Ian of Jealous Creatures found a loose tube rolling around inside his amp. The Unbrokenstring Crew to the rescue!
We need to take a closer look (and find some Guitar Porn along the way!) Off comes the partial rear cover.
The smaller tubes, all 12AX7s are held in with spring-loaded bayonet tube shields. There is no hardware whatsoever to keep the tubes larger tubes in their sockets. Houston, We Have A Problem!
While we’re at it, Ian wanted us to take a look at the RCA sockets that handle the pedal duties.
Now that I’m getting older, I tend to forget where I found things, like cables. So I labelled them “I” and “O” to correspond to “REVERB INPUT” and “REVERB OUTPUT.”
I need the tubes out so that I can add retainer clamps to the sockets.
Let’s remove the chassis and take a tour of this fine amp. This is the chassis under the rectifier and output tubes.
Everything is wired point-to-point. Here’s the phase splitter and the end of the preamp tube string.
Here is the beginning of the preamp tube string.
Here is the front-panel pilot light.
A brass grounding strip is affixed behind the front panel controls.
These are the controls for the vibrato. Note the black ground wire wound around the cable bundle.
We see the VIBRATO input jacks in the center of this picture.
Volume and tone controls are here. This brass grounding strip is in the best shape I’ve ever seen compared to other units of this same approximate age.
Here we see the volume control and the NORMAL input jacks.
The power cord, accessory power socket, and ground lift switch. This is probably a replacement power cord because it uses the international color code scheme. American color codes are black/white/green.
From left to right, we see the fuse holder, power switches and the output/speaker jacks.
RCA jacks for pedals and reverb tank connections.
And this, ladies and gentlemen, is the end of our chassis tour. Back to work!
Ian said that the pedals were intermittent. The connectors were not broken, but I removed them anyway to scrub them down with contact cleaner. Here, a cotton Q-tip has been resized to scrub the bore of the RCA jack.
The same technique was used to apply a thin coating of Blue Shower protectant and lubricant inside and out.
The sockets were unscrewed and new tube base clips were installed. These are from the same OEM as supplies Fender and Peavey. Dunno why they weren’t installed in the first place… maybe CBS was cutting costs?
The RCA and its washer stack goes back home where it belongs.
After tightening the nuts, we’re soldering everything back the way it was.
This should wrap up everything electrical that has to do with the rear panel.
I hit the RCA jacks assigned to the reverb tank using the same process as I used on the pedal RCA jacks.
All the quarter-inch jacks were cleaned and lubricated.
The front panel jacks received the same attention, using the cleaner and lubricant process.
More input jack love.
This is a little better view of what’s actually happening during the cleaning cycle. Note all the gunk on the Q-tip.
This beautiful Fender-branded 5U4G rectifier is the first tube to slip into the tube base clips.
Your turn. This is a Ruby-branded tube.
This is a JJ/Tesla tube. We’re ready for final test.
Wow, this thing is loud!
Thanks for reading all the way to the bottom. With all the Guitar Porn, this is the longest post yet. I hope you enjoyed reading today’s post as much as I enjoyed working on this unit and documenting this little trip down Amplifier Avenue!
David Latchaw EE