The demand for small combo amps that can handle everything from home practice, studio work, and gigging is higher than ever.
Fender has two of the most popular amplifiers on their roster which were designed for this exact application, the Fender Blues Junior and Fender Pro Junior.
At first glance, these amplifiers look very similar and it can be tough to know which one is best suited for you.
But their subtle differences are important factors to consider when making your purchase.
Design

The Fender Pro Junior is quite a bit smaller and lighter than the Blues Junior. This is because it uses less glass and a smaller speaker, it ends up being just over 8.5 lbs lighter than the Blues Junior.
This might not sound like much but believe me, if you’re loading in and out of venues or traveling with your amp, that weight difference can make your life a whole lot easier.
Visually the Pro Junior embraces that old-school look with the classic 50s tweed finish and chicken head knobs.
This is the only finish it’s available in. So if you’re not the biggest fan of the tweed amp aesthetic, unfortunately you’re out of luck.
The Blues Junior on the other hand offers both the classic tweed finish as well as a black tolex finish which more modern players (myself included) will appreciate.
Although the Tweed version uses a Jensen C-12N speaker rather than the Celestion A-Type. Ultimately I found the differences between the two fairly inconsequential as I was able to get a tone I liked from both.
Controls
This is where these two amplifiers start to differentiate themselves from each other.
The Pro Junior is designed to be the epitome of simplicity. Sporting just 2 controls, volume, and tone.
This tone knob acts as a broad frequency sweep. It doesn’t help much with tonal sculpting if there is a very specific sound that you’re looking for.
Really what you are buying with this amp is the signature Pro Junior sound with the ability to roll off some low-end and accent the highs.
So when I wanted that specific sound it was ideal and incredibly quick to set up. But for anything else, I had to reach for the Blues Junior as there just wasn’t enough control over the sound.
The Blues Junior has a much wider array of controls to help sculpt your tone more effectively.
It uses the typical 3-band EQ setup with treble, bass, and middle tone controls, as well as volume, master, and reverb knobs.
Not only that, but it also comes with a footswitch. But this isn’t to change channel (it’s a 1 channel amp after all), it’s for an added feature Fender calls a fat boost.
This fat boost feature is wonderful. It focused the midrange and added some additional saturation which is very helpful when you just need a bit of extra juice for a lead or solo.
The Pro Junior by comparison has no such capability, so you’ll need to rely on some kind of external boost pedal to achieve a similar result.
Even though it has three times the amount of knobs, the Blues Junior is still very easy to set up and offers far more tonal variety.
Overall I found the Pro Junior too limited in its controls and didn’t live up to Fender’s claims of tonal diversity. Whereas the Blues Junior gave me everything I needed to dial in my sound without the need for external pedals.
Sound

Both of these amplifiers are intended for similar applications and are more than capable of handling them.
Whether you’re in the studio or on stage, both of these amps produce a bright and organic tone that has that special kind of warmth you only get from a tube amplifier.
So while I can’t foresee ever being disappointed with their sound, there are important specification differences between them that fundamentally influence the tonal qualities.
Let’s start with the speaker, the Blues Junior (tolex) uses a 12-inch Celestion A-type speaker whereas the Pro Junior uses a 1 x 10” Jensen P10R.
The larger speaker of the Blues Junior allows it to produce a little bit more low-end and thickness which I really noticed when playing those low-gain crunch tones and cleans.
The P10R still sounded great but was a little lacking in lower frequencies due to the smaller speaker and cabinet housing.
In terms of volume output, I found them both to be more than capable. Even at 15 watts, you can easily gig with either amp or play it at home without angering the neighbors.
You won't have any volume-related issues with either amp.
Now let’s talk about tubes. The Blues Junior is an all-tube amplifier, powered by 3 x 12XAC7’s in the preamp and 2 x EL84’s in the power amp.
That is a lot of glass for such a small amp! And you can really feel it too. The tones saturated wonderfully as I turned the gain up and I could feel it responding to how hard I was picking.
The Pro Junior is almost the same in the specification, but it uses 1 less pre-amp tube and introduces a solid-state rectifier which gives it a slightly more modern and punchy quality.
Overall I felt the solid-state rectifier was a good addition to the Pro Junior as due to its smaller stature it needed a little helping hand to push as hard as the Blues Junior.
Which Amp to Choose?

While these are certainly both great amplifiers that offer a no-fuss approach to getting a great, classic tube tone.
Ultimately I believe the Blues Junior is the better choice.
It’s certainly a little heavier, but the additional tone controls and larger speaker allow it to handle a wider variety of scenarios.
Yet it still remains simple enough to where even those who don’t want to spend time tone chasing can easily set this amplifier up in a few minutes and be ready to rock.
This does come at the expense of its size and weight. So if portability is an important factor for you the Pro Junior may be a better option.
Combo Powerhouses
When looking at amplifiers like these it’s important to remember the core philosophy behind their design and feature set.
It’s not to present you with tons of channels, in-built effects, or a complicated I/O suite.
These amps act as the core of a guitar rig that is there to produce the best-sounding organic tube tone in the simplest way possible.
How you choose to augment the sound from there using pedals is up to you.
Great comparison! I have a Blues Jr (western tolex version) and really love its sound. However, both amps have a distinct problem in that the output tubes are biased extremely hot, which burns them out quickly. The Pro Jr and Blues Jr should both be taken to an amp tech to cool off their bias before use. And just a small note – both amps are solid state rectified 🙂
Liam thanks for the comparison. I own a BJ tweed and I love it. I play classic rock, 60s and 70s mostly. Can you suggest an order of effects pedals that would work out best for me in this genre? Thanks much for your thoughts on this.