[HAM] Generator output levels

[Kon Zissis]

Hi Alan and everyone.
Yes most of the wax capped TG's in my TG spreadsheet do seem follow the
similar predictable drop off characteristics in the TG notes 49 to 91
range. Another interesting particular characteristic  of many of these
aged wax capped TG's is that TG notes 49 to 91 follow a particular
pattern whereby the TG note 49  abruptly drops off in output level and
then the following TG notes gradually  rise up in output levels until
the TG note 72 and then there is an abrupt output level drop off  at the
TG note 73 and then again the following TG notes gradually  rise up in
output levels  until the TG note 91. 
 
I like the sound  of organs with the capacitors working properly and I
also like the mellower or "smokier" sound of organs with aged wax caps.
In order to be able to realistically achieve both sounds on my 1962 C3
which has the still in proper  specs red mylar capacitors brass tray
that I transplanted  from a 1970 T-300  , I have added little switches
in parallel with each of the red mylar capacitors and these switches
which are three position switches  bring in smaller  capacitor mfd
values in parallel with the red mylar capacitors thus  deliberately
increasing the total mfd values  to  levels similar to that of aged wax
capacitors. 
The little three-position switches with the extra capacitors are
connected to the red mylar capacitors  via wires and  the switches
dangle under the lower manual  so that I can easily reach them when
playing the organ.
 
 The switch position 1  allows the  red mylar capacitors to function
properly  for the normal proper specs "new organ" sound. 
The switch position 2 brings in smaller mfd value capacitors in parallel
with the red mylar capacitors so that the total mfd values  are
increased by around 20 % thus  recreating the  effect of wax capacitors
that are around  fifteen to twenty years old.
The switch position 3 brings in smaller mfd value capacitors in parallel
with the red mylar capacitors so that the total mfd values  are
increased by around 50 % thus  recreating the  effect of wax capacitors
that are around  fifty or more  years old.
 
I normally  set all of these switches to the "new organ" setting  and I
sometimes set them all to the "50 years aged wax caps " setting but
because there are individual switches for each of the TG notes 49 to 91
, I can randomly set the switches  to any of the three combinations thus
allowing  many useful variations in  tone  and a simulation of the
random ageing effects  of  the wax capacitors.  
 
In the TG spreadsheet data of my 1962 C3 you can see  the three
different output curves of the TG notes 49 to 91 with the   three
position aged wax capacitor simulation switches and you can see the drop
off characteristics in the  TG notes 49 to 91 with the 50 years aged wax
caps switch  setting which are similar to the output curves of the other
wax capped TG's.
The "variable vintage" effect created with these  switches really does
allow my C3 to be very versatile because I can easily switch between
the sound of a "new" organ and a "sweet mellow vintage" organ .
 
> Maybe in another 10-15 years, however, I'll find my B2 too mellow and
I'll be looking to re-cap (or find a mylar-equipped >replacement).
 
It might possibly turn out that the wax caps in your B2 have reached the
limit of  their  drift up in mfd value so that there might be little
change in the sound  in another 10 to 15 years.  Last year I measured
the TG output levels of a 1937 BC organ that has the brown cardboard
tube covered wax capacitors and the output levels of  the TG notes 49 to
91  follow a similar pattern to that of the 1940's , 50's and early 60's
wax capped TG's . Knowing that the wax capacitors  in this BC organ are
seventy years old I expected the TG notes 49 to 91 of this 1937 BC to
have very weak  output levels and to sound very dull but in fact this
1937 BC has a very nice sound with plenty of brightness. This BC whose
serial number is below  5075 does not have the manual tapering scheme
and this is a factor in it's  very nice sound. The owner of this BC has
put an AO28 preamp in it and he also owns a chopped 1950's C3  which has
a wax capped TG salvaged from an early 1950's B2 or C2 or RT2 organ.
Both the BC and the C3 were connected to a Leslie 760 via the combo
preamp and I did an A/B listening test and I ended up  liking the sound
of the 1937 BC more than the sound of the chopped C3 which sounded a
little muddy compared to the BC.  This 1937 BC is one of those organs
that sound very nice as is  with the aged wax caps. 
 
>  I'll look forward to hearing more reports from you as your research
continues.
 
I have finally finished  compiling all the new TG output levels data
into my updated TG spreadsheet and hopefully it will be  available on
Hammond Wiki  by tomorrow or within the next few days  so that anyone
can look at it and download a copy.
 
All the best.
Kon
  
  Alan Lenhoff wrote:
  Thanks for your detailed response. I'd read some of your explanations
of this before, but I 
  always wondered what would be the purpose of measuring all these
different tone generators
   if the capacitors aged in random and unpredictable ways, as many
suggest.  But it seems 
  to me, after really studying your data, that while there may be
exceptions, most of the 
  waxed capped generators do seem to be headed toward a relatively
predictable result, with 
  significantly diminished output in the 49-91 note range, but little
change in the lowest notes. 
  So, I think you're on to something interesting and important here.
   
  Ultimately, however, it's about what your ears like.  My wax-capped
'54 B2 has that kind of 
  mellow, jazzy sound that I like, and there's still plenty of scream in
the top octave.  My re-
  built preamp and two healthy Leslies help, too, I'd think.  Maybe in
another 10-15 years, 
  however, I'll find my B2 too mellow and I'll be looking to re-cap (or
find a mylar-equipped
   replacement).
   
  To my ears, the late '60s-'70s consoles sound really shrill, but they
probably wouldn't if I 
  played in a loud rock group and needed that edge to cut through the
mix.  (Of course, the
   other factor for rock musicians may be that lots of them suffer high
frequency hearing loss 
  from sitting too close to Marshall stacks for too many years.  For
them, a shrill B3 may 
  sound "just right".) 
   
  I'll look forward to hearing more reports from you as your research
continues.
   
  Alan