I've never seen a manufacturer recommended a specific knob
Your question is a little bit confusing, or maybe you are a little bit confused (no pun intended). You want to use a dome knob with a concentric pot right? You can use whatever knob you want.. as long as it fits the pot shaft.. Knobs are purely esthetics.
Just make sure you have a 25K pot for active electronics.
I think he's asking whether or not the knobs for common stacked pots (like the ones stewmac sells) will fit the stacked pots that EMG supplies. I don't know, but I bet someone does.
You both are right! I am confused but I think I see the light now.
Here are two links to the types I was refering to:
http://www.guitarelectronics.com/product/C..._Top_Knobs.html
http://www.guitarelectronics.com/product/C...e_Knob_Set.html
They meant that for EMG concentric pots you can only use the metal flat top knob in this case. I emailed an ebay parts seller and they said EMG pots are different size (I'm guessing the EMG concentrics and not EMG regular split shaft) and this is the reason they say "only for EMG" or only for "CTS" sized shaft.
Now, I totally confused concentric pot with DPDT. My bad! What I really want to know is, do they make a DPDT concentric pot? So for my EMG 89, which already comes with a DPDT, I would like separate volumes for the single and humbucking modes. But I am thinking my only option is to do a mini toggle and then get a concentric pot. It would be interesting if they made such a beast.
Also, I originally said 85, but I am sure it is the 89, the dual mode humbucker. Thanks guys!