one speaker louder than the other


I am sure this has been discussed so many times but I could not find the specific thread..
One speaker plays louder than the other..what is the most common source of problems?
Can someone direct me on how to find the problem..
I play phono/vinyl/preamp/2 monoblocks/
umaasa
Did you swap speaker sides to see if it follows the one speaker or if it is the room?
Hi Newbie,

Yes ..it follows as I switch the IC from right to left..
This proves that my monoblocks are okey? and perhaps it is a preamp issue?
My preamp is also a tubed system.
thanks for any followup.