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converting a line output for a mic input

tedstruk

Jan 7, 2012
476
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Jan 7, 2012
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I have camera with an input for a 200ohm stereo microphone. I tried to split the signal with an RCA jack adapter, but the line input signal buzzed pretty erratic!
I wondered if there was a way to build a converter, or adapter, that I could connect my stereo mixer line out into the camera? The mixer requires an amp, the camera is a PK-958. It is a monster! with title charater, preamp.. the enchalada! I have the service manual, and can share any data you might need for this model, it has schematics, block diagrams and deflection and process diagrams. I can send a scan on the adio schematics if that would help?
thanks!
 

tedstruk

Jan 7, 2012
476
Joined
Jan 7, 2012
Messages
476
I also have another camera, an old Magnavox TV camera, that makes a whine that sharpens before shutting off in an audible snap, that I think needs a power cap changed in the viewfinder? Maybe someone can lead me through this procedure? heh heh!!!
 

tedstruk

Jan 7, 2012
476
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Jan 7, 2012
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476
Schematic for the audio board

The board has the stereo inputs as two mic inputs. There is also a mini plug in the case for a stereo mic. I have a stereo mic for this plug, I also have a mini plug adapter to RCA Composite. I don't care which jacks I use, What I want to do is build a converter, or adapter from line output in rca to input in the mic jacks.:D
 

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  • AudioCircuit2.JPG
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Resqueline

Jul 31, 2009
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You may get away with making a simple resistor divider circuit. If you get hum & noise using that then you'll need to use transformers too.
A mic' signal is only a 100'th or so of a line signal so you want to dampen the line signal about that much, but not more than absolutely neccessary.
So you may want to try using 47kΩ or even 22kΩ instead of the 220kΩ resistors. If it doesn't overlad the mic' input then this will ensure the least amount of hiss.
 

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  • Mic Adapter.GIF
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