$300 blonde BJ day!!!

[ShortBuSX]

well....it would have been cheap....if you didn't get the tubes!! :

BUt tubes are sooo much fun!!!!

I bought 2 JJ EL84s matched...but then I bought a slew of 12AX7s to mix and match. Torres has a nice Blues Jr tube recipe, Im not such a fan of his(I wouldnt buy from him) but figure he might know something, so I bought all of those same tubes from TubeDepot(and saved money) but then bought 3 other JJ 12AX7 to help me find the right combo...what doesnt work out here may work nicely in my Deville. 8 tubes for $100 aint so bad...its all about flavor and seasoning!:

[ShortBuSX]

Sa-weeeet-ta! New tube day!
They arrived in less than 48 hours! :
Tubedepot rocks!

The reverb tank didnt arrive yet(from Mojo-tone), but it should be here tomorrow.

[ShortBuSX]

The reverb arrived early this morning, Im really anxious to get this hooked up...although Im gonna wait to install my new tubes, I really wanna get an ear for what Im changing out versus what Im putting in. And even though I know new tubes are gonna improve the tone...it just sounds so flippin good right now, I cant imagine how it could improve.

Over the last week Ive been looking online for Blues Jr sites...and I gotta say Im kinda disappointed in the few sites Ive found. BillM's page is alright if you wanna jump right into mods...to bad there isnt a page like Justin's Hotrod pages.

Im really looking for printable top panel diagrams but Im coming up empty.

[ShortBuSX]

Went home at lunch, you know its hard to wait...I didnt get to take it for a test drive for long, but I did get the new Ruby tank hooked up...it works nicely Doesnt take much on the dial, I found 2 a pleasant level and anything more to be a bit much. I cant really compair this new one to the old one much, but this one works, and that is better!

[aeolian]

Nice score!

I've cleaned up an old amp and a guitar case with a damp rag and then go over them with ArmorAll. Looks new after I'm done.

[tunghaichuan***]

...although Im gonna wait to install my new tubes, I really wanna get an ear for what Im changing out versus what Im putting in. And even though I know new tubes are gonna improve the tone...it just sounds so flippin good right now, I cant imagine how it could improve.

Over the last week Ive been looking online for Blues Jr sites...and I gotta say Im kinda disappointed in the few sites Ive found. BillM's page is alright if you wanna jump right into mods...to bad there isnt a page like Justin's Hotrod pages.

Im really looking for printable top panel diagrams but Im coming up empty.

Are you going to do the full adjustable bias mods on BillM's site? If it were my amp I'd probably just do the simple bias mod as listed at the bottom of the bias mods page. Simple, easy and your tubes will last longer.

tung

[ShortBuSX]

Are you going to do the full adjustable bias mods on BillM's site? If it were my amp I'd probably just do the simple bias mod as listed at the bottom of the bias mods page. Simple, easy and your tubes will last longer.

tung

Im thinking simpler is better, I like the way it sounds but I dont like the idea of the power tubes getting that much heat. I dont think I mind the bias(non adjustable) so much but I do think Id like to do that "power stiffening mod" if its what I think it is...doesnt that kind of accomplish the same thing? Theres no bias test point on this amp, so I wont likely be biasing it myself anyways...I just figure I'll have a tech install the correct resistor(s) to get it right where I want it.

Something along the lines of this:

You can bring any BJr much closer to its proper operating point by changing the resistors in the bias voltage divider. This isn't nearly as good as having adjustable bias, but it's way better than the factory values. The stock bias resistors in a green board BJr are R31 and R37, 22K and 33K respectively. (In the cream board, they're designated R52 and R51, also 22K and 33K respectively.) Leave the 33K alone and change the 22K resistor changed to 27K or 30K. The 27K should bring your C- voltage up to around -12.5V from the -10V factory setting, and will cause the tubes to dissipate somewhere between 8 and 9 watts at idle. The 30K resistor in place of the 22K will give you around -13V, which will give you clean, incisive tone. Going too cold makes the amp sound a little cold and gritty, but with as little as-1.9 or-2V voltage drop across the transformer, you can have an extended clean range--very respectable jazz tone.

I may have my tech do the "tone stack mod" while hes in there...just to get somekind of tonal advantage out of the service...but for the most part I want to leave it original and un-muttered. BUt I think I need to do something to keep from burning up tubes or worse the transformer.

[ShortBuSX]

Its taken me awhile to post this, but heres a pic of my new Ruby tank(the black one) and the Accutronics(OEM, gold one). The Ruby isnt much to look at, but it works! I didnt find many options for replacement tanks, it was either Ruby or Accutronics, and apparently the Accutronics have issues for some reason. Id still like to try and fix the OEM one, I think the issue is the wire clips, so I may solder them dirrectly, the Ruby tank works great, so I dunno when Id get around to it.



BTW, I still havent gotten around to replacing all the tubes. I keep plugging it in with the intent of getting a good ear for it...but then she sounds so good that I become content just to play through it as is....but Ive got the next couple days off and my roommate is out of town, so I may tinker round with it then.

[duhvoodooman***]

Are you going to do the full adjustable bias mods on BillM's site? If it were my amp I'd probably just do the simple bias mod as listed at the bottom of the bias mods page. Simple, easy and your tubes will last longer.

tung

I did three of the BillM mods on my Blues Junior and liked them all--

• The Twin stack mod: Absurdly simple--just jumper two legs on the Mids pot; makes the tone stack work like the Twin Reverb's, with a greater range of control on the mids.
• The Tone Stack mod: Nearly as easy; just change two caps to better balance the low-end against the high. Fills out the BJr's tone and greatly reduces it's tendency to sound boxy.
• The "Simple/Adjustable" Bias mod: I e-mailed Bill and asked if he had instructions to do an in-between mod for tube bias. I didn't see a need for being able to adjust both power tube bias values independently, but I wanted more control than just soldering in a replacement resistor for R52. Sure enough, he had instructions for a single trimpot installation that lets you adjust the bias for both tubes simultaneously. Much simpler installation than the dual-pot mod! Since most of us buy power tubes in matched pairs anyway, this seemed more than adequate to me. If anybody wants a copy, PM me and I'll e-mail it to you. It's for the newer (mid-2001 and later) version of the BJr, with the cream-colored PCB.

More details and a photo available HERE.

Though it's not really a "mod" per se, I also changed out the stock Eminence speaker for a Jensen C12N to get that vintage shimmery Fender/Jensen tone. This is the speaker that Fender puts in the upscale Tweed NOS version of the BJr. Sounds just killer played clean with single coil guitars.

[scorona]

DVM - would you happen to have any sound clips before and after the speaker swap? I'd be interested to hear the difference.

Thanks,
Sam

[duhvoodooman***]

Sorry, Sam--didn't do a "before" and "after" on the speaker change.

[tunghaichuan***]

I did three of the BillM mods on my Blues Junior and liked them all--

• The "Simple/Adjustable" Bias mod: I e-mailed Bill and asked if he had instructions to do an in-between mod for tube bias. I didn't see a need for being able to adjust both power tube bias values independently, but I wanted more control than just soldering in a replacement resistor for R52. Sure enough, he had instructions for a single trimpot installation that lets you adjust the bias for both tubes simultaneously. Much simpler installation than the dual-pot mod! Since most of us buy power tubes in matched pairs anyway, this seemed more than adequate to me. If anybody wants a copy, PM me and I'll e-mail it to you. It's for the newer (mid-2001 and later) version of the BJr, with the cream-colored PCB.

IMHO, there really is no reason to match power tubes in a guitar amp circuit. Just buy a matched set from a repuatable dealer. I've heard some techs say that guitar amps sound better with slightly mismatched tubes (5-10mA). Besides, Fender used to just grab two or four tubes and stick them in the amp and called it good. They didn't worry about matching. Although at the time, RCA Blackplate tubes were readily available and they were made to much tighter tolerances than modern production tubes.

The only advantage I can see for the individual biasing scheme is if you have two tubes that are way mismatched.

Also keep in mind that the individual tubes do age differently, even ones from the same batch.

tung

[ShortBuSX]

The only advantage I can see for the individual biasing scheme is if you have two tubes that are way mismatched.

Bill's site suggests its good if the tubes are too well matched as well...like if you wanted that slightly mismatched tone. :

[Tone2TheBone]

I have a Blues Junior with a couple of the Billm mods too. I bought the amp from some guy who did the cool mod with the one resistor swap. It's a lot clearer sounding from a stock BJ with that mod. I myself did the twin stack. Easy to do and makes the mid knob more useable. I also swapped out the stock Eminence for 2 speaker choices...one being the Jensen C12N and the other a Warehouse Guitar Speakers Veteran 30 (a Celestion Vintage 30 knockoff). I agree that the Jensen C12N produces absurdly good Fender clean tones but I found for my purposes that I prefer the sound of the WGS Veteran 30 because I like to play with some overdrive and all out distortion and the Jensen (to my ears) was too shrill. Anyway FWIW....

[ShortBuSX]

Im glad to finally see some BJr talk...I knew a couple of yall had em, but the BJr doesnt seem to get much love here at the fret

Seems like were all in agreement about the mods to do...looks like Ive got the right plan.

Speaker changes, but no tube swaps?

And mine was the only one with a bum reverb???

[Tone2TheBone]

Im glad to finally see some BJr talk...I knew a couple of yall had em, but the BJr doesnt seem to get much love here at the fret

Seems like were all in agreement about the mods to do...looks like Ive got the right plan.

Speaker changes, but no tube swaps?

And mine was the only one with a bum reverb???

I have lots of love for mine. It loves me back when the amp's pushing past halfway on both the volume and master. Forgot to mention that I have J&J tubes in it. Both power and preamp tubes. Also forgot to mention mine is an American made green board Blues Junior.

[ShortBuSX]

Took my BJr in on Friday to my tech.
I had him do the TwinStack mod and had him cool the bias down by replacing a resistor.
Works great, cleaned up the tone considerably, but its taking me a minute to get used to the tone stack.
Cost me $40 and I got it back on Saturday...this guy rocks: