Aguilar DB359 trouble shooting. Hi guys, just brought my new 359 home today and I am floored by the sound, however I think it may have some tube issues. I am using the DI out only at the moment but when I crank the master gain I start hearing an audible buzzing noise from within the unit itself, is this a bad tube? Also the power light will not light up. Scary thing is when I turned it on it blinked the power in my apartment despite being plugged into a Furman Voltage Regulator.