Why doesn't my clone sound like my B-3?

[bpb@bpbsn.cca.rockwell.com (Brad Baker)]

Why doesn't my clone sound like my B-3?

My Opinion.

My B-3's tone generator outputs 44-48 have audible upper harmonic
components. The outputs from 37-43 have other lower frequency
components. The ones with the filter cap's, 49-91, have other low/high
frequency components that may or may not be audible.

Hammond made some circuit modifications, (R's and C's), to provide
additional filtering for outputs 37-48 to reduce harmonic outputs and
crosstalk.  These circuit changes are not in the Service Manual.
According to Organ Service Company Inc. these were made after the
manual was assembled and didn't make it into the manual. In addition,
there were some people who thought that the changes were not totally
effective.

In conversation with GOFF Professional about these and other
characteristics of the tone generator, i was told that GOFF supplies
these mods in their tone generator rebuild kit.

  (Paraphrasing)
"... don't filter the tone generator too much. If you filter it too
much it won't sound like a Hammond. That's (the harmonics, etc.) what
gives the Hammond its characteristic sound. We filter as little as
possible..."

To get to the point (sorry it took so long), a simulation of the
Hammond with sinewave oscillators, while probably closer to what
Laurens Hammond had in mind originally, is not as accurate a
simulation as one in which the defects of the original are included.
Its defects are what differentiate the tone wheel Hammond from the
field of synthesizers and simulators.

A clone maker's efforts at faithfully simulating the Hammond tone
generator would be like those of the people who cloned the ROM-BIOS on
the original IBM-PC. They had to re-engineer the bugs that IBM let
slip into the original BIOS in order to make their version truly "IBM
compatible".

On the other hand, do we really want there to exist a box that does a
faithful simulation of the Hammond tone generator, defects and all?
Would its existence reduce the mystic or even the intrinsic value of
something which, up to now, has not been duplicated?

Regards,

Bradley Baker
bpb@mlb.cca.rockwell.com