Fender Vibro Champ Recap

This Amp was given to me as a gift for doing some repair work. It's been great and you can hear what it sounds like by clicking here! Lately it's developed a lot of 60 cycle hum so I decided to change out the filter caps and swap out the cathode resistor bypass caps. This is an easy job and I bought the parts from Mojo (see picture of receipt below). They had a Vibro champ recap kit but it did not include the 10uF bypass cap so I just bought individual caps from their web site. I cut out the old electrolytic can and mounted the multisection cap from Mojo with two bolts, nuts and lock washers. To avoid enlarging the hole in the chassis I clipped off the 40uF cap tab and centered the other tabs in the existing hole favoring the ground tab near the side of the cutout for easy soldering to the chassis. I did notice that the 470 ohm cathode resistor on the 6V6 has opened up to 580 ohms and that someone had placed a 550 ohm resistor across the 1K resistor that feeds the second cap section. I left the 550 ohm resistor out but it looks like they also put an undersized resistor for the 1K , 1 watt resistor between the cap sections. More stuff to order later but I'll run it this way for now!

Schematic and parts layout in pdf format

Time to power on! No smoke.... no burning smell......... looking good. And.......... No Hum! Quieter than my new Fender Reissue Deluxe Reverb. I was so tempted to wire in the first stage filter cap as a 40uF like the silver face Champ but now I'm glad I didn't risk the extra inrush current through the tube rectifier.

Pictures! Click on them to see full sized pics.

Comments? email webmaster Greg