This phase-shift oscillator is useful for audio oscillator applications. Adjust R7 for a good sine w
ave. An amplifier gain of 29 is required for oscillation. If C=C1 = C2 = C3 and R = Ri = R2 = R3: Typically, R will be 1 to 100 KOhmhm and C will be 0.1 down to 100 pF, in most practical circuits. As a start, choose R = 10 KOhm and C=0.006 8 (for ~ 1-kHz range).