Nice comparison guys! REALLY appreciate the fact that that you not only set them the same, but then adjusted each to see what they can do with some tweaking.

"Less Fendery" is the exact word on the IV. Defiantly more body on the IV, almost "Marshally"...big sound. I like it. The speaker is defiantly making a big difference. GREAT comparison guys!

I definitely prefer the mark 4 clean. The 3 sounds more open and brighter for distortion. Overall, I like the mark 4 because it seems to keep that classic sound even with higher distortion. The 3 does sound good though for a brighter marshall gain sound and sounds a bit more like a metal type of tone but, the 4 has that classic cranked, full-bodied sound to it. The 3 also seems to break up a bit faster. Both awesome amps, I'm pretty sure that people could buy both and get use for each individual amp. Amazing demo!!!

That was a great fair comparison guys. Very educational. Thanks so much! I've got a Blue Jr III and am always bothered by its bell like high end. I always turn the bass up and reduce treble and reduce the tone knob on my Strat to try and make it fatter and bassier. Also I have the boost always on. I believe that the new one might solve many of my problems. Specially that I really love the Fender clean tones. I can tell a huge sound difference in headphones. Will go check one out.

You helped me to choose one. Thanks! Waiting for my IV.

Thanks so much for this comparison. It was just what I was looking for!Wonderful.

Great review! I don't own a BJr ... leaning towards the IV after seeing this as it better suits my needs. Thanks Gents!

Fantastic review. The review industry is over saturated (no pun intended), but there's definitely a vacuum (also no pun intended) when it comes to accurate comparison reviews like this. An exact A/B test was the right call.

I love my Blues Jr III LOVE it!! and the other day I was at Guitar Center and there was a white Blues Jr. with a Celestion speaker in it and I hated the sounds compared to mine; Now keep in mind I play a 79' Strat but I've found that there are lots of Limited Edition Blues Jr.'s with all sorts of different speakers in them. Bottom line is this I've tried all sorts of combo's but the eminence just seems to give me the best Hendrix tone which is what I like. There's a video where someone demo's a Blues Jr. III to a 59' Bassman combo and anyway yes one is clearly smaller but, it was just like his baby brother in sound. **Anyway what do I know I'm just a tone chaser!!**

I like the darker sound of the IV. Keeping my older blues junior but might not be my main amp anymore.

I've always hated the top end on the Mark 1, 2 and 3. I love the way it's rounded off on the Mark 4.

The best tonal comparison I've heard. And i agree with both you in your assessment. I just purchased the blues jr mark iv

Good review fellas! Thanks, Ontario Canada.

Should’ve done a test where you forgot about what the knobs say and tried to set exactly the same level and amount of drive and eq and taken reverb off

Great job guys. Thanks! I like the 3, but the 4 might prove easier to work with, especially with pedals.

I got the blus jr lv 2 months ago and switched out the speaker right away with a eminence taxes heat speaker and wow now I got that srv sound at a low volume! Love it then hit the tube screamer pedal for over drive ,nice.

The IV delivers a slightly scooped tone profile which I like better for high gain, but I like the III better for cleans and lighter break up. I can always cut down the mids. They will both take pedals well. I'll keep my two Blues Jr. IIIs which I run in stereo - they sound so awesome that way! Might be cool to run one of each in stereo though.

tried one today with a tele sounded fantastic for country rock and blues everyone should own one

If ya can't decide which one to buy just buy both and go stereo 😂😂🙌🙌🙌🙌

I would never have expected this huge difference.

The 3 seems to have more top end. The 4 seems "smoother" with more bottom. Also, it is true that the 3's reverb jumps out at you more ..... "washy" ? The 4's reverb is pulled back a bit and sounds almost HiFi. The overly "toppy" 3 really stands out with sc's. The 4's smoother nature compliments overdriven sounds. Overall, both sounds are good .... it just depends on what a player is looking for. I'm sure that EQ'ing the 3 can smooth out the top, and boosting the 4's treble can add top end. To me, it's obvious that Fender has re-voiced the 4 to "fit in" more with today's 'modern' sound, whereas the 3 really is more of a vintage sound. Solution: Buy BOTH and use a floor switcher :-)

Dammit, I was thinking about picking up a mk iii cheap and figured they'd be much the same. However, I much prefer the mk iv.

I much prefer the 4 over the 3. I had two 3's and sold both. Tried the 4 in Guitar Center and could tell a difference right away with the a fuller sound and less chime. Good video.

My blues 111 has a Jensen 12 inch C12N. My favorite speaker for a Fender sound. Its a keeper.

The BJ lacquer tweed was the best of them that I've heard. I have a III and a black face Princeton and they sound great together.

Great review thank you

If you turned the reverb up on the IV it would wind up sounding pretty close to the 3. Setting knobs to the same setting is not necessarily the best way to compare. It is a good starting point but the amps were designed to sound different, so it is fair to assume they would have different frequency response curves for the controls.

bought a mark 3 yesterday because this video!

I have a IV. Sounds great out of the box with minimal tweaking.

I'm glad I watdched this video. I like the III more than the IV by a mile. The reason why I want a Blues Junior in the first place is for that harsh top end. I love it

Great comparison! This is how it should be done! 10/10

This an excellent review. The differences are obvious.

Great tones, lads. That PRS is beautiful.

I am trying to pick between a III and IV right now and I feel the IV sounds better in every way esp the reverb. I have yet to compare them side by side tho

Great vid chaps , much better than those bell ends at Andertons!

It'd be nice to hear a comparison between Cannabis Rex, III and IV.

I know this is an older video but it's still relevant and some of these comments will be helpful to new buyers. I agree with Onix Junes comment that aiming the knobs the same way does not guarantee a match. Version 3 here was louder and much brighter making comparisons unequal. Best to use ears and try to match as close as possible - see if that's possible. Then see what the differences are.

The III sounds like a distorted small amp struggling at high volume. The IV sounds like a big amp that has the power to be loud without shite distortion.

I cannot pay attention to the sounds, that PRS is a beautiful guitar, haha, I love fenders but been latelly thinking on getting an SE Custom. Great demo , owned a BJ first generation and did some mods, I think it's one of the best, versatile and most affordable tube amps around, a big plus, wont break your back.

I wonder how much of the total difference is the Celestion speaker. I would love to hear the two different heads (Mark three verses mark four) played through the same cabinets and speakers to see if they truly improve the amp. As it stands I like the Mark three. Much better bloom.

Great comparison video. I think the clear winner it the Blues Jr. (leaning towards the IV).

I definitely prefer the clarity and high-end of the III.

When I was 10 years old played guitar with a very wise older guitar amp guru who revealed the secret 3 things for 100% best way to make ANY AMP sound better... 1:Practice 2:Practice 3:Practice

I have the original from the mid 2000s, replaced the Eminence with a Celestion Vintage30 a long time ago. Changed the tone completely. The boxy sound was gone. Also replaced the stock EL84 with the “blue” fender ones.

A good demo would be to see how much either of these amps can be tweaked to sound like the other amp using the given EQ, gain, and volume controls. I.e., I’m fairly certain they can be made to sound almost identical.

getting a fender blues jr III today!!!

I preferred the III for cleans (vintage) and the IV for distortion (modern). Since I buy an amp for it's cleans, it would be a III for me. Reminds me of the differences between the '65 and the '68 Princeton reissues.

I hear more tube sound in the III than the IV. The reverb is tamer on the IV! As far as the Bass difference I would imagine that could be adjusted in the bass control!

Really thought the range of both amps came through well in this video and the Mk iv is clearly the better amp for a single coil pickup clean or driven. For a gibson with humbuckers the mk iii sounded better clean but pretty thin when driven while the mk iv driven on both types of guitars sounded excellent. If you've got a gibson type guitar you'll want both amps, but if you've got a fender guitar you'll only want the mk iv.

I'm a bit late to the discussion but the reverb from 3 into the 4 is what I'd like. Or, maybe, a version 4 with a twin reverb--a Blues Jr. Twin Reverb for those of us that just love the 'verb.

they sound so good im gonna buy one

Lefty and a righty cool! Lefties rock! Nice strat man! Mark 3 is definitely brighter to my ear. I like the mark 3 myself. Rock on!

Sounds to me like the mic levels at the mic pre stage are quite different, which makes for a difficult A/B comparison. The three's mic input sounds more colored if not overdriven, and come across as louder.

I've got a Fender Blues Junior Lacquered Tweed NOS and it sounds great. May or may not replace the speaker. I have yet, to play out with it so, its difficult to tell the tone at higher volumes.. as I've only played in in-doors for practice. But, as it were---- sounds wonderful. Sounds lovely with my Fulltone Plimsoul pedal, as well. With both, single and double coils. Nice and portable.. looks really tweed-lacquer cool. Love the amp. The Jensen C12N sounds great, thus far. We shall see.

great video...I'll go for the 3

III more upper mids, less bottom. IV less mids, more bottom and cleaner all 'round. Sounds "nicer." III will cut through the mix better in live situation, but that IV does sound sweet.

Okay! Thank you, I but the Mark III and save me some money! For my beautiful 2 Les Paul Customs and PRS McCarty II.

Thanks for a great video! I prefer the IV, guessing much of that is because of the speaker. Sounds a bit more balanced to me.

I have the BJ III and is not a bad amp , but too much trebble sound.I changed the V1 preamp for a 5751 , and stock speaker( a Emminence Legend ) for a Celestion Creamback 65 , and now is much more balanced.Few amp of its range are best pedal-friendly

sounds like the 4 was a bit muffled but then to be fair it was using the same settings as used by the 3. A fairer way would of been to make independent EQ settings for each amp to show them off at their best for each style.

Band setting and two or more guitars, definetly no 3. It sounds both fuller and more bassy in person, I used one for rhytm guitar in my blues band, with the main guitarist on Strat driven Deluxe Reverb. Lovely amp with buckers, paired with a 339 or 335!

Great video, good to see a proper A B test not just dicking about.

Mark III is the typical fender twin flabby bass sound, nice to hear the IV has improved !

3 for sure people say it has too much reverb but I like it in my opinion well because of the time of music I play

Good comparison video. However, the difference in the spring reverb is so dramatic between the two, it would have been good to demo both amps without any reverb at all, so the reverb wouldn't colour the sound on the III so much.

What are the original amp settings in the video before you guys change anything? Love the tone!

The reverb is very noticably dialed back. I bought a new one yesterday after having a tweed one and I noticed right away the reverb sounded very dull

Really have an issue when you compare with the same settings. Set each up for the beat tone and then compare. One amp might sound like crap at current settings but might be better it set up appropriately.

The differences can mostly be compensated for with a graphic equaliser.

Has anyone tested the Mark 4 against the Blues Junior Lacquered Tweed? Can't decide which one I like more

they sound great with the PRS

Blues Junior III LTD laquer tweed for sure and by far. Jensen speakers - divinely sweet.

I like the Blues Jr. IV. So I will be getting that 1.

@3:00 Eminence speaker in the BJ III, Celestion speaker in the BJ IV.

It depends what application you need! For just cleans mark3 it’s better! If you want your blues jr to be like vintage and add pedals as distorted pedals you should get the eminence speaker GB128! Or if you have the tweed one just replace the Pre-Amp 12AX-7 stock for the electro Harmonics 12-AX-7 it will get the best of the both worlds with the Jensen stock speakers! That’s my experience with it

III has all that glassy character and reverb is as it should be. The IV's reverb is totally castrated. You can get all the lows you want out of a Blues Junior by swapping speakers or driving a nice 2x12. Feeling very good about my III right now.

The IV has way better string definition for chords

The clarity of the IV is so much better.

It's easier to add shimmer type reverb to the IV than it is to remove it from III. I have both amps. LOVE the 4 and I use a pedal when I want that glassy shimmer sound. And then kick it back off when I don't want it.,

it seems to me the mark 3 sits better in the recorded mix, but maybe live the mark 4 sounds bigger. not sure. I think the three sounds more alive, but im obviously judging only from the recording.

I'm shocked that I preferred the 4. Smoother & less ice-picky treble response. More dense / less drippy reverb - too.

great video, I really have been having this very question. thanks for postitng

I’ve never heard the word “interesting” so many times on a review before !!

Also the writing and labels for the knobs on the IV are facing the front of the speaker. The labels being upside down on my Blues Jr III has always been incredibly annoying.

Man, what a great morning.

The III is a bit cleaner . I’ve always maintained that a 15 watt amp with a 12” is best for solos with a natural sustain . You don’t have any headroom at 15 watts if you’re chording .

Today is my first day with fender blues jr 3... and to my ears it sound better than IV...

To bad the volume is louder on the older series?

Why go out and buy a mark 4, when u can adjust the tone settings on the mark 3 ?

great comparision,,

4 sounds more transparent and un colored where the 3 has more of a midrange range sound. I use a 3 for both 70-90’s rock and Southern Rock, takes pedals well too.

A iv it is for me then but is it available in lacquered tweed?

Different wood cabinets. Is der a weight difference?

that prs sounds awesome

Try the master higher and the preamp to taste....there is no wrong way to set an amp though. Cheers!

The Mark 3 sounds definitely more dirty with more presence in the sound than the mark 4 but the reverb sounds a little bit too loud on the third.

3 sounds way better and full bluesy which this amp was made for! Mark 3 my choice for sure!!

How would people compare the III to the older model, pre-2010?

Was in doubt with clean, go for the 4 when it clmes to distortion. Definitely. Also heard the holding of the use to break easily, so scared of this

Yeah the IV sounds too warm and dull? The III is bright, but does get pretty washed out and crunchy as you get louder. I still run an original 2006 version with the 60th sticker beautiful tone. I also have Reverb as well, but still mostly plug into Junior at home and it goes everywhere.