Wayne, There's a time to take the amp to a pro shop andf get it done right. It' saves time and headaches, and also keeps you from inadvertantly smoking other parts or yourself. Now is that time.
SOURCE: Fender Hor Rod deville footswitch
If the footswitch is not switching correctly, open it up and check for any shorts or a defective switch. Sounds like it's a problem with the switch.
SOURCE: Fender Concert II preamp is faint and distorted on 2 channel
It sounds like a job for a technician. There are high voltages in the chasis and the potential for a serious shock to the unwary.
That said, I can suggest several possibilities.
First, make sure the controls aren't causing the problem. Contacts can build up dirt and oxides and block the signal. Try twiddling the controls and see if the problem comes and goes, or if you hear scratchy noises. If symptoms are found, buy a contact cleaner spray, take out the chasis after unplugging and letting it set for an hour, being very careful not to touch any exposed conductors inside. You'll see some holes in the control bodies; squirt cleaner for 2-5 seconds and work the controls.
Also see if the problem happens without the footswitch, and try the channel switches several times - same problem, dirt and oxidation.
Other possibilities - cathode bypass capacitors drying up, and it looks like the amp uses some opto-couplers at various stages.
SOURCE: Fender Hot Rod Deluxe Footswitch
Main thing to verify is that the particular footswitch and cable you have is specifically for that amp. If it is not the right one, that is your problem as there is very little compatibility among footswitches.
Looking at the schematic, plugging in JUST the cable shifts operation as you observed. This uses a crazy circuit in which AC is applied on the cable and the footswitch has a diode each direction that causes the amp to shift between the states. when you plug a bare cable in, it disconnects the internal diodes and switches for control at the amp, hence the signals float.
You should investigate the footswitch to make sure it is the right type with the diodes resistors and caps that is for the Fender Deluxe.
You can find the schematic for the amp here:
http://www.fender.com/support/amp_schematics/pdfs/Hot_Rod_Deluxe_Schematic.pdf
Look at the circuitry of the switches on the schematic at C8. Your pedal should have similar circuitry. Assuming your cable is good, the problem would be in the pedal itself.
SOURCE: on low volume using the
try a differrent speaker of suitable wattage and ohmage (displayed with a number next to a ? symbol on the back of the speaker),
or
remove the original amp speaker and gently push in and out on it, checking for uneven resistance or scratching. the speaker should retract and return smoothly, without any scratchiness or uneven resistance from within, and if there is any of this scratchiness or uneven resistance from within, the speaker is likely damaged from too much wattage or distortion.
168 views
Usually answered in minutes!
×