[MrFixr55]

It's funny how switchers can wreak such havoc but they are the power supply for so much modern electronics, especially audio and sensitive instrumentation amplifiers.

I have 2 very cheap 120V power sources that put out a "modified sine wave" (stacked square wave) output. I tried to run an AA5 set on it to no avail, the noise even with the volume control was horrid. Tried an AC only transformer powered AM set with a full wave rectifier, and the results were much better, with minimal hash

After an issue with 2 ChiKrap 14.4V batteries that I used in my field audio mixer and wireless mic rig to power the 2 wireless mic receivers dying in the middle of a religious service, I decided to use the 20V Dewalt batteries for the wireless mic receivers. Since the receivers are supposed to run on 12-15V, I used a DC-DC convertor that was designed for cars to put out 13.8V with an input from between 8 and 30V. This would allow me to use either the 2 decent 14.4 V batteries or 2 of the 20 V Batteries. The batteries go to diodes to act as a block that if one battery dies or shorts, that it does not drain the other battery. Despite the fact that the DC-DC inverter is essentially a switcher, its output is clean and NO interference to the audio system is noted. However, I have not placed an AM radio next to it.