JP7 knob removal?

[darren]

So my new (used) JP7 arrived today, and i'm just ecstatic. I can't wait to run this baby through its paces (thanks, Donnie!)

I do want to replace the stock black metal knobs with the rubberized "tank treads" with some nice chrome dome knobs. It'll give it that unified "all chrome" hardware look. But i can't figure out how to get the stock knobs off.

Is there a set screw hiding behind the rubber ring?

 

[Donnie]

Hmmm... it's possible there are set screws under the rubber part.
Sounds like a cool idea.

 

[Shawn]

So you've acquired Donnie's old JP-7, that is awesome, Darren, congrats!

 

[FoxMustang]

From http://www.ernieball.com/site/faq_guitar.php:

Q: How do I remove the knobs on the John Petrucci guitar? There is a grommet over the knob that is difficult to remove.

A: Push the grommet down towards the body (be careful not to scratch the finish). The set screw for the knob will be exposed. Loosen the set screw, remove the knob, then remove the grommet.

 

[darren]

Yep... the trick is pushing the "tank treads" down instead of trying to pull 'em up.

I got the rear-most knob off easily, only to discover that the pot shafts are a wee bit bigger than most, so the knobs i bought don't fit. :/

It's gonna look pretty hot when they're swapped out, though!

 

[Leon]

you know we're going to want to see some pics

 

[Ibanez_fanboy]

sounds complicated

 

[dpm]

Your new knobs must be metric, you need imperial (6mm vs. 6.4mm/1/4")

 

[metalfiend666]

Can you find a matching drill bit and carefully drill out the hole in the new knob?

 

[darren]

Your new knobs must be metric, you need imperial (6mm vs. 6.4mm/1/4")

That's exactly it... though the knobs i got are off by even less than 0.4mm... the tip of a 1/4" audio plug will *just* fit into the hole (for sizing purposes), but it will only sink about 1/8" into the hole. On the Petrucci's stock knobs, a 1/4" plug will fit perfectly to the full depth of the hole.

Time to go shopping!