Expert: Thomas Britanyak - 5/20/2009

Question
I have a Wurlitzer 950a theater organ.  Last night it began to act up on me.  The only way I can describe it is to say that it sounds out of tune.  There is not a particular stop that causes the problem- I checked them all one at a time.  They all cause a slightly wavering out of tune sound.  The effect is more pronounced with higher pitched stops.  When I use the leslie speaker I cannot hear the problem, but it may simply be masked by the wavering of the leslie speaker.  It played fine the day before, but yesterday it began making this strange noise.  I say it sounds out of tune because it sounds similar to a piano that is out of tune.  Right now it is not unplayable, but has a harsh sound.  The sound could also be likened to a hammond drawbar organ with the "chorus" turned on.  I have checked all of my stops and cannot find any external setting that is causing the problem.  Any advice would be most appreciated.

Answer
Hello Jeremy!  I suspect you may have a power supply problem.  Apparently a voltage or two is beginning to falter, one which the voice  generators depend on for stability.  If it turns out a bias or run voltage is in fact the problem, I suggest you have it corrected as soon as possible before the power supply fails altogether possibly causing damage to other parts of the instrument.