And now for something completely different!

[Boy Howdy]

I have this Acoustic150 (Acoustic Control Corp.). I have a couple questions: First the most important one. HOW THE HECK DO YOU GET THE KNOBS OFF?!

These are of the press on, pull off type (no set screws). I have tugged with such force that I'm concerned about destroying the pots. I've only managed to remove one.

HELP!!!

[nevetslab]

While these don't look like Sifam or Selco knobs, where there is a hex nut controlling a collet-style clamp underneath the knob cap...does the chrome knob cap come off, exposing that style? I don't recall Acoustic eve using that type knob. I'll send an email to their former Chief Engineer Duke Aguiar to see what he recalls.

[TomCarlos]

Be very careful with the knobs. I would recommend putting the cabinet on a couple blocks of wood and allowing some penetrating oil to drip down the shaft and into the knob. Give is an hour or two. Then you can try to slowly pull the knobs off. Forcing the knobs to come off will damage the pots - I should know :-(

[g1]

From other pictures, they appear to be the stock knobs.
Does the one that came off look like anyone may have added some glue? Or maybe they have got stuck, sometimes plastic shafts seem to even expand a bit.
Aside from penetrating oil like Tom suggested, you could try some heat with a hair dryer or heat gun, just be sure not to melt anything.

[Enzo]

I hope no one glued them, but they sometimes do.

I use a pair of church keys. If you try to use a screwdriver under the knob, it tilts the pressure. SO I use TWO keys under opposite edges, using the square end and lever it up

[Chuck H]

And if you don't have two church keys I've done the same with a pair of spoons.

[J M Fahey]

From faint 40 y.o. memories, they used push fit knobs (no sideways screws or concentric under-a-cover nuts) , maybe bare plastic inside, maybe a small split steel ring/tube inside to grab the shaft.

grime may have stuck them together, or some IDIOT might have used a drop of krazy glue.

If presented with that problem, I prefer to crack knobs open with a large wire cutter ,it´s way easier to get a somewhat similar set of knobs, even if not original of course, than getting a new pot.

Faint memories tell me they used some kind of wings to hold PCBs.

Haven´t seen one in years.

[galaxiex]

Knob puller....

https://www.stewmac.com/luthier-tool...ushing-puller/

waaaaaay over priced but does the job with no damage.
Disclaimer, I don't own one.
Too rich for me.

Cheaper one...

https://www.stewmac.com/luthier-tool...t-knob-puller/

.

[Boy Howdy]

I'm almost at the point of refusing to do business with Stewmac, just on principle. Their prices aren't just outrageous, they're obscene.

The double church key idea looks like a good one.

These knobs and pots are weird. They have double bevels, one on each side of the shaft. And there's a metal sleeve that fits between knob and pot shaft. The sleeve slides off easily, at least on the one I was able to get loose (the intensity knob).

I'll have another go at it tomorrow (I'm not home today) and report back.

[TomCarlos]

The StewMac tools do not appear to hold the shaft in place. That is what you need. The shaft does not move, only the knob.

[Boy Howdy]

I'm worried I may have already damaged one.

I'm thinking the penetrating oil is probably the way to proceed initially. Then church keys. We'll see.

[galaxiex]

I'm almost at the point of refusing to do business with Stewmac, just on principle. Their prices aren't just outrageous, they're obscene.

The double church key idea looks like a good one.

These knobs and pots are weird. They have double bevels, one on each side of the shaft. And there's a metal sleeve that fits between knob and pot shaft. The sleeve slides off easily, at least on the one I was able to get loose (the intensity knob).

I'll have another go at it tomorrow (I'm not home today) and report back.

Fully agree with this.
I have not purchased from them for a long time...

[galaxiex]

The StewMac tools do not appear to hold the shaft in place. That is what you need. The shaft does not move, only the knob.

How would you do this when you cannot access the shaft?

All you can do is "pull" on the knob.

[TomCarlos]

How would you do this when you cannot access the shaft?

All you can do is "pull" on the knob.

That is my point !!! Why buy an expensive tool when a home made solution, (or your fingers) can do the same job. If that knob is "stuck" on, you either need some penetrating oil (or silicon spray) to loosen it up or you follow JMF's recommendation of sacrificing the knob while not damaging the pot.

[Helmholtz]

I've been using the StewMac Schatten knob puller since decades (was much cheaper then).
Works great and doesn't mar the top of your guitar like other tools.

I doubt any kind of oil will help with plastic on metal or plastic on plastic

But I might try freeze spray (or a hairdryer as already recommended).