Wow the eminence sounds great on it

A hard-rubber (soft-plastic) dead-blow mallet filled with lead shot is a great tool for applying a little persuasion or an "attitude adjustment" to a bent flange or sheet-metal chassis. Every tool-chest needs one !

I just picked up a basically new BJr IV. The newest versions from late 2019 have the new very different Bias Circuit. Sounded OK but that Brit Cap took some paint off the wall. Anyway.... I tore into it. First replaced the Cup Capacitor from .0022 to .022. The new circuitry replaced the .0022 to .022 in the last stage. Then I changed the Marshall tone stack (.022/.022) to the classic Fender tone stack (.1/.047...Twin). Then shorted out the Mid control ctlr ctr cx to left cx. And to top it off I took out the .100pf paint scraper brite cap and put in a .047pf cap on a switch. What a wonderful difference!!!! Now a small Twin with good bass, working Treble and Mid control with a brit switch that just adds more Fender sparkle. I would have never been able to do this without your videos. You gotta hold your mouth right to get that PCB (black) out. And the solder they are using is hard to vacate. Would be easy to burn some lift if not very careful. Thanks!!

I have installed a MM output tranny and choke on a couple of those and it made an appreciable difference. But the best tone I got from one of them was when I plugged the speaker into a 5E3 cab with a Weber 50 watt Blue Dog. It was an amazing sound.

Agree with your sonic perspective.. The ET65 seems to have that little bit of midrange notch that works really well through that cab.

The neo speakers are known for cutting the lows. I like the Celestion cream back or the Alnico Gold speaker in that amp.

i had to replace my tube board this week in my blues jr!! checked for cracked solder joint, which it had on all but 6 solder joints. i was going to just reflow them but when i did the pads lifted right off!! so new board and good leaded solder and shes sounding good as ever! would you recommend not using the stock output tube retainer? and just for back story it has a full bill m kit with adjustable bias.

I got one from a friend and one fire up that’s what it did! One power tube exploded damaging the amp. Fried chicken in parts of the board. A friend rebuilt the poor diodes and replaced all the caps with high quality ones as the factory grey caps are poor quality. Now it’s back and sounding awesome!

Listening to an ES 335 through this BJ I think it would have been interesting to contrast it with a Tele or Strat - with my BJ III (an Eminence Swamp Thang having replaced the Fender stock speaker) I have significantly more low end with an ES 335 than with a Tele or Strat. So changing guitars will require adjusting (at least) the Bass settings. Though I haven't yet modified the R51 to cool the bias (which I will eventually thanks to you repeatedly pointing this out) I'm somewhat surprised to see that so far (after about 10 years!) there seem to be no visible traces yet of too hot output tubes causing trouble to the PC boards or the tube sockets soldering points. But maybe that's depending on how heavily these amps are being run (or driven) after all. Also I actually feel that I haven't been forced to get new EL 84s too often in the past. Nonetheless it seems reasonable to cool the bias, anyway, as I admittedly do feel the the heat at the back at the amp when I turn it off after 1-2 hours of weekly rehearsal with the band... ADDENDUM: I did take off the back off the amp again today to take one more closer look and I noticed that there IS indeed a distinct discoloration of the orange print on the right hand EL 84 output tube, which suggests that it is actually running too hot - like you said it would! I'll have to look at this soon and add that 82K resistor piggybacking R51 to cool the bias... So thanks again for making me aware of this fact! Also - having the amp at home - noticed some tube rattle with V1 so I guess I have to rplace that one, too...

Here's an amp that actually needs a standby switch and doesn't have one. Lol Fender, you put a standby switch in shiploads of amps that should not have one and then on the odd amp that does actually need one you don't bother omg lol. My MkIV series 2 blew a tube within weeks and fried the board. Good job Fender, you also know they run too hot and still haven't fixed the problem even after having another attempt in the MkIV series 2.

Noticed when checking speaker screw tightness on Fender DR, that there is a substance like fingernail polish on each screw...? Is this a warranty trick...? Couldn't believe how many loose screws/nuts there were...!!! Thanks for that video that pointed out these things😉😎👍 😎👍

Quick question - the issue with the tubes running hot - isn't that what gives them the overdriven breakup? So if that's "fixed" then they won't growl? If the answer is "that is correct" I almost feel like I'd rather go through the tubes faster in order to get that sound. My volume lives between 10 and 12, using the Fat as a solo boost and oh lord I love the sound. If fixing the bias undoes that -- it's kind of taking away the golden egg that makes this amp sing? Happy to find out if I'm wrong.

Lyle, I'm perplexed - every amp I've ever owned has the speaker mounted to the baffle with 4 screws, yet the basket has 8 holes. Do the speaker manufacturers intend their products to be mounted with 8 screws? if not then why are there 4 extra holes in the speaker? The only reason I can think for the extra holes is to allow more flexibility in positioning the wire connection tab. What do you think?

We always called it Foot Pounds. My brother did auto mech for many years before aviation. Too many head gaskets.

I’m no expert but the new speaker in its current setup isn’t my favorite. In the name of science it will be interesting how it sounds with the amp wrapped up. Anyway always enjoy your approach.

I’d like to bring you my 90’s Fender ToneMaster head for service. Basically needs caps, etc….

I have a Blues Junior Mark IV... what resistor value should I use to "fix" the bias? The same value as the Mark III? Love your videos by the way. Thanks!

8:05 - who doesn't love a bit of "full wrist"?

So would a evm speaker be not ideal in an amp like this? They’re rated crazy high, aren’t they?

You didn't mention speaker break in. I know that makes a ton of difference. Also, what do you think of putting a 125 watt speaker in a 18 watt amp? Will it have the ump to get the speaker loosened up?

The Jensen C12N is the best speaker for a Fender Blues Junior

Are the threaded fasteners for holding the speaker to the baffle board actual T-nuts with the flanges inbetween the front of the baffle and the speaker cloth?? If they are, kudos to Fender for doing it that way. But, if the inserts are merely threaded into the particle board baffle, then 😖😖😖 #@%&!! .....and regardless I would prefer to see 8 bolts rather than just 4 (even for a lightweight Neo-mag speaker, but especially if the speaker has a large heavy magnet). Not to mention that Torx-head bolts would be easier to use than Philips heads, easier to remove and reinstall/tighten without slipping or stripping.

The Texas Heat was my favorite in the Blues Jr. and came highly recommended at the time I owned one. It had way more bass than the Neo demonstrated here. I wonder if the owner purchased it by mistake or something.

foot lbs on the drill

I use JIS bits and screwdrivers instead of Philips. This reduces the inherent mangling that the Philips standard is designed with...

Question: Is swapping the speaker on a Marshall DSL20CR something that a layman can safely do or would I need to get a tech to do it?

Hi Lyle. What speaker would you recommend for the B Jr? I have similar amp with a seventy 80. Crapola.

What's another good speaker for the Jr.?

EL84 amps are pigs on tubes .I have owned at least an half dozen el84 amps all at a same time & all of them had the original el84's fail & had to be replaced within one year .

That's the problem choosing a new replacement speaker there's no place to demo different speakers.

? I have the Monoprice/Harley Benton State Right 15w amp. It is cool biased, but the gain is extremely sensitive and goes very gainy after increasing the gain nob to 2, it's like the master volume. Because at 1, and you turn the amp up with the volume, it is pretty low in volume, but nice and clean. Once you get it to 2, you are already in crunch. How can I affordablely lower that gain and clean it up going past 2? Oh. It has the original speaker. The Celestion Seventy 80 12in.