Some historical electronic music equipment—the RCA Synthesizer Mk II was designed by Olsen and Bellar, acquired by Columbia Princeton Electronic Music Studio (now the Computer Music Center, where the RCA synth still sits). The two individual modules shown are the 12 tone oscillator and the tube tree (for ramped switching). Other studio photos are from the Columbia–Princeton days, note the custom Ampex transport with an adjustable tape loop guide. Above is an early custom portable mixer (transistor based).

Bode 6402 Dual Ring Modulator from Stony Brook's studio. Columbia-Princeton's early Bode Frequency Shifter (point to point hand wired, transformer in–out, hand labeled frequency dial.)