freestompboxes.org

Hello

This is a nice and rare rack mount tube preamp from the early 90's from Jackson. I have traced the power supply and created a schematic. Its just a simple linear supply.
I was thinking about reverse engineering the whole thing. Leave a comment if you want me to trace the entire thing. If I get enough interest Ill do it.

I posted a YouTube video about it on my channel:


Peace out.
Pete

Hi Pete,

Of course will be interesting to have the schematic diagram to know how this unit was designed.

There is a couple of gutshots found on the web:


Looks as the PCB isn't too complex to extract a diagram:
upload photos

Cheers,
Jose

Nice pics! This scheme may be a good starting point for tracing.

Great preamp - a friend of mine used one of these way back then - nice Marshally sound

We're always interested in any schematics.

Yes a schematic would be great.

Any info on tracing the jx-3?

I rescued my old unit from my parent's garage and started tracing it.
I've only gotten this far, and will have to postpone the rest of it (outputs, switching, psu, etc) to next week, as I will need to properly gut it to check the traces thoroughly.
In the meantime, it is lying open on my bench, so if any questions, I'll be happy to oblige.
Cheers!

Hi have you got any further on the schematic thanks.

Nah, I've had to shelve it for now, as the switching parts were a bit too complicated for me and work & studies are taking most of my time as of now... It'll have to wait until end of semester, but it is still in my backburner. I can post pictures of the boards if you are willing to take it from there.

Yes post the pics see what I can do thanks