I'm having some very low hum in a tube preamp. I did some measures with RMAA and I see there's a high peak on very low frequencies... It goes from 15hz and goes high in 10hz.
Is there some simple high-pass filter I can build only for filter this low hum? A 20hz or even a 15hz hp filter would help. How can I do this?
Is there some simple high-pass filter I can build only for filter this low hum? A 20hz or even a 15hz hp filter would help. How can I do this?
What measurements did you make with RMAA? Can you post the measurement data and a schematic of the amp? Was the high peak at 10 Hz observed in a swept sine test?
What amplitude? I'd be looking at any layout or design problems first before trying to fix it with a filter. An RC filter might do you though, found with the 1/(6.28 x R x C ) formula or maybe a rumble filter?
Andy.
Andy.
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