Fender Blues JR. - Diagnosis and Repair

Рет қаралды 1,536

11 ай бұрын

I bought this Fender Blues Jr. at a yard sale. It had obviously suffered some catastrophic arcing in the power section, not uncommon for these... but all is not lost. If you love the sound of your Blues Jr., you'll be glad to know that most are repairable. In this video I go through many of the documented failure points of this amp and get it running, add some protection from the design shortcomings and sounding great again.

Пікірлер: 16

@LarsonGuitarPlayer 9 ай бұрын

I would gladly buy this amp knowing it won't fail on me for a long time.

@valleywoodstudio7345 5 ай бұрын

I was given a dead BJ III for free - dead mains transformer and output transformer and a clear burn on the cicuit board for the EL84s - so I got an aftermarket one (much heftier!) alongside replacement transformers. In the UK they are all wired up for EU 230V from the factory when they should be connected up to 240V - the connections are there inside! Considering mains outlets can legally pump up to 256 V you can see how these things could cook. Aside from the bias mod this is an added thing UK peeps should be aware of! Mines running fine now and I like it - only mod has been to implement a switch across the bright cap. Would like to try either the Celestion A or WGS 65 as a speaker swap.

@rlarsen4562 8 ай бұрын

Sounds great.

@John_Galimore 10 ай бұрын

Nice fix. Yeah everybody dogs the construction. But it is a decent sounding little amp. The layout is certainly not as bad as a Mesa. If I ever find a decent amp tech in Eastern North Carolina I'm going to have them firm up the common fail points on my IV. Thanks for the video.

@OhmicronIndustries 10 ай бұрын

Thanks for checking it out. I think adding a variable bias on these can protect against common power section failures... but if you have the money, I would advise replacing the pcb that holds the tubes. They've been known to cause fireworks in the back of the amp occasionally :)

@thorynziemba2813 11 ай бұрын

This guy is a genius!

@tomterrif8503 9 ай бұрын

Clipping one leg of C3 makes the amp sound 100x better. It is another ridiculous Fender flaw, basically a bright switch that's on all the time. Just did it to my amp, and it makes a huge difference.

@OhmicronIndustries 9 ай бұрын

Good info...if I have another one of these come across my bench (which seems pretty likely😅) I will give it a try.

@rlarsen4562 8 ай бұрын

What about for the #1 USA model considered darker sounding than the later models ?

@jaysorensenIBEW 9 ай бұрын

Your video production was good, dude. You did some things I haven't done to my greenboard version. I just did the Fromel mod, CRex, MM OPT, bias set, but not potted. Etc. Right on 🤙

@OhmicronIndustries 9 ай бұрын

Appreciate you checking it out and thanks for the kind words.

@rlarsen4562 8 ай бұрын

Has Fender ever commented on the years of design and parts quality reviews like this one ?

@OhmicronIndustries 8 ай бұрын

Well I think there have been some modest improvements over the years, although many are purely cosmetic and they've failed to address the biggest problem which is that the factory bias is disastrously hot. At the end of the day it's a price point amp and I think Fender is probably satisfied with the lifespan of them. There's a planned obsolescence quotient at play I suspect.

@user-qm7nw7vd5s 8 ай бұрын

Circuit board mounted tube sockets is a nonstarter. Straight to the trash bin! I would have kept the speaker, and maybe the cabinet (if it’s not particle board). Where was it made?

@OhmicronIndustries 8 ай бұрын

These versions are made in Mexico. Since the tubes mount to a separate PCB, it's not difficult to remove it and just wire up sockets if one is so inclined. Like most production models, there are corners cut to save $ but a lot of people really like the way these sound and I had zero problems selling it.