Roland's response was the Juno 6, released in 1982. It used mostly traditional analog technology, with a voltage-controlled filter, voltage-controlled amplifier, low-frequency oscillator, and ADSR envelope generators. However, it also used digitally controlled oscillators (DCOs), analog oscillators controlled by digital circuits. As opposed to the voltage-controlled oscillators (VCOs) of previous synthesizers, which frequently went out of tune, the DCOs ensured tuning stability. According to "Sound on Sound," "The Juno 6 was the first analog polysynth that you could carry onto a stage, switch on, and play with complete confidence that the instrument would be in tune." It also included performance controls, an arpeggiator, and an ensemble effect.