AC Adapter Hum Buster

[daren]

This is not exactly effects, other than it could be an add-on to one.

I was wondering if anyone has made an AC Adapter Hum Buster described in Craig Anderton's Do-It-Yourself Projects for Guitarists book.

My main concerns for this project are:
1. How well does this work?
2. Would it be alright if the capacitor's output voltage was more than double the voltage (He suggests a 12-volt capacitor for a 6-volt adaptor)?

[Dai H.]

if the voltage isn't regulated, the supply voltage can go up depending on the load (assuming non-regulated, heavier load = lower voltage, lighter load = higher voltage), also over time, the capacitor's ability to handle voltage can degrade with use if it's worked hard and filters heavy current, so using a higher rated cap can make sense. (Simple experiment, try measuring the output of an AC adaptor w/a load--i.e. hooked up to an effect or whatever--and w/out--i.e. not plugged into anything.) Also, you are talking about the capacitor's voltage *rating*, not voltage output. I have no idea about the hum buster thing.

[Paul Marossy]

The hum buster. That's where you add a 100 ohm resistor in series with one leg of the output of the wall wart and a big filter cap (1000uF?) across the output, correct? I've done that to several of my thrift store wall warts and it works great. Anderton suggests that the value of the cap should be at least double the expected operating voltage of your circuit. So, just to be extra conservative, if you have an unloaded output of 12V, use a 50V cap. The cost difference between a 16V, 25V or 50V cap is negligible.