Three approaches have been reported:
# FrederickSomerville has wired an Octavider into the output of the lower manual. This allows one to play bass on the LM (but only monophonically.) See http://www1.tripnet.se/~flm/hammond/diff.htm#octavider for Frederick's notes.
# GeoffWilliamson used a bank of twelve home-built dividers to generate the missing twelve tones, and rewired the inputs to the lower manual to transpose it down an octave. See http://www.sympac.com.au/%7eretrojet/LHBass.htm for his notes. Geoff now has his circuit on printed circuit board and has kits available for spinet owners who want to play left hand bass.
-# NigelPiper has successfully wired a Trek II String Bass Unit, normally designed to be played from the pedals, to the bottom one and half octaves of the lower manual. By nulling all but one row of contacts (used for the String Bass) on the left side, and transposing the frequencys up on the right side, the lower manual is split between bass and comping tones (which are now in the right register).
+# NigelPiper has successfully wired a Trek II String Bass Unit, See http://trekii.com/sb-2500b.html
normally designed to be played from the pedals, to the bottom one and half octaves of the lower manual. By nulling all but one row of contacts (used for the String Bass) on the left side, and transposing the frequencys up on the right side, the lower manual is split between bass and comping tones (which are now in the right register).
