Hi. I'm having fun building these "Ruby" practice amps from runoffgroove.com. I've wired it with a switching DC jack that cuts off the battery when I plug in a 9v wall transformer. The only problem is that the transformer introduces hum into the circuit. I've used shielded wire for all connections, and have even wrapped the circuit itself in copper foil tape with conductive adhesive (touching ground). I'm stumped as to what else I can do to get rid of the transformer hum. Any ideas?
Here is the circuit:
http://www.runoffgroove.com/ruby.html
And this writeup shows how the DC jack is wired in:
http://www.generalguitargadgets.com/pdf/ggg_ruby.pdf
Thanks for any advice you can offer,
-Scott
Here is the circuit:
http://www.runoffgroove.com/ruby.html
And this writeup shows how the DC jack is wired in:
http://www.generalguitargadgets.com/pdf/ggg_ruby.pdf
Thanks for any advice you can offer,
-Scott