My (quick and dirty) solution to humming issue

  • ![alt text](0_1609625365823_Spark_battery power.jpg image url)

    Me too had the hum issue. Before I managed to sign up to this forum and read other solutions, I came up with my own:

    2 x 12V 1. 9Ah lead acid batteries in series; dropped the voltage from ~25V to ~20V with 7 x 1N4001 in series (this is the quickest and dirtiest part of the solution; actually you'd want a proper linear regulator set to 19V with at least 3A output capability and maybe heatsink etc.). However, the hum is gone :)

  • @markus-melander Or you can save the time/effort/money and just buy a grounded replacement computer power supply that already has the proper voltage/amps for around $20US. I'm sure similar things can be purchased in other countries for not much money, too.