Hello PedalPCBer's! I just built the Cobalt drive and passthrough and LED works but zero sound when switched on. Nothing at all. Since I don't have an 9v AC power adaptor, I just wired in a 9v battery. Might be a dumb question but should a 9v battery be able to power the Cobalt just as well as a 9v AC adaptor? I have triple checked components and also checked for shorts / polarity. Stumped but thanks!