T43 a switchable precision adder and 43 semitone transposer in 4hp theSUMoutput gives the sum of CV inputsAandBand can add or subtract CV inputC. the switches allow to add or subtract1, 2, 4, 12or24semitones so a total of 43 semitones or 3.5 octaves can be added or subtracted from the CV sum. e.g to add a fourth (5 semitones) use switches+1and+4, to add a minor seventh (10 semitones) use switches+1 octand-2 T43uses precision opamps and voltage references in order to give you perfect tuning across the whole transposition range