Home › Forums › GuitarPCB Build Support › Ratt Build: (Moved to Support) This topic contains 3 replies, has 3 voices, and was last updated by Cybercow 5 months, 2 weeks ago. Viewing 4 posts - 1 through 4 (of 4 total) Author Posts December 29, 2018 at 5:27 pm #3594 BarryKeymaster I moved this thread manually to the Support section: Hi there – new to the forum – just built a ratt. Everythings fine on battery, (isolated) power supply (9V) creates a ground hum. Is there a troubleshoot somewhere on your site? Cheers Achim achim wollscheid December 29, 2018 at 5:34 pm #3597 BarryKeymaster Hi and welcome: This is the support section. I moved it for you. See the Photo from the Forum Home Page below: 2. If the pedal works fine when using a battery this automatically rules out the the Main Circuit of problems. I would check the wiring on the JACKs. I cannot help further from the photo provided. Check your wiring closely with the photo below which is the same for all builds: December 30, 2018 at 12:18 am #3612 wilkie1Moderator I see you have the build mounted in a plexiglass enclosure. That has no shielding from RF or other outside interference. If a transformer is nearby, that could leak hum into your circuit. Just guessing here. December 30, 2018 at 11:28 pm #3627 CybercowModerator Are BOTH input and output jacks grounded? Check ALL grounding. Any clear close-up shots of the guts? (Solder & component sides?) And as Wilkie pointed out, a non-conductive enclosure exposes the circuit to outside EM forces. Author Posts Viewing 4 posts - 1 through 4 (of 4 total) You must be logged in to reply to this topic.