Installing Isolated Switchcraft Jacks

[The New Steve H]

For some reason, I ordered insulating washers for the switched Switchcraft input jacks on my latest amp. I went to install the jacks, and I saw that it's a pain in the butt. I'm not too sure how it works, but I think I'm going to have to enlarge the holes in the chassis. At the moment, they're just big enough to pass the jacks.

It's pretty confusing. The jack has a shoulder around the base of the threads, and the light-colored inner washer is flat, so the shoulder butts up against it. This means that even if I enlarge the holes, the threaded part will not go all the way in, because the washer will block it.

The outer washer has a raised inner ring which looks like it would fit in an enlarged hole and separate the threaded part of the jack from the chassis.

Without the washers, the jacks fit fine. They're just long enough to clear the chassis and take the washer and nut. With the washers, even if I enlarge the holes, the jacks may be too short.

Are these things really worth the aggravation?

[ToneMerc]

Sounds like the L12A (longer bushing) jack would do the trick.

TM

[The New Steve H]

I feel like installing the jacks without the crap and seeing how it sounds.

[diagrammatiks]

ya you need a long bushing jack and the insulating washers to make it all fit.

or just use cliff jacks or whatever.

[Structo]

You have to enlarge the hole so the shoulder washer fits into the hole.

[The New Steve H]

I liked the pre-isolated Marshall jacks I used on the JTM45, but I noticed plugs fall out of them really easily, so I didn't buy them for this amp.

[ToneMerc]

I liked the pre-isolated Marshall jacks I used on the JTM45, but I noticed plugs fall out of them really easily, so I didn't buy them for this amp.

Make you sure use the Cliff UK marked jacks, any others are clones.

TM

[sliberty]

I liked the pre-isolated Marshall jacks I used on the JTM45, but I noticed plugs fall out of them really easily, so I didn't buy them for this amp.

I have taken to threading my guitar cables through the amp handle as a sort of force field against clumsy feet (mine) stepping on the cable and yanking it from the inlut jack.

If you really need isolated jacks, Cliff jacks are simpler, but I think they also will require an enlarged hole.

[Firestorm]

Look up where you ordered the shoulder washers from: it should tell you the diameter of the shoulder, which is how large you need to make the hole in the chassis. If you are using a plastic (or other non conductive faceplate) you don't another washer on the outside; the faceplate will do. You also don't need the inner tooth lock washer you'd usually use if you were grounding the jack to the chassis. Use the shoulder washer on the inside and if you need to (metal faceplate or no faceplate) cut your own outside washer out of mylar or other heavyish plastic. It only has to keep the beauty washer from grounding, the shoulder washer will keep the threads away from the chassis. On Fender amps with switching output jacks, they also used cute little neoprene washers that fit around the jack sleeve, but inside the chassis hole. Seems like overkill.

[Structo]

I liked the pre-isolated Marshall jacks I used on the JTM45, but I noticed plugs fall out of them really easily, so I didn't buy them for this amp.

I have taken to threading my guitar cables through the amp handle as a sort of force field against clumsy feet (mine) stepping on the cable and yanking it from the inlut jack.

If you really need isolated jacks, Cliff jacks are simpler, but I think they also will require an enlarged hole.

Hehehe, I would rather yank the cable out of the amp than have the whole head crash to the floor.
Because when I go clumsy, I go all the way!

[The New Steve H]

I just assumed the fiber washer went on the inside because it was so ugly!