Fender Hot Rod Deville 212 sounds ok then LOUD HUM
The problem is not the input cable/guitar cord. The problem is not the tubes, the problem is not the filter caps. The clean channel seems to be the culprit, normal white noise as there should be and then all of the sudden there is a loud hum even with all knobs turned all of the way down. the only way to stop the hum is to turn off the standby switch or pull the phase inverter tube. I have seen others post this condition before but have seen no answers. This has to be a common problem so there must be someone out there with the answer. A little help would be appreciated as Fender will not help because I am not an authorized warranty center. Even though there is no way that this amp is in warranty
Music - Fender - Musical Instruments Corporation Fender Hot Rod DeVille 212...
Answers & Comments
I don't recall coming across this problem. I would remove the first preamp tube. If the hum is still there then I would remove the second preamp tube. If the hum persists, its time to check out the cause with the help of the schematic, step by step. Best to send it in to a repair shop. I wish that I could help further.
On mine, the guitar input jacks get tarnished and causes all kind of interference and noise. Take a Q-Tip soaked with WD-40, run in down into the jack and brush up and down. Don't overlook the filter caps as they are a common cause of noise. You need a capacitor checker (the older tube type) to thourghly check those out.
I checked the caps with a Fluke multimeter and an ECG capacitance meter. Then I replaced the filter caps with Sprague Atoms. I brought the amp up slowly with the variac. The tubes were checked on my Sencore tube tester. The tubes tested good but I replaced them anyway because I have tubes in stock all of the time. New caps and new tubes. Nothing wrong with the old ones. Still has the VERY LOUD HUM. Fender will not let me talk to one of their techs. I will never endorse them again. The days of Leo are long gone. This is not a tube amp. This is a solid state amp with a few tubes in it. My customer thought he was buying a REAL Fender like a AB763 but after he saw whats inside this thing he wants to sell it. The problem is that it has to work first if he wants to get any money for it.