put JJ tubes in my Blues Jr

D

DMyers77

New member
I recently ordered a retube kit from Eurotubes, and installed it my Blues Jr. This includes a balanced 12AX7 tube for the phase inverter position, and I specified moderate headroom for the power tubes.

I installed the tubes per their instructions, cleaning the sockets and all. When I powered up the amp and plugged in my strat, I was absolutely blown away at the difference.

I first got the amp 10+ years ago while working at a music store, as part of a Fender sales contest. When the amp arrived, I thought it sounded good, but not great. I occasionally used it to practice at home, but it mostly lived in my closet wearing the cover that it came with.

The tubes were original Groove Tubes, but I doubt I had more than 10 hours total playing time on them.

The amp now has more volume, breaks up easier when I dig in, has better harmonics, and has a chime that it never had before. Combined with the Belton reverb tank that replaced the broken original, this is a sweet sounding little amp!

Do tubes wear out from age, even if not being used? Or were the original Groove Tubes really that bad?
 
Re: put JJ tubes in my Blues Jr

I still think these are great little amps, and it's shocking that they're $500 now.

when I got mine several years ago, the consensus was to put in JJ power tubes, maybe a better preamp tube in V1, and a speaker change.

YES, those things made a big difference.

Even though JJs are probably still considered the best current production EL 84s, it's hard to say how much of a difference is due to the brand, and how much is due to the tubes' rating.
If you're happy with the new tone though, then who cares? :)

then play on
 
Re: put JJ tubes in my Blues Jr

Well, I think in most cases, the GT el84 IS the JJ rebranded, or it was for years, at least the over the counter ones where.
Not sure how closely matched they were when installed at the Fender factory, if at all.
In light of the fact that Fender now owns GT, I don't know.
I'd say, the pre-amp tubes played a bigger part in the difference, or maybe just the JJ's are better matched.
 
Re: put JJ tubes in my Blues Jr

Howdy,

Most likely your amp is biased for the rating your current output tubes have. I suggest you continue getting tubes from that same supplier. Good luck and enjoy!
 
Re: put JJ tubes in my Blues Jr

that's how everyone feels when replacing old tubes with new ones. They're louder cuz they're new. Hurray for new. That's what you're celebrating. Not the brand. The newness.

if you feel the same in a month, the tubes are probably good.

if you feel the same in 3 months, then congrats. You will have found some good tubes.
 
Re: put JJ tubes in my Blues Jr

When I got my pro junior it came with all sovteks which sounded awful for me the best combo were JJ el84's and tung sol 12ax7s
 
Re: put JJ tubes in my Blues Jr

Be aware, that modern el84 tubes don't last too long- esp if they are used in class A-type amps.
if you get a year of regular use, you are doin' good.
 
Re: put JJ tubes in my Blues Jr

marvar said:
Well, I think in most cases, the GT el84 IS the JJ rebranded, or it was for years, at least the over the counter ones where.
Not sure how closely matched they were when installed at the Fender factory, if at all.
In light of the fact that Fender now owns GT, I don't know.
I'd say, the pre-amp tubes played a bigger part in the difference, or maybe just the JJ's are better matched.
Click to expand...

Both the preamp and power amp tubes were Sovtek's with the Groove Tubes logo.
 
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