Fender Blues Junior and Pro Junior Bias Mod

 

Bias PotAdding a bias pot to the Fender Blues Junior and Pro Junior is becoming a very common modification these days. This modification helps extend tube life and reduces hiss in these amps. Another bonus is the amp runs cooler. The factory bias setting (which is set by a non-adjustable fixed resistor) allows the EL84 output tubes to draw too much current. With the addition of a bias pot you can adjust the bias properly for each set of tubes you install in your amp. Remember every set of output tubes will draw a different amount of current which is why you need to adjust the bias every time you replace them. I’m finding this is a very effective mod for these amps.

300Guitars Shop

My shop is located at 1 Executive Dr Unit L Toms River, NJ 08755 Please feel free to email me if you have any questions or are in need of some tech work.
  • Monday: 10am - 5pm
  • Tuesday: 10am - 5pm
  • Wednesday: Closed
  • Thursday: 10am - 5pm
  • Friday: 10am - 5pm
  • Saturday 10am - 2pm. (I am in every other Saturday).
I am also an Eminence, Mercury Magnetics, Mojo Musical Supply dealer. I do all the tech work myself so you deal directly with me. I am a one man shop and my hours can vary so please contact me to confirm that I will be open. Email me: billy@300guitars.com Call or text me: 848-218-0362 Shipping Info for all repair work: Please ship all repairs to: 1 Executive Dr Unit L Toms River, NJ 08755
I am currently offering all phases of guitar work which includes:
  • Set-ups
  • Fret dressing
  • Re-fretting
  • New hand cut custom bone nuts & saddles
  • Electronics work
And amplifier work which includes:
  • Basic maintenance
  • Bias adjustment
  • Repairs and restorations
  • Modifications
  • And more....
Testimonials:
David Nicholas - The 20watt amp is sounding fantastic! Delivered the goods at the gig and I'm finding cool tones all over the place with it. Love the cab w Emenince Tonkerlites too- perfect for my sounds! Makes the 12 string sound like a grand piano!
Peter Lacis - I had an audition for something recently that was all about Led Zeppelin I -- my custom Pennalizer BLEW THE MINDS of the guys I was playing with. They couldn't believe the sounds coming out of that amp. That album was never in my mind when I came up with the idea....so that's yet another testament to the amazing work that you do.
Scott Goldberg - I am very satisfied with the set-up, and the fast turn around.  With the "lower" action it feels easier to play.  I will definitely spread the word.