Witch hat knobs for CTS pots

mynameistrouble

Hi, 

Can someone please point me in the direction of some witch hat knobs which will fit CTS long shaft 500k pots? Axesrus gives me too many options and it gets confusing…

many thanks
Richard

danishbacon

Check out hosco ones on ebay

BillDL

Count how many splines ("teeth") are on the shafts of your volume and tone potentiometers.  Some people refer to the split shafts with the jagged teeth as "knurled shafts".  The correct terminology is "split-shaft splined" as opposed to a solid round shaft with one flat edge for knobs with grubs screws. The potentiometers with imperial sized shafts usually have 24 splines, (usually) on a 5.95mm shaft (usually just referred to as 6mm) whereas the metric ones normally for the European (and UK) market and Asian imports normally have 18 splines on a 6mm diameter shaft.  Armed with that knowledge you should then be able to go to websites where the vendors specify the fit, for example:

https://www.alegree.co.uk/collections/knobs ; refers to the different sizes as "Imperial USA" or "Metric Import".

There's not a lot of selection there at the moment, but that's just an example of what you need to watch for when buying knobs from anywhere.

On the North West guitars website:

https://www.northwestguitars.co.uk/plastic-guitar-knobs/

you will see a check box to the left to filter the results to imperial or metric.

I stand to be corrected on this, but the Axes R Us website wrongly refers to the knobs as being for "Alpha/Metric 16 spline" pot shafts, not 18, but the USA ones correctly as being for "CTS/24 spline"

https://www.axesrus.co.uk/WithHatKnobs-p/witchhatknob.htm

regardless of whether it says 16 or 18, you will know that if you have 24 splines on your pot shafts you need the "CTS/Imperial" fit rather than the metric fit with less splines.

You would be able to push the softer plastic versions of either type of knob onto either shaft size and spline count, but you would be chewing up the splined plastic shape inside the hole in the knob and it may well come loose quite quickly in use, especially if you remove it and try to push it back on again.

I should add that knobs with grub screws can come in different solid shaft diameters.  Modern ones tend to be 6mm.  USA ones most often have 6.35mm shafts, and there are some "retro" plastic knobs for 1/4" shafts.

mynameistrouble

BillDL said:

Count how many splines ("teeth") are on the shafts of your volume and tone potentiometers.  Some people refer to the split shafts with the jagged teeth as "knurled shafts".  The correct terminology is "split-shaft splined" as opposed to a solid round shaft with one flat edge for knobs with grubs screws. The potentiometers with imperial sized shafts usually have 24 splines, (usually) on a 5.95mm shaft (usually just referred to as 6mm) whereas the metric ones normally for the European (and UK) market and Asian imports normally have 18 splines on a 6mm diameter shaft.  Armed with that knowledge you should then be able to go to websites where the vendors specify the fit, for example:

https://www.alegree.co.uk/collections/knobs ; refers to the different sizes as "Imperial USA" or "Metric Import".

There's not a lot of selection there at the moment, but that's just an example of what you need to watch for when buying knobs from anywhere.

On the North West guitars website:

https://www.northwestguitars.co.uk/plastic-guitar-knobs/

you will see a check box to the left to filter the results to imperial or metric.

I stand to be corrected on this, but the Axes R Us website wrongly refers to the knobs as being for "Alpha/Metric 16 spline" pot shafts, not 18, but the USA ones correctly as being for "CTS/24 spline"

https://www.axesrus.co.uk/WithHatKnobs-p/witchhatknob.htm

regardless of whether it says 16 or 18, you will know that if you have 24 splines on your pot shafts you need the "CTS/Imperial" fit rather than the metric fit with less splines.

You would be able to push the softer plastic versions of either type of knob onto either shaft size and spline count, but you would be chewing up the splined plastic shape inside the hole in the knob and it may well come loose quite quickly in use, especially if you remove it and try to push it back on again.

I should add that knobs with grub screws can come in different solid shaft diameters.  Modern ones tend to be 6mm.  USA ones most often have 6.35mm shafts, and there are some "retro" plastic knobs for 1/4" shafts.

This is probably the most comprehensive answer I've ever had to any question on this forum! Thank you so much, that's extremely helpful.

gavin_axecaster

danishbacon said:

Check out hosco ones on ebay

Note that as standard the Hosco knobs (imperial version) are actually loose on CTS pots. In order for the knobs to not fall off the pots shaft top needs opening up slightly (and carefully!).

I returned an entire batch a few years ago and I'm told the molds still have not been changed.

PhilM

I’ve got a set of 4 black witch-hat knobs currently fitted to some CTS pots. I don’t need them - I can fish them out next weekend. I know they 100% fit CTS pots as I replaced the pots in the guitar, and then had to buy new knobs to fit the new pots.

mynameistrouble

PhilM said:

I’ve got a set of 4 black witch-hat knobs currently fitted to some CTS pots. I don’t need them - I can fish them out next weekend. I know they 100% fit CTS pots as I replaced the pots in the guitar, and then had to buy new knobs to fit the new pots.

PM'd