63 fender pro, fix or sell?

[dmartn149]

IT'S ALIVE! I took some measurements as described on the tube amp debugging page
Tube Amplifier Debugging Page and the PT was measuring okay. so I started looking around and found a couple of loose ground wires. so I soldered them back on, plugged it in and the tubes began to glow. I slid it back into the cab and hooked up the speaker and a guitar. So now it makes sound, not very loud, lots of hum and crackling, but it AMPLIFIES Now for some contact cleaning and re-tentioning.

[SoK66]

Don't push your luck, replace the filter, bias & bypass caps before you go much further.

[Steve Conner]

Yeah, it's quite possible that the only reason the fuse isn't blowing now is because the one you put in is too big.

[dmartn149]

Okay Steve, do you have ESP? the fuse from the Peavey is a 5a and the Fender wants a 3a. I figured it was better that the wad of foil that the previous owner had in there. Anyway, I'll get the correct fuse today, give all the pots & plugs a good cleaning. and then see if it still works.
I know I have a lot to learn about amps, but I do know about draining caps, lethal voltages, etc

[Jag]

You have an amp that WILL work.

Don't push your luck, replace the filter, bias & bypass caps before you go much further.

Heed those words before you "see if it still works".

[loudthud]

More words of advise: Measure the distance between the bolts that hold the power transformer and compare to any replacement you plan on buying. It's a giant pain if the replacement isn't an exact fit.

[dmartn149]

Okay, now it has the correct fuse, and all the pots, sockets and jacks are clean. It sounds pretty good, except for a crackling/sizzling sound that seems to be associated with vibration. It is only there when playing low notes, and the lower the note, the more crackling I get. Gently bopping the side of the cab causes the same crackling, while tapping the tubes does not. Also If I am going the change the filter caps, are those the two on the rectifier board, and are there more in the filter pack? Yes I am a "noob"

[SoK66]

No, those are the bias caps, which should be replaced along with the bypass caps on the component board. The filter caps are underneath inside the cap pan.

Be VERY certain to drain any residual voltage from the caps before messing around with them. They can store potentially lethal voltages, at a minimum can knock the crap out of you if you're not careful. To drain them of any voltage, with the amp unplugged run an insulated jumper lead from pin one of any preamp tub to ground, then turn both the power and standby switches to the "ON" position. This drains any voltage from all of the caps safely. Check at the standby switch with your VOM and you'll see the voltage steadily dropping.

[dmartn149]

Thanks SoK66. I have been draining each cap, one at a time, through my VOM. I hit both ends of ea. cap and the leads from the cap pan, then do it again to be sure.
I'm pretty stoked that it is working as good as it is. The crackle went away when I bolted it into the cab.
When I tried to remove the cap pan, it felt like it was glued on. Are there hidden screws? or is there something else going on?

[Bruce / Mission Amps]

Thanks SoK66. I have been draining each cap, one at a time, through my VOM. I hit both ends of ea. cap and the leads from the cap pan, then do it again to be sure.
I'm pretty stoked that it is working as good as it is. The crackle went away when I bolted it into the cab.
When I tried to remove the cap pan, it felt like it was glued on. Are there hidden screws? or is there something else going on?

It has a foam strip vibration thing glued in under the lid that sometimes gets stuck the filter caps... unless there is something going on that I can't think of, just pry it off.

[dmartn149]

Thanks Bruce, that's exactly what it was, pretty scary getting it off, it was really stuck. So basically I need to replace all the electrolytics, right? And they are the ones that look like cardboard tubes? All the blue molded caps can stay, right? Also, my schematic shows 600v filter caps, but the caps in the amp are 525v Do I need to get 600 or 525 ?

[Bruce / Mission Amps]

Thanks Bruce, that's exactly what it was, pretty scary getting it off, it was really stuck. So basically I need to replace all the electrolytics, right? And they are the ones that look like cardboard tubes? All the blue molded caps can stay, right? Also, my schematic shows 600v filter caps, but the caps in the amp are 525v Do I need to get 600 or 525 ?

Yeah, leave the blue tone and coupling caps alone for now... they're pretty good right out of the box.
Yup those paper covered main filter caps are the original caps... it probably has the original old cathode bypass caps and bias supply cap too.
Regardless of what some body else might say, replace them all while you can.
I very seldom see over 485vdc on any of those old Fender amps so I'd use some decent 500v caps and leave it at that.

[dmartn149]

Thanks Bruce. I'm glad to find out that I can use the 500v caps as they cost about 1/2 as much as 600v caps.