This is the updated and expanded version of the Synthesizer Ic where the old 901 series oscillators have been replaced with the new 921 series oscillators.  More panel space is available since the old 907 fixed filter bank has been replaced by the newer 907A fixed filter bank, and the newer 921 oscillator also takes up less space the the original 901 oscillator. Synthesizer 35 has three VCA’s, three ADSR’s, and five oscillators instead of the two VCA’s, two ADSR,s and three oscillators that were in the older Synthesizer Ic. Also, there are now three mixer panels (instead of the two that were in the Synthesizer Ic). The only downgrade is the the Synthesizer 35 does not include a ribbon controller.