I have an AC to 18v DC, 25MA, power supply (wall wart) that is used for a guitar flanger pedal. The supply generates some ripple noise into the pedal's audio (it is not there when using batteries). The supply has a transformer, two diodes, and a 1000uf 25v capacitor. I changed the cap, but the hum is still there. The diodes seem OK. Would changing the cap to 2200uf help or should I try something else? Thank you.
Electrical – Removing ripple in DC supply
dcripple
Related Topic
- Electronic – Is it possible to power an AC-to-DC switching adapter with a DC input
- Electronic – Ripple in the power supply
- Electrical – Effect of power supply ripple on ADC readings
- Electronic – DC voltage ripple help
- Electronic – Capacitor multiplier does not remove ripple
- Electronic – DC ripple stabilizer. 3rd order low pass filter. How to supply op-amps properly
Best Answer
In your job the current is low and the DC voltage does not have to be at all accurate .Batteries themselves however do not make ripple which means that the ripple rejection of your preamp may be poor .Single ended discrete component circuits can have poor ripple rejection but they sound good .So keep the adapter and the preamp and place some RC filtering in the DC rail between the adapter and the preamp .You could start with say 47ohms and 2200microfarad 25V.This will reduce the power supply hum much better than capacitance alone.