Name that mod

[Philip Clements <clements@ziplink.net>]

I just got a BCV console this week and it's in great shape.  Only thing 
wrong with it was someone had improperly added some strange modification.

It's controls are mounted in place of the wood block at the left end of 
upper manual.  It is unlabeled, but has six small on-off type switches
and two knobs.

Inside the organ it was wired to six drawbars.  An AC tap was taken 
from the power terminal strip and wired to a small transformer, whose 
output led to a series of capacitors then connecting to the module.

This device added different harmonics with the panel controls engaged.
Unfortunately, the upper six drawbars on the upper manual's B preset
were reversed.  Pulling the fourth drawbar provided the ninth drawbar's
harmonic and vice versa, etc.

I reversed the solder connections that fed each of the six affected 
drawbars from the mod via tiny gauge wires like phone wire.  This 
corrected my drawbar problem.  However, a loud 60Hz hum was produced.
I couldn't find any bad ground connections.  Touching the control panel
on the mod changed the hum.  

I guess the whole thing was wired backwards.  Even the two volume knobs
got louder when turning COUNTER-clockwise.

I went in and disconnected the unit's AC power supply.  This seemed to 
restore everything to normal.  Except if I turn up the mod's volume 
knobs, some noise is audible.  I just leave them off and all's OK.
I probably should eventually either fix the thing or remove it.

Anybody have any clues about this thing?

Thanks.
Phil Clements
Massachusetts