Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: scbobk11 on January 02, 2018, 10:02:55 am

Title: Add Meat Control to stock Blues Junior?
Post by: scbobk11 on January 02, 2018, 10:02:55 am

Well, it's not exactly stock as I've done some of the Billm mods to it but I'm in the process of doing more repairs on the circuit board but not quite ready to do the entire mod to point-to-point wiring...although that's in my plans going forward.

So the question is: How can I wire the Meat Control into my (mostly) stock Blues Junior circuit board?

Thanks...

Bob K

Title: Re: Add Meat Control to stock Blues Junior?
Post by: sluckey on January 02, 2018, 11:34:54 am

Refer to pages 7 and 8 of the BJ Service manual...

     http://el34world.com/charts/Schematics/files/fender/Fender_Blues%20Junior%20Service%20Manual.pdf

1. Drill hole and mount 1MA Meat pot.
2. Remove R27 (75KΩ) from board and solder R27 to one end of meat pot.
3. Unsolder violet wire from P13 on board and reconnect violet wire to free end of R27 on meat pot.
4. Solder a new wire to P13 on board and connect the other end of new wire to wiper of meat pot.
5. Install 22µF cap on board where R27 was just removed. ***Negative side must connect to P13.***

That's all.

Title: Re: Add Meat Control to stock Blues Junior?
Post by: scbobk11 on January 15, 2019, 05:40:16 pm

The mods you describe look like they are for the older green board.  What about the cream board? Mine is labeled 2003.

Title: Re: Add Meat Control to stock Blues Junior?
Post by: sluckey on January 15, 2019, 05:58:05 pm

green board? cream board? I don't know. You'll just have to locate the correct schematic for your board and work between that and Hoffman's schematic. That's what I had to do to give you the instructions above. Sorry they are for the wrong board.

Title: Re: Add Meat Control to stock Blues Junior?
Post by: scbobk11 on January 15, 2019, 08:05:28 pm

OK. Thanks.

I'll see if I can figure it out.

Title: Re: Add Meat Control to stock Blues Junior?
Post by: sluckey on January 15, 2019, 08:09:25 pm

If you will post the correct schematic for your amp I'll take a look and help if needed.

Title: Re: Add Meat Control to stock Blues Junior?
Post by: sluckey on January 16, 2019, 10:33:11 am

I've had time to look at the various revisions this morning. The schematic is the same in the area where the meat control would go. The actual board layout is different, but this mod revolves around R27 regardless of which revision you have. My instructions above can be used for any revision (that I've seen).