We are back at it with another vintage Fender amplifier overhaul and repair!!
This one is part one of giving a total overhaul to a 1976 Fender Deluxe Reverb amp, including all new electrolytic capacitors for the filter, cathode bypass, and bias caps. New plate resistors as needed, new tubes, cleaning the pots, fixing the tremolo and reverb as needed as well as converting from the stock 1976 A1172 circuit to the classic AB763 circuit.
This first video includes an evaluation of the amplifier, removing the components of the power board (filter caps and power resistors) as well as a detailed discussion with schematics of the differences between the A1172 and AB763 circuits.
If you have one of these later Fender Deluxe Reverb amps and have wanted to convert it to the legendary AB763 circuit you will want to stick around for this one!
00:00 Intro
02:10 Back of the Chassis
02:58 Pulling the Chassis
03:35 Top of Chassis
05:49 Inside the Chassis
08:04 Power Supply Differences
10:12 Removing Old Filter Caps
26:23 Differences Between A1172 and AB763 Circuits
#amprepair
#guitaramp
#guitaramplifier
Great vid! 👍🏻
Love your videos! I noticed this issue only after installing a master volume but I’m guessing it was there before because I never turned the volume all the way until the master volume was installed.
I’ve got a JTM 50 that I built. Sounds amazing but there’s one issue that’s driving me crazy.. the bright channel pot cuts out the sound right at about 90%. Also goes dead when I put a jumper on the pot and bypass the resistor at 100%. so I don’t believe it’s the potentiometer. has anybody seen this issue before? I can’t find any leaking coupling capacitors bias voltage is good and the power supply voltage doesn’t drop when I lose sound..
Cool!