Blues Junior mods

[tomteriffic]

There's an interesting cream/chocolate Blues Junior at a local store that is yelling at me. I've heard that there's some extra mileage that can be gotten out of them by way of a few tweaks. Can anybody point me at some suitable sites to look into the possibilities before I fall in on this thing?

[bubs_42]

Man, I have not gotten one yet but I'm wanting to pick up a HOTROD Blues Jr, they sound great. I've seen upgrade kits on ebay but other than that I've got nothin fo you.

[BubbaVO]

Is this for the reissue handwired 5 watt Jr that is out now?

[JohnnyB]

I had both a Blues Jr. and a tweed Pro Jr. back in the late '90s.

The BJr is one way to go; I sure don't know about the mods, but its speaker is probably the first thing to swap out. I found it to be slow, cardboardy-sounding, and imparted what eventually proved to be a fatiguing pernicious coloration no matter what I plugged in or where I twisted the knobs. That's why I got rid of mine.

You might also look into a Traynor YCV20 or YCV40. If you like it you might save yourself a bunch of mods and replacement parts. IMO those are much better amps--faster, better sounding, more rugged, greater range in both volume and tone, and they come in at about the same price on the used market.

[Hamer95USA]

There's an interesting cream/chocolate Blues Junior at a local store that is yelling at me. I've heard that there's some extra mileage that can be gotten out of them by way of a few tweaks. Can anybody point me at some suitable sites to look into the possibilities before I fall in on this thing?

I was looking at a Blues Junior for my low wattage combo amp collection. I like the 15 watt output, 3 band EQ and 1x12 combo setup, but noticed a lot of complaints in its stock configuration. You might want to check out of Bill M of Bill M Audio: Bill M Audio He's the "guy" for Blues Junior mods. If you're good with a soldering iron there's a lot of information on how to do Blues Junior mods on his website. Very cool!!

Is this for the reissue handwired 5 watt Jr that is out now?

No. He's referring to the Blues Junior which is 15 watts and uses EL-84 power tubes.

Guitar George

[tomteriffic]

There's an interesting cream/chocolate Blues Junior at a local store that is yelling at me. I've heard that there's some extra mileage that can be gotten out of them by way of a few tweaks. Can anybody point me at some suitable sites to look into the possibilities before I fall in on this thing?

I was looking at a Blues Junior for my low wattage combo amp collection. I like the 15 watt output, 3 band EQ and 1x12 combo setup, but noticed a lot of complaints in its stock configuration. You might want to check out of Bill M of Bill M Audio: Bill M Audio He's the "guy" for Blues Junior mods. If you're good with a soldering iron there's a lot of information on how to do Blues Junior mods on his website. Very cool!!

Is this for the reissue handwired 5 watt Jr that is out now?

No. He's referring to the Blues Junior which is 15 watts and uses EL-84 power tubes.

Guitar George

I found Bill M's site. This kind of stuff is doable, as long as I don't have to get at the bottom of the board. Looks like a giant pain and frught with possibilities for disaster.

John, I'm not really shopping for anything else in this ballpark. I've got a small wall of low watt combos I like. This particular one was an unusual color combo that sounded pretty good at low volumes. I had heard of it's drawbacks, though, and though it might make a cool addition to the wall if I could (A) get it at the right price and ( do a some mods myself. I'll see what I can do at the shop.

[Thundernotes]

Tom- I copied this from the Blue Guitar website ( http://www.blueguitar.org )

Wed Apr 7 06:59

Dave Stork

dstork@ibm.net

A friend stopped by and asked for a simple, reversible mod

to juice up the preamp in his Blues Jr. and increase the

reverb depth slightly. He's an apartment dweller and he

wants to be able to get a hotter crunch tone at low volume

without ruining the amp's ability to produce a good clean

tone. Here's what I came up with on short notice:

Change R3, R10, R30 and R39 to 150K.

Change R5 and R44 to 220K.

Add 22uF/25V across R38.

After the mod, the preamp produced a nice bluesy crunch

even with single coils. The dynamic character is good... it

cleans up nicely as you let up on the pick or turn down the

guitar volume. The increase in reverb depth is subtle, but I

didn't want to increase R44 beyond 220K let the reverb

driver be driven into clipping.

Blues Jr. owners who are looking to try something different

might want to give this mod a try. It's easy to do (if you're

used to working with PC boards) and is easily reversed if

you don't like it.

When posting critiques, please bear in mind that this mod

was requested, designed, installed and tested in the space

of one hour :-)

Dave:

If it's okay with you I'd like to add your mods to a

blues_jr.txt file to go with the schematic on my site. (I may

dig through the archives here to add other suggestions, too.)

BTW I think you were going to post some mods you had

done to a Pro Jr awhile back. Maybe you can post them to a

new thread when you get time to dig them up...

Thanks!

Steve Ahola

P.S. I just noticed that the Blues Jr has an extra triode

(V2A)- could probably have a lot of fun experimenting with

that! Like adding a cathode follower before the tone stack,

or an extra gain stage like a Boogie Mark I...

For the benefit of others looking for these resistors in the

schematic...

R3 - Rp for V1B (100k to 150k)

R10 - Rp for V1A (100k to 150k)

R30 - Series resistor on Treble wiper (10k to 150k)

R39 - Rp for V2B (100k to 150k)

R5 - Resistor to ground from Volume wiper (130k to 220k)

R44 - Resistor to ground on input of reverb IC (120k to

220k)

R38 - Rk for V2B (add 22uF/25V Ck cap)

Quick'n'dirty ain't bad! Thanks again!

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

And here are some Blues Jr. tips from Randy of Tone Lizard Amplifiers:

1)Of course increasing R4 might send the reverb driver into clipping.Do

you want more reverb depth? Increase R50. Try 390K or 470K.

2)Put in a 250K master (use the part # for the treble control). You can

debate about removing R40.

3)Jumper R18. Debate about the value of R17.

The phase inverter looks like a spot for a few other ideas:

4)Reduce R13 to 10K

5)Reduce R16 to 100 ohms

6)R26 is the presence control as it were. Play with the value or!

short it out for full effect.

I guarantee these will work, and better. Please, this is no battle of

the techs, just a tip from someone who has 'been there, done that!'

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

[Jimbilly]

My old bandleader had one, he swore that a Vintage30 did wonders for it, some good tubes helped too. If it were me I'd start with speaker and tubes and give it a good test before plugging in the soldering iron.

Matt/tremolux gets regular gigging use out of his ProJr, he runs it through an Avatar 2x12. I've heard it, it sounds really good, I think he's got some better tubes in there too.

[Disturber]

My old bandleader had one, he swore that a Vintage30 did wonders for it, some good tubes helped too. If it were me I'd start with speaker and tubes and give it a good test before plugging in the soldering iron.

Matt/tremolux gets regular gigging use out of his ProJr, he runs it through an Avatar 2x12. I've heard it, it sounds really good, I think he's got some better tubes in there too.

Try an Eminence Red, White & Blues in there. Great speaker for Deluxe Reverbs, should work in a blues jr as well, it's my guess anyways. Gives you both good Fender cleans and nice celestion-like breakup.