Gain pot engender Hum at mid level?

Hello, i just add a volume pot to my shruthi (10k A), but when i turn it, a high level it’s ok, at mid level, i have a hum or ground noise, and at low level it’s ok. What the hell ? Does i have to connect the middle pin to a ground point ?

Thanks !

What is the middle pin connected to?

middle pin connected to middle pad

i used this schema. There is no place to error. Is my pot dead (it’s a new one) ?

You have to be careful about where your cables are running. Twisting them helps.

ok, i will check that this evenings

cables twisted, but hum persist, i will try to put sone aluminium foil on it maybe it’s some interférence…

Hum in the middle range of a pot is quite common in guitars and basses so you could try the standard recipes for getting rid of it… First of all, keep all wires as short as possible. Either twist them together tightly or, better still, use shielded wire. For this application I think you could use a wire with two conductors and a shield. Use the shield for making the ground connection, the yellow one in the diagram. Connect the pot housing to ground as well (you may have to use a knife or sandpaper to rough up the surface so solder takes on it). Hum is also very dependent on the environment - turning off a light or moving a bit further away from an extension cord could make it go away. OTOH, setting up for a gig under some stage light can make it appear if it never troubled you before. Very devilish character, that Mr. Hum…

@fcd72: now I am certain it IS you…

Nope. I have a Hameg, not a hp . . . .

Thanks ByteFrenzy ! Ok, i will try that, using 2 wire shielded cable is a good idea, i will back to you !