Another item I should mention is if you plan on doing the full blown 1% resistor change for the mod, pay attention. Read Read Read the mod paperwork (BillD Mod). Not only did they change all them resistors, they changed some value too so you must know what the resistor change was. Just as an example, they changed the resistor to match the LED change on the front panel (the BillD has a blue LED and and needed a different voltage to work correctly). There were other value changes and that may change the way your C-1 will operate. Some people don't like the blue or the retina burning intensity of it so you can play with the value. I have the changed value resistors and reason written down in my C1 folder but if you have the mod directions, it's buried in there. This was another reason I didn't change out 150 resistors willy-nilly. Save the 150 changeout for a second session after you do the basics. See if your unit works by the book first.