Vintage Synth Repair

Hi folks,

I've had this funny problem with my A-100 that I just can't get rid of.  When I turn the organ 
on, as soon as the Leslie warms up, I hear a sound as if low notes were stick.  Then, I turn 
the vibrato/chorus selector about 2 full clockwise turns and the noise disappear.  When I 
select either Vibrato I, II or III the sound is chopping but if I select the Chorus I, II or III it 
sounds fine.  I've rebuilt the Scanner Vibrato twice without luck.

Does anyone can help me?

Alex

--- In vintagesynthrepair@yahoogroups.com, "alexparrca" 
<alexparrca@...> wrote:
>
> Hi folks,
> 
> I've had this funny problem with my A-100 that I just can't get 
rid of.  When I turn the organ 
> on, as soon as the Leslie warms up, I hear a sound as if low notes 
were stick.  Then, I turn 
> the vibrato/chorus selector about 2 full clockwise turns and the 
noise disappear.  When I 
> select either Vibrato I, II or III the sound is chopping but if I 
select the Chorus I, II or III it 
> sounds fine.  I've rebuilt the Scanner Vibrato twice without luck.
> 
> Does anyone can help me?
> 
> Alex
>
Hi Alex.
This is general advice until I can get to my drawings.  If the 
scanner has been rebuilt then the problem may be in the vibrato 
switching or the delay line. Are you familiar with the term DENDRITE 
as applied to Hammond organs. It is a whisker growth that is almost 
invisible to the naked eye. It usually builds up between plated 
metal parts and can short out part of the delay line. It can be 
blown away by 18 volts derived from two nine volt batteries.  I had 
this problem on my X-66. Google Dendrite in Hammond organ and get 
back to me if you think I can help further.
Best regards. John.

Hi,

Thanks for your reply.  I've read about the term.  Can you tell me how  
to do it?  Does it potencialy damage the organ?

On 26-May-08, at 6:42 PM, johnx66uk2003 wrote:

> --- In vintagesynthrepair@yahoogroups.com, "alexparrca"
> <alexparrca@...> wrote:
> >
> > Hi folks,
> >
> > I've had this funny problem with my A-100 that I just can't get
> rid of. When I turn the organ
> > on, as soon as the Leslie warms up, I hear a sound as if low notes
> were stick. Then, I turn
> > the vibrato/chorus selector about 2 full clockwise turns and the
> noise disappear. When I
> > select either Vibrato I, II or III the sound is chopping but if I
> select the Chorus I, II or III it
> > sounds fine. I've rebuilt the Scanner Vibrato twice without luck.
> >
> > Does anyone can help me?
> >
> > Alex
> >
> Hi Alex.
> This is general advice until I can get to my drawings. If the
> scanner has been rebuilt then the problem may be in the vibrato
> switching or the delay line. Are you familiar with the term DENDRITE
> as applied to Hammond organs. It is a whisker growth that is almost
> invisible to the naked eye. It usually builds up between plated
> metal parts and can short out part of the delay line. It can be
> blown away by 18 volts derived from two nine volt batteries. I had
> this problem on my X-66. Google Dendrite in Hammond organ and get
> back to me if you think I can help further.
> Best regards. John.
>
>
>