 db 6 step.
 
I am currently building a redd 47 preamp and I wonder what resistance added for a variable gain as in the EMI model! be 22,28,34,40,46,52 db 6 step.
This is not as straightforward as you might think. Unfortunately, simply changing the feedback resistor can cause instability at lower gains. To maintain stability over a wide range of gains you need to also change the open loop gain as you change the closed loop gain. In other words, the REDD47 is not designed to work over a wide range of gains.

Cheers

Ian
 
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