Hi,I have a Pioneer vex-920 amp that's only a few years old but recently noticed a buzzing coming out of all the speakers (accept sub) after the system has been on a few hours....The amp is in a cabinet (and always has been) with about 3" space around it..
Does the buzzing indicate the amp is knackered?

Thanks
Chalky

Depending on the type of power supply it uses you can get buzzes if the smoothing or voltage regulation starts to degrade. If it only happens after it's been on for a while that suggests it could be heat related.

A 3in gap round the amp ought to be enough in an open fronted cabinet, might not be so good in a closed cabinet though. But might be worth just checking if it is getting warm.

If it is something simple like a capacitor degrading it should be a relatively simple fix. Even a voltage regulator should be fairly easy to swap out. The bigger problem may be identifying the dodgy component(s). With the right tools and skill set it is even possible it could be a DIY job (easy enough for me to say as I've been paid for the last 30+ years to fix electronic gear like this ). But even if you take it to be professionally fixed it is likely to be cheaper than replacing it with a similar class of amp.

Hi chrisjr,
Thank you for the reply, yes the amp is in a closed cabinet so will leave the the front open to see if this cures the problem, if not I'll do as you suggest and have the amp checked out..
Many Thanks
Chalky