i have one Pioneer A402 int. amp, recently i take it and use it, i notice when i turn the volume dial, there some hissing caming out from my speaker, i think the volume dial on this int. amp having some problem, but i just want to know whether it will spoilt my speaker, since now i am using it now for my music playback...and connected it from my receiver's front channel pre-out...thanks
Sounds like the volume control needs cleaning on the metal part. It will not spoil your speakers--screaching tones are often blasted from speakers during adjustment.
Now the sound may be coming from a problem in the speaker. But I'd clean the volume control connection first and if that doesn't work, borrow another speaker to see if it is the speaker--or borrow another integrated amp to see if that works fine,
If you still have the problem take your amp to the dealership or local electrician if it is under warranty). If not under warranty still take to dealership/electrician and see how expensive to fix. If it is--buy something new.
as I said--sounds like the volume control pot connections needs cleaning. If it doesn't help take the amp to an electrician (preferably one that deals with your brand)--you may need a new volume control pot.