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| Top of Tonewheel Generator inside Hammond C3 Organ |
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Old Tonewheel Generator Capacitors ?
Replace them !
All
of them !!
Go on !!!
Do it !!!
The main reason is it'll no longer sound dull in the middle of the
keyboard with sub-fund drawbars pulled all the way out. The bass sub-fund drawbar tends to drown everything out.
The old
wax capacitors deteriorate with age especially after 30 odd years and their value increases.
Its time to bin 'em
Get
yourself a printout of the 'A-100 Theory of Operation Manual' from the following website link coz it helps a lot. It's the
same for C3 and B3 Hammonds.
A-100 Theory of Operation Manual
After desoldering all the old wax caps off they measured over three
times the value of what they are meant to be and what they were originally when the generator was built. This bigger capacitance
leads to a much lower cut off point for the tone, therefore lower frequencies sound louder
ie, it sounds like the
bass pot is turned up to full and the treble turned down. Not nice !!
Replacement mylar type caps will be best but
if you can't get hold of any mylar type caps then try some more available types.
Using axial non-electrolytics which
are cheap, I put six 0.22uF capacitors for frequencies 49 to 54, and forty seven 0.1uF capacitors for frequencies 55 to 91.
Axials are longer than radial caps so they'll reach the terminals on top of the generator.
Frequencies 37
to 48 got the special treatment of a 10ohm 1/2watt resistor and a 47uF tantulum bead added inline between the tone generator
and manual keys. You'll have to view the Technical Bulletin here to mod these or take a lake at the Benton Electronics Website
- click on Service Info then Servicing the Tone Generator then Generator Filters.
Benton Electronics
With a Hammond pre-amp setting of 1 turn (hole thru expression control box in back of Hammond) you get a pretty good sound.
Turn it all the way, 1 & a half turns and it sounds even better !! Dirty!!
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