Tube DIY Asylum

All you need at the grid is R3

76.90.100.230

This Post Has Been Edited by the Author

In Reply to: RE: strange phono stage posted by horny on August 25, 2024 at 11:37:15

C9 only needs to be big enough for the high pass filter's -3db point to be 2Hz (if you want 20Hz untouched by the filter). So the value necessary will depend on the input impedance of whatever you are driving with that preamp.

If that load is 100K then .8uf will do.

Tre'
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"Still Working the Problem"

https://www.digikey.com/en/resources/conversion-calculators/ (Open in New Window)

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