[BUILD] MP99 mic pre Thread

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sammy

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Joined
May 14, 2016
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Hello this is a Thread  for build help MP-99 microphone mic pre by General Audio Research
Microphone  preamplifier inspired by superior performance jensen 990 opamp & john hardy schematic

Features


    -GAIN +50db  very clean &  distortionless
    -Électronique solid state mic pre
    -Lundahl  in & out transformer superior performance
    -990 DAO  superior sonic performance
    -high-performance discrete op-amps laid out directly on the main circuit board.
    -Elimination of all coupling capacitors from the signal path
    -Easy to build
    -Easy to upgrade : tone , pad , Tpad volume
      +/-24VDC requirements

Build guide :


Step 1 : mp99 pcb


image.jpg

Step 2 : place resistors on pcb 

R: 10k
R: 200r
R: 6k8
R: 3k92

image.jpg


Step 3 : place condensator

C: 100pf
C: 680pf
C: 1000uF

image.jpg

Step 4 : AOP 2520 compatible

this preamp are specialy selectioned for AOP 990 (run with +24 & -24 vdc )


sk99.jpg

Step 5 : Transformer and OPA mounting on pcb

mp99 use  high-performance lundhall transformer
1:2 ratio input ll1527
1:1 ratio output 1517


image.jpg

this preamp Gives the possibility of adding multiples option if you are motivated  ;)
- pad
- switch polarity
- output 600 t pad

i recommande output psu symetrical
this preamp are sensitive with transformer radiation .

sam.




 

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