Getting a cleaner, louder Blues Junior

[papuanewjimmy]

First off, I'll preface this by saying this is my first tube amp, so I'm new to this whole game. I've been playing guitar for about 10 years (just turned 24), so yeah, I'm a late bloomer in the tube world. Its a lot easier to sell a goofball high school kid a 100w amp than a 15w amp when the pricetag is the same, regardless of the difference in sound!

Anyways, I recently realized the error in my ways, repented, renounced my solid state roots, washed in the water of the river- well, you get the idea... I bought a Fender Blues Junior. I'm SO unbelievably stoked. It sounds amazing. I have only one gripe- I'd like it to stay clean at higher volumes. I believe I'll soon be referring to this as "breaking up later" or "having more headroom"? I can't yet describe to you what the sound is that I'm going for, but right now I like the way it responds with the volume at about 2.5-3 and the master at about 6-9... just BARELY getting dirty when you pound a chord. What I'm going for is something like the guitar on Tom Waits' Mule Variations... think "House Where Nobody Lives" or "Come On Up to the House."

So from what I gather I can change the tubes and speakers easily, but what recommendations do you folks have in either or these categories, given my goals? I've heard changing the 12AX7s to 12AT7s helps? And what brand/wattage speaker should I be looking for? I realize I could just buy a higher wattage amp, but funds and space are limited, and I'm really happy with the Jr for the most part. I'm no idiot, but I have little to no experience with circuits and electronics, so I'm mildly wary of trying some of Bill Machrone's mods. Has anyone tried this one (not Bill's, but I found it through his site): http://home.comcast.net./~machrone/bjr/bjgunther.htm

Thanks so much,

Jimmy

[Don Moose]

Here's the thing, Jim - a loud clean requires more power. Distortion is what happens when your amp runs out watts before it runs out of gain.

Here's the sick thing - doubling the watts only gets you 3dB more loud, which is supposedly barely noticeable. Get a speaker that's 6dB more efficient and bingo, you've gone from the loud a 15W amp will make with the original speaker to the loud a 60W amp could do with that same original part.

A more efficient speaker would be your first step - more loud for the same watts. I don't get involved in questions of taste, though, so have no suggestions.

[bob p]

IMO the first thing to consider if you want a little amp to sound like a bigger amp is to play it through a bigger amp's speakers.

Little inexpensive amps invariably tend to have less expensive speakers that have a lower power handling capacity than big amps have. As a result the distorted sound from your little amp is likely the result of a combination of amplifier distortion and speaker distortion. Before considering any mods to the amp's electronics, I would consider trying out the amp with a clean sounding speaker that's capable of handling far more power than your amp is capable of delivering. In a case like that the amplifier will be giving you distortion, not the speaker. That may be all that you need.

That's a place to start, anyway.

[papuanewjimmy]

Thanks for the replies guys, that was just what I needed. Don, you certainly are wise- I hate seeing people argue over matters of pure taste!

So my question now is what specification are we speaking of when we say that one speaker is more efficient than another? Is it simply that one is rated for a higher wattage, or is there something else to take into account? Bob, when you say "far more," can you recommend a wattage range I should look into?

For others potentially interested in this topic, I didn't complete ALL of my homework before my initial post. While I had heard that exchanging tubes for different members of the same "tube family," I found this page of Bill's Blues Junior website immediately after posting. Sorry about that.

http://home.comcast.net./~machrone/bjr/bjtubes.htm

One more speaker question- aside from just buying speakers until I find one I like, are there places I can hear side-by-side comparisons of speakers played through the same amp? I'd also like to learn a little bit more about the differences between speakers, like what is the audible difference between AlNiCo and ceramic magnets (and why does (/doesn't?) it exist. I've only found an old Guitar Player magazine review of about a dozen speakers, and it wasn't all that helpful.

Thanks again for your input, Bob and Don. Like I said, that was exactly the sort of help I was looking for.

[bob p]

Speakers are the kind of thing that are very much a matter of personal taste. If you ask 1000 people for advice on what speaker would go well with your amp, you might get 1000 different answers.

The most common speakers used in guitar amps are probably Celestions, Eminence, and Jensen. Other good names to consider are Weber and Electro-Voice. You can find speaker specifications at each of the manufacturer's web sites and compare some numbers on-paper to get an idea about efficiency. I don't think you'll get much useful info about tone.

Within each line of speakers you'll find models that are prone to distort and models that are less prone to distort. As a rule of thumb higher power ratings suggest that the speaker will break-up later. Weber is the only manufacturer I know of who rates their speakers in terms of early/late break-up. If you want cleaner tone, that means later break-up.

For my purposes, I like to use a speaker that stays clean all of the time, and I like to get distortion out of my amplifier. I like to use EVM speakers rated at 200W to 400W for this reason, even with my little amps. They stay clean. Another valid approach is to get speaker distortion as part of your sound, but if you want a cleaner sounding amp that might not work for you.

If I were in your shoes I would disconnect the internal speaker in my BJ and hook up a bunch of different extension cabinets to see what sounds best. Don't expect a quick answer. Some people spend years searching for the right speaker and amp combination.

[Satamax]

Jymmy, the hard bit gonna be to find a more efficient speaker. The gold label and special design fender speakers are made by eminence. And they usualy make pretty efficient speakers. Efficiency is noted in DB I'd think the emmies in fenders are around 98/99db, that's just my guess! So if you want 6db more you'll have to go for 104/106db! That starting to be big!

Red thang, wizzard and so on for the high efficiency from eminence.

http://www.eminence.com/guitar.asp?speaker_size=12

You can check this on the celestion's site, thought there isn't a clear chart and you'll have to check each speaker individualy for efficiency rating.

http://professional.celestion.com/gu...tone/index.asp

I seem to remember that there was a 106db somewhere around, thought, i can't remember if it was celestion or jensen.

Jensen doesn't seem that efficient after all there's the chart.

http://www.jensenvintage.com/tonechart.pdf But again, you'll have to check each individual speaker for proper ratings.

Weber doesn't even lists efficiency!

http://www.tedweber.com/

[Shark_Sandwich]

No, Weber doesn't list efficiency, but give him a call or email and he'll give you good advice.

FWIW - I bought a Weber Blue Dog (Celestion Blue clone) about 6 months ago, and I love it. At Ted Weber's suggestion, I upped the size of the magnet (ceramic) in order to increase sensitivity. It is a much louder speaker than I was using. I think it's louder than a Celestion Vintage 30 that I tried out. I'm using a very old PA amplifier for guitar, probably running at 15-20W, and it's plenty loud enough to play medium sized bars with quite a bit of clean headroom.

Give Ted Weber a call or email - he knows his stuff, his speakers sound great, and they are relatively inexpensive.

[JJGross]

I was looking to get a better distortion sound out of my HRDx and found in my amp an 80s era Carvin 100w British Series speaker was the ticket. With a power tube swap from 6L6GCs to EL84s and old manufacture pres my clean is still Fender, but driven I'm leaning way into the Marshall/Vox realm than the fizzy stock Fender overdrive. The old Carvin British speaks can be found on ebay or CL around $35. You might not like the sound of them, but I'm not changing anything in my amp now.

For 'never break up' speakers you might want to check out some JBLs. I have a pair of them in my 70s Twin. Crystal clean at all levels, they just don't break up until you're hurting yourself. That's not making a joke with a 135w Silverface Twin Reverb loaded with a pair of JBLs.

Cheers,
- JJ

[bob p]

For 'never break up' speakers you might want to check out some JBLs. I have a pair of them in my 70s Twin. Crystal clean at all levels, they just don't break up until you're hurting yourself. That's not making a joke with a 135w Silverface Twin Reverb loaded with a pair of JBLs.

are you talking about "hurting yourself" when you play that amp loud, or when you try to lift it???

JBL "D" series speakers are GREAT for loud and clean, but they're pretty damned expensive pieces of vintage gear. Probably a LOT more money than one would want to spend for a Blues Junior extension cabinet. I think that Ted makes a Weber California that's small enough to fit into the BJ cabinet. That might be a reasonable solution, Jimmy.

[stokes]

All good advice on the speakers,just wanted to chime in with a vote of confidence for Ted Weber,he is one of the best.If you email him and tell him what you are looking for he will give some solid advice and recomendations,he has hit the nail on the head at least a half dozen times for me or others I was doing work for.I believe he can match any speaker out there.

[WholeToneMusic]

speakers

I have a Blues Jr. on the test bench that had a custom wood ring made for it to fit the Weber Sig 10 and it sounded good, I did the Bill M tone stack mod and this amp sounds dynamite. The Sig 12 may be worth looking into. I hear that it doesn't sound as good as the 10 though.

[WholeToneMusic]

Ruby Reverb tank

Also I forgot to mention that I changed out the Reverb tank to a Ruby, Just in doing that alone the amp sounded better.

When Fender designed that circuit they biased the tubes very hot and the amp is as loud as you want to get it without replacing EL84's every other day, What I would suggest is to increase the 22k bias divider resistor(R52 on the creme board) to 30k, The amp will run cooler and it sounds cleaner, better for Jazz However it will have less power.

I have tried this with a customers amp and he was very happy with it. This allows you to use other EL84 tubes that normally wouldn't hold up with the way the amp was originally biased. Your best bet is to try a higher dB speaker which was recommended earlier in the thread. Another option is to get the Mojo Blues Jr Output transformer upgrade which is more efficient than the original and have it put in, It also sounds better than the original transformer. Check the Bill M mod page to get more ideas for your Blues Jr.

[ctcpete]

I have a 2003 Blues Junior with the original Jensen speaker and just finished the following Bill M mods about a week ago: Basic kit, cream board Presence control,High-voltage preamp mod, Switchcraft all-metal Input Jack, clean boost module, and power supply stiffening. If you are not comfortable with soldering and electro mechanical work, you may want to have these mods done by a tech. I was a field engineer in the printing industry for many years so I was comfortable doing them. I am now trying a refurb and blackface conversion on my 74 Silverface Twin Reverb.
I do have a problem after doing the Blues Junior mods with a hum that occurs at higher volumes with my single coil pickup G&L guitar (not evident with a humbucker equipped guitar). I believe the mods added some extra gain. The hum was probably there all along but I didn't notice it before as I had been playing it at lower volumes. Any advise on controlling single coil hum on a Blues Junior? I have tried twisting the like color xformer wires together. Would the upgraded xformer help out maybe? I am waiting for a reply from Bill. I've heard he has a 6 month backlog of amps at this time. Other than the hum I'm very happy with the mods.

Pete

[ncboy654]

if you do all the mods ctcpete did, you can replace the 50k master volume with 100k or maybe 250k for a little more output, but as other people have said, there's only so much clean to get from a 15w amp.

[WholeToneMusic]

Hello Pete,

The mod makes it sound much more pleasant to the ear. The Blues Jr is very suseptible to outside interferance around the first gain stage. If you even wave your hand around v1 inside the chassis you will get noise. I would suspect that it would be a lead dress issue with the grid wires too close in proximity to other wires, and the 12ax7 just amplifies that even more. You could try using a 5751 preamp tube in V1 which has an amplification factor of 70 opposed to the 12AX7 which is 100. If that doesn't work you could try a 12AT7 which has an amplification factor of 60.

If you have the chassis open and are comfortable with working on a live amp crank it all the knobs all the way up and use a chopstick or sharpie or any other non conductive instrument to move the wires around a bit to see if the hum disapears. If you cut any of the zip ties and re-tied them make sure all the wires are in the same bunch. I usually take a few digital photos before I disassemble the PCB.

Best of luck