I hope to speak with Mark today, but I turned on my Regal, everything Lights up, fuse good, jewel indicator, all filaments in every tube, but no sound. I tried Replacing every tube from the rectifier, all preamp and power tubes, But still no sound. The speaker is functioning when connected it to a different amp. Changed guitar cords and guitars. I "might" be experiencing a slightly louder hum than usual. That's unfortuantely, the extent of my skill as a trouble shooter. I have a feeling it's something relatively simple. Amp worked fine the other night. Yesterday nothing. Any thoughts/ suggestions?