Fender Blues Junior - Common Problems & Solutions Pt1
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- čas přidán 5. 09. 2024
- This is one of the most common amps under the sun.
It's weaknesses are the same across all generations so far.
Here, we take this thing apart and go over them in the process.
Stay posted for the next episode where we address them and give it a test.
I ain't never had a problem with my Blues Junior. I think the smoke makes my gigs more atmospheric.
That's just like, an opinion man.
What's wrong with a bit of smoke for ambience, eh?
After all, that's what the punters go out looking for.
That and to get wasted.
Funny.
Fascinating video. I always wondered what makes a good vs bad PCB. Also not surprised to learn that there are so many Aussie euphemisms for fucked.
I remove the screws that hold the tube board in and take both boards out at once. It is much easier for me to have the boards on the bench and not bending the ribbon cables too much. Great video
The Canibus Rex is the STOCK speaker in this amp: The FSR Blues Junior with this particular Tolex and speaker Grille cloth covering. The Canibus Rex came from Fender with this speaker installed. Fender did other small “special runs” of Blues Juniors with different speakers, different Tolex and Grille cloth coverings, also as FSR amps.
I had no idea, thanks mate.
It's literally the only one I've ever seen or heard about.
Love your videos Brad
What you like is your choice. We all like a different sound when it comes to speakers.
Absolutely.
Another great video, Brad. Yes, I have worked on a cathode biased Blues Junior IV…and a fixed biased Blues Junior IV. I don’t think Fender can make up their mind.
I’m loving your replacement valve mount PCB. So much better than Fender’s. I’ll hit you up for one to keep on the shelf.
Deadset! Hit me up with some photos and any stories you'd like to tell if you have time, mate. I'm yet to see one.
It sounds just as hazy as I'd expect these days from Fender!
@@BradsGuitarGarage you bet. I’ll give you a call next week.
thanks for suggesting I take my amp to a tech before I burn it out dinking around thinking I know what I'm doing when I can't even understand half of what you're saying. But the take it to a tech part was nice and clear ;)
I don't want to discourage people from getting into it, however if you're not interested in making electronics a lifetime interest and you just want your amp to perform again quickly, for the long term, the cheapest and quickest alternative is definitely a tech.
Those look like nice sockets for hand tightening or loosening of pots and jacks, with the *knurled" grip (that's the word you were searching for). I have a set of double-ended Hozan sockets for this purpose, but ordinary deep sockets will work if you rough up the outer chrome with a Dremel for better grip, or put rough textured, non-slick heatshrink tubing on the socket. There are special plastic "Rocket Sockets" on the market but I've heard that they are kinda soft and wear out.
I think you should design up a replacement main board that turns that hotrod series truly great reliable and great sounding! There are hundredes of thousands of them things out there!
There are great people that already do that, let me look it up and get back to you.
Noooo!! Fix the Hot Rod series and the world’s Techs go broke 😂
I think more people looking at Blues Juniors, but on a budget, should consider the Laney VC15 or LC15R
Thanks! I had the speaker plugged into the footjack…….
Omg I just bought one and no sound is coming out of it and it’s popping loudly at random times! RETURNING FOR
Cool video, I’ve got a blues jr on the bench right now … fun ….. anyhow where could one go about getting the nice little pcb to add the trim pot onto the board , that’s a nice looking solution.
Cheers Bebop
Look up Keld Ampworks in the UK.
@@BradsGuitarGarage
Thx Brad :)
Interesting that that has a v rating of 240. In the Uk I've switched mine - a buster I'd been given for free to fix up - to 240 - it does have the tap available. Where we are in Leeds the mains can be up to about 250 easy.
Yes, in hindsight, I think this one was set up for an actual 240v but that is rare. This is probably why the plate voltage wasn't way off the high end on this particular specimen.
More often the international amps are sold as 240V input, but you look at the service manual and transformer specs (if available or printed on the transformer itself) and it actually says "220v" or "230v" input.
I'm going to pick up my blues junior today from repair but I am not happy with the price but it seems everything is fried.. Arc is probably the initial contribution to the end result of frying an amplifier that's never left my bedroom plus has never been above volume levels that would awake or bother my neighbors. Hence I'm in an apartment building so the levels have been low... However, according to this repair shop, the entire amplifier is shot.. been playing fender amplifiers my entire life. I'm 70 years old now and gigged for 30 years with fender apps.. what the hell happened to this company?
we also call them cable ties
Love the video Bradley! I'm commenting before I've watched part 2 so... Have you ever upgraded the O/T to possibly a !8watt style Marshall type? Maybe something with an 8K5(ish) input impedance?
Sorry for the late reply, mate! The budget has never allowed for OT replacement unless one had gone catastrophically wrong. However, that could be another avenue for improvement and experimentation, should someone have absolutely nothing better to do. Lol!
I switched my BJr. 3 on after a year not using it and the outer power tube (next to speaker out) flashes up white followed by a nice purple light show.and noise...switched it off and on again...there also was a strange smell in the air
after the white flash I could shortly hear my guitar for a few seconds before the noise started...in hope it's just a tube
While it was likely just a tube initially, the fact that you could smell something likely means that the amplifier has suffered significant damage. Time for a tech inspection, mate. If a new valve PCB is required, I manufacture and sell upgrade boards on my website www.bradsguitargarage.com.au
@@BradsGuitarGaragethanks man, it was most likely just a bad tube...Everything looks fine on the boards,no burnt spots/smell etc
I switched both tubes (outer "lightshow" tube to the inner slot) and the amp worked fine, but the bad tube didn't glow in the inner slot (the good did)...I will put in a new matched set...
HAPPY END: I put in an unmatched NOS EL84 (from a hughes&kettner amp) I had lying around and both tubes glow like christmas and the amp is dead silent and sounds good...I leave it on now for an hour and see if everything stays fine
Hey Brad what are the values you use on the C1 position please? ....something to 4.7 is what I heard couldn't make it out. I have a gibson hollow body. Do I want a lower or higher value? I'm finding it breaks up too early. Thanks man!
Aim somewhere from 0.47uf to 4.7uf according to taste. Higher values will have a lower frequency cutoff point.
Ok so higher values will break up earlier? Thanks Brad!
The values of C1 are not directly related to "breakup".
Read this: www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwirg4GP_ej9AhWw3jgGHV7MD5IQFnoECAoQAQ&url=http%3A%2F%2Fvalvewizard.co.uk%2FChoosingBypassCaps.pdf&usg=AOvVaw2c3w-37e_iAU7j1qswoEZM
And simpler graphical examples here: www.valvewizard.co.uk/OtherStuff.html
hi! i just have a problem with my Bls jr, pratically it turns on (so he got current) but it doesn't sound, what can be? thanks a lot
Could be a dozen or more reasons.
You need a technician.
Let me know where you are and I'll see if there's anyone nearby I know of.
Great video! Brad! I have the exact same amp. I decided to convert it to point to point wiring before the PCB had a chance to give me a problem. It also has an adjustible trimpot for biasing the tubes which were biased way to hot from the factory. One way for fender to sell more tubes and amp repairs 😁. At least now it's easy to troubleshoot and replace parts if necessary. The one thing I have try is changing the 47uf bypass capacitor on V1. You're right about it having way too much gain in the first pre-amp stage. The volume control is basically unuseable as is. You mentioned on your video you used certain values but I couldn't make out what they were. I've disconnected my 47uf capacitor and the gain gas dropped and the volume knob is more useable. There's just a tad bit too much base. What value do you usually use? Thanks.
I've gone as far as 0.47uf for that bypass cap with great results. It's starts to lean toward Marshallesque style distortion. Obviously the architecture is very different, I'm just talking about the EQ balance prior to the distorting stages.
@@BradsGuitarGarage Thanks for your reply Brad. Now that I've disconnected the 47uf cap the volume pot has a more useable sweep with breakup starting between 6-7. There's a bit more bass coming through however than I like. I was thinking maybe 2.2uf or 1 uf.
👍🏻👍🏻👍🏻
What’s a good alternative with 15watts that does cleans and break up ….not looking for an amp that does super high gain
AC15's are fantastic (once they're modded to not eat EL84's, anyway!), Orange do some good stuff too, around the same price range as the BJR.
Cool. Thanks. …rather not have to mod more than a speaker ….especially since I can’t mod myself it just raises the cost
Link for purchasing that PCB?
My Blues Junior crackles when the lead moves in the Jack. Then it goes really quiet. Anyone have an idea what the issue is? Would appreciate it
Likely a cracked solder joint, mate.
They can be replaced by hardwiring a more reliable switchcraft chassis mounted jack.
@@BradsGuitarGarage thanks a lot pal
Guitar amp manufacturers, stop setting bias so hot! I had to replace output tubes in my Marshall Origin 50 (less than 2 yrs old) because of hotter than needed bias.
Do you have any suggestions for Blues Jr Harp mods
From NJ USA
I don't know much about tuning to harmonica, but I've heard that generally unruly 5-ish watt single ended amps with with no neg feedback, 8" drivers, with limited bandwidth are preferred.
So I'd suggest perhaps lowering the first stage bypass cap to below 1uf, perhaps some different bypass and coupling cap values downstream, either playing with feedback values, or switching or completely disabling it.
Also, take into account what the mic output impedance is and modify the input stage to suit if required.
Could be a fun project.
Is it possible to buy your PCB for the valve sockets? Thanks
$50au ea + P/H. Flick me an email.
Comprehensive man
Where you based in aus ?
Emu Plains NSW, mate.
@@BradsGuitarGarage well I’ll know who to call if my blues junior cooks it
👍
Better not to use the crappy PCB…rebuild the amp with an old school Fender Style board or a turret boards and populate it with more better components than Fender’s barely adequate voltage ratings on the caps…in essence fix the problem to last 20 years, instead pushing it down five years to the next tech…
Zip ties, that's right....
'F' straps
I think I've heard Canadians call them "zap straps" too.
Tomato, tomato, potato, potato, eh.
Lot of money for a tube amp to have issues
Tell that to a Mesa owner!