Just picked up a Blues Jr.!!!!

[poweredbysoul]

Hey
picked one up. around a 1998 completely stock.
So far it sounds pretty good, gonna crank it up later today. I am looking at re-tubing it. Looked at the Torres Depot on ebay. They have a set specifically selected for the blues Jr. Called blues forever. To JJ EL84's, TungSol 12AX7 for V2, EH 12AY7 for V1, A "Torres matched" 12AX7 phase inverter for V3.
I also was thinking of changing the speaker out, I have a brand new Celestion G12H30. What could I expect? Gonna play around with it as is for now.
Thanks again for all input!
This thing can sound pretty loud and big!

 

[scottish]

Re: Just picked up a Blues Jr.!!!!

if you want to retube it then id recommend calling up eurotubes and talking it over. That guy (whose name i forget) really knows what he is talking about and will hook you up with a killer set for the amp.

 

[scottish]

Re: Just picked up a Blues Jr.!!!!

Congrats on the score btw. Those are awesome little amps. I own one myself.

 

[super rad stuff]

Re: Just picked up a Blues Jr.!!!!

if you want to retube it then id recommend calling up eurotubes and talking it over. That guy (whose name i forget) really knows what he is talking about and will hook you up with a killer set for the amp.

don't let him talk you into his preamp tubes though, JJs aren't all that great for that, they're very harsh

 

[Hoss]

Re: Just picked up a Blues Jr.!!!!

if you want to retube it then id recommend calling up eurotubes and talking it over. That guy (whose name i forget) really knows what he is talking about and will hook you up with a killer set for the amp.

Bob...

anyways...you're gonna love that amp...but be warned...it loves to be CRANKED!!!

NEW STUFF ROCKS!!! :headbang: :headbang:

 

[jeremy]

Re: Just picked up a Blues Jr.!!!!

it will sound great with the g12h but it will get louder. maybe a good thing, maybe not

 

[SlowGroove]

Re: Just picked up a Blues Jr.!!!!

it will sound great with the g12h but it will get louder. maybe a good thing, maybe not

How would a Swamp Thang sounds in this little amp ?
I heard the BJr does not have all that much bass ...


James

 

[Chickenwings]

Re: Just picked up a Blues Jr.!!!!

The stock speaker is the amps biggest weak point. I put a celestion g12t75 in and it increased the bass response markedly. It is amazing how a 15w amp ca make those fender/eminence speakers bottom out - and the blues junior is not a bassy amp at all (quite the opposite)!

 

[drpietrzak]

Re: Just picked up a Blues Jr.!!!!

If it is in a 1998 model it should be a green board version. There was an amp redesign in the early 2000's. The green boards (I have one) are darker. Not huge bass but not missing either. They can be pretty mid-range voiced in many ways.

 

[DonP]

Re: Just picked up a Blues Jr.!!!!

I have a 1995 / 1996 Made in USA Blues Jr. Green board, "dark sounding" compared to cream.

There is plenty of info on google about this amp. Many suggested modifications and upgrades, speaker swaps.

The G12M Greenback seems to be popular. I have one but it's 16 ohms so I can't use it. You need an 8 ohm speaker.

My reverb wasn't working. I diagnosed it to be the tank by swapping. I bought a new tank. I took out the old one, and found 3 of the 4 wires disconnected from the transformers. I soldered them back together, and now I have an extra reverb tank I don't need.

You'll also find a lot of info about the tubes running hot, and lots of suggestions of changing to an adjustable bias or fixing the bias point. What this boils down to, is that the BJ is hard on power tubes. If you use it a lot, it will eat them up. Mine still has the original Fender GT tubes because I hardly use it. I have too many amps - I power it up every so often to keep the filter caps formed.

In the end after reading all of this, I decided to keep my BJ as-is original. That's the way it came. Who knows, in 50 years people might be looking for original, unmolested Blues Jr's LOL!

If I want a speaker swap, I can unplug the internal speaker and plug it into a 4x12 cab, or some other box. I might decide to do speaker swaping since it's easy to go back to original.

 

[Fresh_Start]

Re: Just picked up a Blues Jr.!!!!

Green board Blues Jr. Weber Blue Dog speaker. JJ EL-84s do sound pretty good. JJ 12AX7s are far from my first choice. An NOS 5751 in the V1 spot is worth experimenting with. A "balanced" phase inverter tube is horse puckey IMHO. Just an excuse to charge more. An EH 12AX7 in V3 works fine. Tung Sol or Shuguang in V1 also good.

BTW half of V2 isn't even used in that amp!

The tone stack is like a Marshall except for more mid scoop (higher value slope resistor).

Bill Machrone is widely regarded as a guru on these amps. Apparently his website is moving so here' the new address:
http://billmaudio.com/wp/?p=1

After my personal experience just adding adjustable bias (a very good idea BTW), modding the insides of this amp seems like a dangerous proposition. Between the ribbon cables, crappy tube sockets, and cheap pots the ****ed thing is pretty fragile.

Chip

 

[SlowGroove]

Re: Just picked up a Blues Jr.!!!!

Green board Blues Jr. Weber Blue Dog speaker. JJ EL-84s do sound pretty good. JJ 12AX7s are far from my first choice. An NOS 5751 in the V1 spot is worth experimenting with. A "balanced" phase inverter tube is horse puckey IMHO. Just an excuse to charge more. An EH 12AX7 in V3 works fine. Tung Sol or Shuguang in V1 also good.

BTW half of V2 isn't even used in that amp!

The tone stack is like a Marshall except for more mid scoop (higher value slope resistor).

Bill Machrone is widely regarded as a guru on these amps. Apparently his website is moving so here' the new address:
http://billmaudio.com/wp/?p=1

After my personal experience just adding adjustable bias (a very good idea BTW), modding the insides of this amp seems like a dangerous proposition. Between the ribbon cables, crappy tube sockets, and cheap pots the ****ed thing is pretty fragile.

Chip

I can't remember (unfortunatly) where i read it (somewhere on the net) but there is another BJr guru out there wjo feels alot of the BillM mods do nothing for the tone, and in fact he (BillM) is actually not addressing the true short commings of the BJr.
I whish i could remember who this bloke is.


James

 

[scottish]

Re: Just picked up a Blues Jr.!!!!

I can't remember (unfortunatly) where i read it (somewhere on the net) but there is another BJr guru out there wjo feels alot of the BillM mods do nothing for the tone, and in fact he (BillM) is actually not addressing the true short commings of the BJr.
I whish i could remember who this bloke is.


James

Bob from euro tubes says that while some of the BillM mods (like the tone stack) are worth while doing...the bias adjustment is an amp killer.

 

[Fresh_Start]

Re: Just picked up a Blues Jr.!!!!

James - please remember where you read a dissenting opinion on the BillM mods. After building a few amps from scratch, I'm very skeptical about some of his opinions. For one thing, he never addresses the weenie power supply filtering and the possibility of a choke. His tones stack mods are attempts to make the amp something other than what it is. Stock is a bastardized Marshall tone stack. Mark Huss has a cool mod to utilize the un-used triode in V2 as a cathode follower before the tone stack. Now THAT's a mod worth looking at! Kind of a TMB 18-Watt with reverb.

I still maintain that better power tubes, a better tube in V1, and a decent speaker make a whole lot more out of this platform. At least until the solder joints/tube sockets/ribbon cables/input jack and cheesy components start to crap out on you.

Bob from euro tubes says that while some of the BillM mods (like the tone stack) are worth while doing...the bias adjustment is an amp killer.

Adjustable bias simply gives you useful control over the amp for a specific set of tubes. How could that be an "amp killer"? Oh, only if you don't put JJ tubes in it maybe

Chip

 

[scottish]

Re: Just picked up a Blues Jr.!!!!

Adjustable bias simply gives you useful control over the amp for a specific set of tubes. How could that be an "amp killer"? Oh, only if you don't put JJ tubes in it maybe

Chip

I dont know enough about amps to say definitively in one way or the other, i was only stating what he has on his website. BillM says that the blues jnrs run too hot and are cooking the tubes. Bob says that the blues jnrs have to run hot to sound as good as they do.

Take your pick, lol.

 

[Fresh_Start]

Re: Just picked up a Blues Jr.!!!!

I dont know enough about amps to say definitively in one way or the other, i was only stating what he has on his website. BillM says that the blues jnrs run too hot and are cooking the tubes. Bob says that the blues jnrs have to run hot to sound as good as they do.

Take your pick, lol.

Taking your pick is what adjustable bias is all about The stock setting runs the bias really hot. Short tube life. I look at the numbers to bias but utlimately go with what sounds best. Slightly cooler than stock suits me fine - longer lasting tubes without changing the tone. Machrone's recommendation is too cold IMHO and using an oscilloscope to set bias is just silly.

BTW Mark Huss is the one who first posted info on adding a cathode follower. Machrone discusses it on his new website but misses part of the point - you can lower the slope resistor and get a fully Marshall tone stack with the cathode follower. If you did the same mod w/o the CF, the there would be way too much gain loss.

Chip

 

[Chickenwings]

Re: Just picked up a Blues Jr.!!!!

Just a note RE: bill Machrone...
He is a professional and a gentleman. I tried out some of his mods on my BJ and they all worked fine. I ended up reverting to stock because that is what i preferred, but that is no reflection on his integrity. Modifications are about making adjustments to a basic recipie to suit your taste. Of course a chocolate cake cannot be modified to taste like a burger, but you can make a chocolate cake with more sugar, chocolate, denser, lighter or whatever. Bill knows his amps and he is really helpful if you want to do some simple and reversible mods to your amp.
PS - the stock speaker is still lame....

 

[Fresh_Start]

Re: Just picked up a Blues Jr.!!!!

Gibson175 - thanks for your comments. Bill Machrone is a very nice guy who willingly shares his knowledge & opinions. My earlier posts came off as more critical than I intended. You hit the nail on the head - modding an amp is like tweaking a chili recipe. Each of us is striving for a different sound.

I still think trying to bias an amp with an oscilloscope is overkill and won't get you the "right" answer.

The Blues Jr. is a poorly constructed amp and every time you pull out that board you risk damaging the ribbon cables, solder joints, etc. But that is to be expected for the price point!

As always, "Bob" just wants to sell more JJ tubes.

Chip