bad input jacks on Fender SS Princeton Chorus, replacement ???

[jskeen]

Buddy brought in a Black knob, Pre DSP amp the other day, with the standard complaint that the input jacks were bad. I told him, Hey, no sweat dude, I owe ya for those bass lessons you gave my son before he decided that it would be easier to become a Youtube sensation than a real musician, or even a bass player. I'll swap those plastic, board mounted input jacks out for some switchcraft's and they will last till long after the amp is dead.

Of course THEN, I looked at the schematic and figured out that these are not the normal 4 pin mono jacks, hell no, that would be too easy. They used the 9 pin switching stereo jacks for some unknown reason, even though the ring contact arm is not connected at pin 3. It looks like they were switching the + and - 8V supply around with the mechanical switches in there for some reason.

So, question is, Can I sub in a switchcraft shorting jack and just it into the ground and signal slots on the board, or am I going to have to put those useless damn plastic POS's back in?

Here's the schematic and a better mechanical illustration of the jacks.

[Jazz P Bass]

You will lose the "inhibit' function unless the original jack is used.

The jacks themselves are not 'crappy'.

It is when the nut comes loose that all manner of problems crop up.

[Enzo]

Why screw around? Just replace it with the exact part. it will fit the board art, it will cover all the switching functions, it will fit the panel hole.

Does this look like your jack?
Fender Amplifier Jack pc mount mono or stereo, 990912, 990913 | Parts Is Parts - Guitar Parts, Amplifier Parts, Korg Keyboard Parts

[jskeen]

Yes Sir, that's the offender right there.

Really, I can't Hot Rod it with a better part? Aww, Man! (looks down, shuffles feet)..... Ok I guess I'll just put a new plastic jack in there and tell buddy to loop the cable through the amp handle before he plugs it in.

I wasn't really looking forward to fabricating the isolation collar to keep it from grounding the front panel anyway. And Now when he asks why I didn't use the switchcraft jacks, I can say "cause Enzo said not to" Full stop, no more complaining after that :-)

[Jazz P Bass]

I use a very, very, very small (did I say small?) drop of super glue on the nut threads.

[Enzo]

Jazz, I am going to find you, and smack you on the nose.

[g1]

lol. They do make non-permanent loctite for that.

Part of the issue here is we've gotten too used to the kind of abuse the metal jacks can take and treat our gear more rough than we should.
Consider a blackface fender that falls on it's face (with guitar cord in) and the jack is tough enough so the front panel of the chassis bends. Try to straighten that out. Quite a bit more work than replacing a plastic jack.

[Justin Thomas]

Straighten the faceplate out? Meh... that's mojo. And, why the heck should we have to treat gear like Faberge eggs or whatever? Screw that, this is R&R, not chamber music!

Hey, I prefer to get my special effects by kicking the amp, anyway...

Justin

[g1]

And, why the heck should we have to treat gear like Faberge eggs or whatever? Screw that, this is R&R, not chamber music!

Hey, I prefer to get my special effects by kicking the amp, anyway...

Justin

This makes me think of a video (that I can't find) with satriani pulling his amp down the road by the cord .

[Enzo]

And I suppose we just toss our guitars on the floor when we stop playing. And who needs steenking boxes around our tubes, just ship them in an envelope.

When I design or build an amp, I tend to expect the owner will at least care enough about it not to toss it on its face, at least without pulling the plug first. Accidents happen, but really, designing so face smacking is bullet proof?

Marshall has used Cliff jacks for centuries, they are plastic, and no one bitches about them.