Fender Blues Junior Modifications

Unleash the tone of your Blues JR with these modifications from Fromel Electronics!

From the factory, this pint size wonder has a lot of potential, but with some select Fromel tweaks this amp can stand toe-to-toe with some of the finest boutique amps on the market.  After the mod, the amp boasts clean, sparkling top end, a huge sweep of mids and rich bass response.  The smooth, slightly compressed tube breakup stays articulate thanks to improved power filtering and upgraded tone caps.  The reverb is also made more lush and rich, with smoother decay.

Additionally, the kit upgrades every tone-critical cap in the circuit with high quality F&T and Nichicon electrolytic caps.  All the capacitors in this kit were specially chosen for great tone, reliability, and accurate fit in your Blues Jr.

(The standby switch kit and Mod reverb tank not included in the Supreme Kit.)

Make sure to order the correct kit for your amp: If your amp was made in the USA order the "for USA" version, if it was made in Mexico order the "for MIM" version. The Recap kit is the same for either.

"Have us Install" price includes parts and labor. We will bill you return shipping upon installation completion and which will be comparable to the cost of shipping it in. You can view USPS Parcel Select shipping rates HERE . Since we're located in the Pacific Northwest you can calculate shipping cost by how many zones it crosses to reach us from where you ship it from.

Click here for info about sending your amp in for modification.

Included in the kit is all the components necessary to to get your amp in top shape and the detailed instructions to make the changes easy. If you have a basic understanding of electronics and soldering skills you can do these mods in a couple of hours. These are the upgrades we offer for the Blues Jr.:

Tone Stack - Replace the wimpy Bass and Mid caps with high quality WIMA caps with corrected values to open up the tone and get rid of that boxy sound. The leads on the caps are pre-formed to insure a perfect fit. What about the Treble cap, replace the ceramic cap with a high quality MLCC cap. The adjusted value shifts the mids up very slightly, the result is an amp that sounds huge and warm, not boxy and thin. 

Twin Mod - Fix the mids on the amp and get rid of that flabby bottom. This mod enables you to take all the mids out of the tone allowing more flexibility and versatility. This is accomplished with just a short jumper wire but the result is far better control of your tone.

Power Stiffening - Doubles the capacitance in the first filter stage, this reduces hum and increases reserve power for solid bass and strong picking, This mod gives the amp the extra torque it needs to push through strong when you are playing hard. In addition all the filter are replaced with F&T and the bypass caps are audio grade. 

Cooler Bias - You are cooking the output tubes in your amp. This mod lets the amp run cooler without sacrificing tone or drilling holes in your PCB. Your tubes should live a long and happy life after this mod. I include a new bias resistor that sets the idle on the tubes to about 8.5w which is right where it should be.

New Input Jack - Your input jack is soldered directly to the circuit board, apply some tension when the amp is plugged in and you could cause major damage to the circuit board in the amp. This mod gets rid of the wimpy plastic input jack and replaces it with a high quality jack, with its own board!.

Proper Lead Dress - Take a look inside a boutique tube amp and you will see all the wires carefully twisted and placed for greatest reduction in oscillation and noise. The Blues Jr has all the internal wires zip tied together. I give clear instructions on dressing the leads inside the amp for optimal performance, this results in lower noise and less chance for oscillation.

Reverb and Tone Mod -  for older Blues Jr's. The reverb on older Blues Jr's sounds horrible, this mod changes the reverb to the design of the newer Blues Jr's. If your Blues Jr was made before 2001 the reverb sounds pretty bad. This mod fixes that to produce that lush classic reverb tone that made Fender amps famous. In the oldest Blues Jr's (made before 1996) the tone is dark, the tone mod brightens up and adds more clean headroom to these first versions of the Blues Jr for a great improvement in tone.

Reverse "Sparkle Mod" - If you have a Blues Jr. III you'll have Fender's "sparkle mod". Some find the "sparkle mod" to be brittle and ice picky. This is a simple mod to reverse and we provide the component and instruction to do so with this kit. Reversing the "sparkle mod" will take your Blues Jr. III back to a series II Made in Mexico version Blues Jr.

Recap Kit:

Electrolytic Cap Upgrade - Replaces all of the power filter and cathode bypass caps with high quality F&T and Nichicon caps..  Older Blues Jr’s that are made in the USA are all getting due to have their filter caps replaced and many of the current Blues Juniors made in Mexico are known to have leaky filter caps.  The Fromel kit rectifies these issues.

Standby Switch Kit:

Swap out your power switch with a new one that has a middle, standby, position. This is a very easy to install kit that requires no soldering. (International amps not supported.)

Reverb Footswitch Mod Kit:

Our Reverb Footswitch Mod Kit converts your footswitch jack in the back of your amplifier controlling the on/off of the FAT circuit into a footswitch that controls the on/off of your reverb. The kit includes full color instructions on how to perform the mod as well as the necessary wire for the USA version and a new Fender brand footswitch.

Mod Reverb Tank:

Replace the weak reverb tank in your amp with a new Mod tank for richer, fatter reverb. The made in USA Blues Jr.s usually have Accutronics tanks that we think sound good, but if you have a Belton (or if you just don't like the Accutronics tank) this is a great upgrade.

WARNING: Performing these modifications WILL void the warranty on your amplifier. Working on amps can be deadly if you do not take proper precautions. Follow these instructions very carefully. If you are at all unsure of your ability to perform these modifications STOP and take your amp to a professional to be modified. You can also send your amp to me for modification.

No Warranty: This kit and the instructions included do not include any warranty of any kind. The modifications to your amplifier are at your own risk and you agree to completely hold harmless the seller of this kit against any and all claims. Tube amplifiers contain parts that operate at very high temperatures and deadly voltages. If you are not sure of your abilities to perform these modifications then do not perform them.

All orders are processed within three business days, however, international shipments may be delayed up to six weeks depending on customs.

Customer Feedback::

"Just installed my mods. Easy to follow instructions. Good God! It brought my amp back to life. The dang thing had just sizzled out a few days ago. A 20-year-old amp has new life. Thanks Fromel Electronics. You are the best." Lee - Blues Jr. USA

"Thank you!  I have to tell you after sitting here putting in some time just playing through various tones, I really appreciate what your mods have done. It’s definitely a quieter amp and the bottom end is so much more useful. The amp seems to have lost some of its boxiness too. And I am absolutely in love with the tone of my Strat through this, even more than my Blues Deluxe Reissue.
I find that the tone that inspires me the most is what I call just, ‘wires on wood’. This amp is pulling those two ideas right out of my hands. The warmth of the wood with the glossy highs (but not too harsh) of the strings. It’s just so damn natural and Earthy!
Thanks again for all of your help, I’m a very happy customer!" Mike P - Supreme mod & Tube Board