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previous: Carlo This is in reference to a solid sta... -- 9/12/1998 9:11 AM View Thread

Re: Hum Problem

9/14/1998 6:46 AM
R.G.Re: Hum Problem
Could be a number of things. A delay of several seconds to several minutes is often indicative of a thermal-related problem where something shorts or opens or gets flakey or better after it warms up.  
 
Unfortunately, there isn't any good way to define it down to something you can fix easily in a solid state amp the way it is in a tube amp (per the Tube Amp Debugging Page). If it's usable, use it, just bearing in mind that at some point it will fail more solidly. If it isn't usable or the waiting bothers you, take it to a competent solid state tech.  
 
If YOU are a competent tech, watch the power supply voltage for excess ripple, then start walking through the amp input to output, looking for which stage the hum starts in. Once you have the source isolated, you can find the cause or shotgun it.