Author Topic: Marshall jmp-1 230V: How wire the internal transformer to work in 115V ?  (Read 3567 times)



I bought a jmp1 from France (230V), and I have to do 2 mods to use it on 115V.
1/ change the fuse (T80 mA replaced by T160 mA)
2/ wire correctly the transfo. For that, I need your help.  :wink:

As indicated in the jmp1 schematis, I have to wire LK1 and LK3 for 115V.
I think I have to desolder the component soldered in LK2. Should I only solder 2 components in LK1 and LK3 ?
What is the name of these components (see the picture) ?

Thanks guys !


yep, get rid of LK2, then both LK1 and LK3 need to be connected

the component is....well....a piece of wire


Thx for your reply.
I have a 24 gauge wire.
What is the utility of the "black part" ?


So that a pick`n` place machine can grab it and manoeuvre it into the PCB.


Yeah thats exactly how to do it. I have converted a couple myself. I still own my jmp1 (240v uk) they rock, will never part with it

It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !