Dispelling the myths about MC phono cartridge loading

[andyr]

37 minutes ago, Warren Jones said:

Andy, you can measure Zin of the 1st gain stage. Just use a 1kHz tone and a variable resistor measure the voltage across the variable resistor and when it drops by 1/2 then the variable resistor will equal Zin of the 1st gain stage. This method is used in the Cal Lab to verify Zin on scopes etc.

 

Thanks, Warren.  

 

Although I suspect you would need to use a variable res that's able to go up to 500K, at least?

 

[Warren Jones]

54 minutes ago, andyr said:

 

Thanks, Warren.  

 

Although I suspect you would need to use a variable res that's able to go up to 500K, at least?

 

 

I suspect Zin will be meg ohms. We used switchable decade resistor boxes for the tests you could do something similar with regular metal film resistors your uncertainty will be a few % but it'll get you close enough.