Fender Blues Jr. – The Fargen Hot Mod

By Russ Loeffler

I bought my Fender Blues Jr. in late 2001 because I wanted a compact, portable amp for casual jam sessions. The Blues Jr. I purchased has a blonde Tolex covering and it appears to be a “transitional” version of the amp. During this period, some were USA made amps with green circuit boards and some were Mexican made amps with cream colored circuit boards that began production in 2001. The serial number for my amp is post 2001 dating, but it is American made with the green circuit board amp. It does have the purported warmer tone of the green board version.

I was impressed from the very beginning with the quality, volume, and tone from this little amp. Although my go to for playing is high wattage boutique amps, I have always enjoyed this amp. I replaced the stock Fender speaker with a Celestion Vintage 30 speaker about three years ago and found it was a huge improvement... I fell in love with this amp again. With the new speaker I stopped using the “fat” button and I enjoyed the clarity, warmer tone, and additional head room that came with the speaker upgrade. 

Last year at the NAMM show, I saw a little red Blues Jr. keep showing up at different venues. It was being used for lap steel guitar and also a pop/rock guitar performances. The amp sounded great in a large club without being mic’d. After some investigating, I ended up at the Fargen booth and learned that the amp had been upgraded with the “Fargen Hot Mod”. I also learned that Fargen Amplification is based in Sacramento, where I had just relocated. I snagged some business cards and left with a new project on my gear wish list. 

After a few emails, I ended up communicating directly with Ben Fargen. He was very responsive and even offered to drive across town to pick up my amp. Now, that is what I call great customer service! I declined his generous offer and was able to drop by his shop to deliver my Blues Jr.  

The Fargen hot mod includes a Mercury Magnetic transformer, plus select capacitors and resistors.It also includes the addition of a “presence” knob near the fat button. 

This hot mod is not cheap, but I still had the image and sound of the little red Blues Jr. from NAMM in my mind. I was considering the purchase of a 25W to 30W amp to fill the void between my Blues Jr. and my higher watt (and heavy) amps. If this worked out, it would eliminate the need for the next amp on my list.

When I picked up the amp, Ben told me that I brought him a great stock amp.He said the original, stock Fender Groove Tubes still sounded great and the speaker upgrade was what he would have recommended.I told him I had a full set of JJ tubes ready to load into the amp and was going to see if I could increase the amp’s headroom.He didn’t think I would need it.

When I brought the amp home, I was very impressed.I played it for about two hours with several guitars including Strat’s, Tele’s, Les Paul’s, a semi-hollow body, and an arch-top.The noisefloor of the amp was reduced significantly. At the same time, the increase in the head room of the amp was dramatic.  The amp was “singing”.I found myself turning the reverb down from its usual setting because I didn’t need to artificially fill the sound. The new presence knob is a great addition for additional tone shaping.  The amp reacted very well with the different guitars.It delivered the requisite spank for the Tele’s and produced bright to heavier tones with the Strat’s and Les Paul’s. It even proved to be a great jazz box with the semi-hollow body and arch-top guitars.    

I swapped out all of the tubes with JJ’s and was found only a slight improvement in sound.  However, the new tubes provided even more headroom. This is one loud amp! It was difficult to get an overdriven tone with colder JJ power tubes even at high volumes. I tried different combinations of tubes and found that the amp sounds great with every combination. It just comes down to a matter of preference, with the neutral to warmer power tubes sounding better for my application of classic rock and blues tones.

The next test for the amp was to see how pedal friendly it was. The overdrive pedals included a Zen Drive, King of Tone, Golden Cello, a mod’ed Sparkle Drive, and Route 66. As expected, the amp works best with transparent sounding pedals. The loudness of the amp is even more impressive with overdriven tones. I also played through different reverb, delay, chorus, and tremelo pedals.The added clarity, presence, and head room of the amp reduced the compressed and tanky sounds that were present before the mod.

So, was this upgrade worth it?  For me, the answer is a resounding “Yes”. Not only does the Fargen Hot Mod make the Blues Jr. sound much better, the mod has filled the gap between the pre-mod Blues Jr. and my larger amps. The upgrade has moved this little amp over the line towards ”boutique”. The best part is that I got this without buying another amp.