Disklavier

If there is a Hum/Noise comming from within the AMP unit, I am still 
convinced that the only thing that could vibrate and emmit oscillation 
are with coils. IE; Main transformer and the Small transformers on the 
Power supply[pwb board]. I have had to dope[Q Dope] many xformers in 
the past to mute them. Maybe a call to a technician that has 
background in this type of problems would be able to help.

DKVTECH

 
--- In disklavier@yahoogroups.com, "FrJJY" <frjjy@y...> wrote:
> 
> There are actually two noises.  The main noise comes from within the 
> amp box somewhere.  The second noise is as you described:  a 
> vibration caused my the wire mesh and other metal surroundings.  I 
> can quiet the second, but not the main source.  This is a very 
> intermittent problem - happens about one hour for every five of 
> use.  Any other ideas would be greatly appreciated.
> 
> J. Young
> 
> --- In disklavier@yahoogroups.com, "dkvtech1ab" <fatcheson@a...> 
> wrote:
> > 
> > Hello J. Young
> > 
> >  Is it a HUM or is it an occasional rattle-a vibrating sound that
> > maybe mistaken to be a HUM-.? When you hear the HUM which is 
> comming
> > from the AMP unit underneath the piano, simply go underneath and 
> touch
> > the mesh that covers the amp, see if you can make it change. 
> Reason?
> > These units have Hi frequency shunts-shunt being used loosely to 
> make
> > a point- that are like litlle donuts in which the wires are 
wrapped
> > and cancels RF. Now, at times when the distance between the mesh 
> and
> > the shunts are just far enough but close enough to move away and 
> come
> > close just as the field is changing polarities, you will hear a 
> rattle
> > type hum from the AMP but not from the speakers. Same principle as 
> a
> > voice coil just not musical!!!
> > 
> > I hope this helps!!  
> > 
> > DKV1AB
> > --- In disklavier@yahoogroups.com, "FrJJY" <frjjy@y...> wrote:
> > > 
> > > I have a new DC1A with an intermittent problem:  There is 
> > > occasionally a hum that comes from the amplifier - perhaps the 
> power 
> > > supply.  The noise does not come through the speakers but comes 
> > > directly from the amplifier box.  Has anyone else had this 
> problem?  
> > > Unfortunately, the problem disappeared when my tech arrived, but 
> of 
> > > course, reappeared after he left.  Any solutions?
> > > 
> > > Thanks.
> > > 
> > > J. Young