I've got a problem with a microphonic gibson classic pickup.
I've tried wax potting with the cover and without but still microphonic.

Anybody got some tips to fix it?

Thanks in advance!
Describe what's happening.

Generally, you do NOT wax pot with the cover on. Worth noting, however, that if it's just the cover banging, you can put a dab of silicon caulk the size of a pea on top of the bobbin before putting the cover back on to prevent any vibration of the cover from producing sound.

You might also describe how you're potting the pickup (let's leave the cover off for now). It may not actually be microphonic at this point -- perhaps you're just getting feedback?

And if you're working with a pickup that was included with a new Gibson guitar, it's probably already been potted.
It's not regular feedback, high pinch squeel when comming close to the amp.
And its there with or without cover before and after repotting.

Potting proces:
- heat wax (parrafine/beeswax 80/20%)
- put pickup in wax
- leave it in there long enough to "heat up"
- take out and let coul
- remove acces wax

thanks for the reply
When potting a pickup, you leave it suspended in the melted wax until the bubbles stop. It will produce bubbles as wax displaces air inside the pickup body, until those bubbles stop forming, you still have open space in there somewhere. The last one I did, single coil, took about 10 minutes in the wax.

That's all I can think of, the squeal you describe sounds a lot like a microphonic pickup, and the only reason I know of it would be cured by potting is it wasn't left in the wax long enough. It's hard to tell in text form, if I had the guitar in my hands I would know in 30 seconds.
Hmmm...I wonder what this button does...
And what would you do in 30 seconds to know? Want a sound sample?

I've left it in the wax up to half hour bubbles have stopped...
When I pot my pickups I leave them in the wax for about 20 minutes. When I have cut open the coils and looked at the inside the wax still did not permeate to the center of the coil so if you are having issues with feedback then I'd say to let it soak for a minimum of 20min. Also, I recommend using just paraffin wax because depending on what plants the bees were collecting pollen from bee's wax can sometimes be responsible for corroding the wire plus paraffin is more effective at minimizing feedback. I know that many will argue that bee's wax sounds better but most people can't hear the difference and it's a small price to pay in effort to make the pickup more functional.
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