I have a red DD-1. It has always worked perfect on all my personal builds. Yesterday I was having trouble with it while trying to set gains on my newest build. Head unit is an Alpine CDE 172BT and the amp is a CT Sounds 125.4 When setting the max head unit volume, it didn't get a signal until volume was at 24 of 35 and no distortion up to max volume 35...thought that was a little weird, but could be legit. Next when trying to set the amp, I kept getting hardly any signal, then the 40hz and 1khz would light up but the signal light would not. I tried several different tracks and could not get any consistent reading...if any readings at all. No speakers were connected and I tried all 4 channels. Occasionally all lights would light up for a couple seconds and then go off. I checked the 9 volt battery inside it and it tested good. Any idea what the problem could be? I ended up just setting gains half way and hooking up the speakers...all speakers were working fine and amp was loud and clear.