Bench tool · 1 of 2

RC Filter Corner Frequency

Whether you’re filtering screen node supplies or tweaking preamp decoupling stages, knowing your cutoff frequency (fc) keeps ghost notes at bay and your supply dead quiet.

Low-pass
— Hz CORNER FREQUENCY

Calculated using fc = 1 / (2πRC)

Time constant (τ = RC)

—

Bench tool · 2 of 2

Power Supply Ripple Attenuation

Pumping B+ through a decoupling node drops ripple voltage drastically at higher frequencies — see how much hum reduction you’re getting before it hits your preamp stages.

RC node

Output ripple

— mV

Attenuation

— dB

Enter filter specs above to calculate ripple reduction.

Attenuation is calculated from the RC low-pass reactance at the ripple frequency: Xc = 1 / (2πfC), then Vout = Vin × Xc / √(R² + Xc²). This assumes an ideal capacitor with no ESR — real electrolytics fall a bit short of this at higher ripple frequencies. Cascading a second RC stage after this one multiplies the attenuation ratios (their dB figures simply add).