Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: BLUESMAN-2 on December 17, 2025, 10:30:54 pm

Title: POTS IN BLUES JR
Post by: BLUESMAN-2 on December 17, 2025, 10:30:54 pm
Would someone please answer my questions.

the pots in a bj that are labeled 1ma, does that stand for 1 meg ohm ? And the other pots labeled 50kl and 250 kl -- does kl stand for kilo ohms.

And is there a point to point labeled layout for the components on the turrent board?

I would not have purchased the conversion kit if I had known I would have to research for hours and to just find pieces of information.
Thank you,
Blues man
Title: Re: POTS IN BLUES JR
Post by: AlNewman on December 17, 2025, 11:16:15 pm
1MA would be 1 meg ohm audio taper.
50kl, or 250kl would be 50/250 kilo ohm linear taper.

There should be a layout, if you bought a conversion package.

Of course there's lots of schematics for the blues junior, and Hoffman's website has layouts for his conversion, is that where you purchased yours?
Title: Re: POTS IN BLUES JR
Post by: AlNewman on December 17, 2025, 11:20:20 pm
https://el34world.com/Hoffman/files/Hoffman_BluesJunior.pdf

Here's the page for the Hoffman layout/schematic I found, if that's the one you bought?
Title: Re: POTS IN BLUES JR
Post by: SEL49 on December 17, 2025, 11:23:58 pm
Would someone please answer my questions.
Are you asking specifically about Hoffman's Blues Junior conversion?

Quote
the pots in a bj that are labeled 1ma, does that stand for 1 meg ohm ? And the other pots labeled 50kl and 250 kl -- does kl stand for kilo ohms.
1ma means 1meg audio taper pot. 50kl means 50KΩ linear taper pot. 250kl means 250KΩ linear taper pot.

Quote
And is there a point to point labeled layout for the components on the turrent board?
Yes. See page 1 of the Blues Junior pdf (https://el34world.com/Hoffman/files/Hoffman_BluesJunior.pdf).

Quote
I would not have purchased the conversion kit if I had known I would have to research for hours and to just find pieces of information.
Hoffman does not provide "paint by numbers" kits. A certain level of electronics knowledge and experience of tube amp theory and building techniques is required to be successful with a Hoffman "kit".

Title: Re: POTS IN BLUES JR
Post by: BLUESMAN-2 on December 18, 2025, 12:24:30 am
THANK ALL OF YOU GUYS FOR HELPING.
I WILL ALSO BE OF HELP TO OTHERS.