20 to 40 minutes prior to adjustment. The Jupiter-4's most distinctive features were provided by virtue of its "compuphonic" digital control of the four voice cards, made possible by a single NEC 8048 microcontroller: An arpeggiator, with a choice of: up, down, up/down, or random mode. The arpeggiator can be prominently heard in Duran Duran's 1982 hit single "Rio." Switches on the far left select between the internal rate, adjustable, or an external source, such as the clock out of its contemporary, the Roland CR-78—a programmable analog drum machine. A hold button on the lower front panel allows users to latch or set a constantly running arpeggiator pattern, useful when playing leads on another machine over a JP-4 pattern. Otherwise the arpeggiation only responds when keys, individual or chords, are pressed. This allows for a more fluid and less rigid timing in live situations when playing with others. Left-hand modulation from the keyboard is unusual. The polyphonic portamento or glide feature can be used very effectively in conjunction with the arpeggiator and any preset. An octave down switch by the modulation wheel is also available independent of memorized settings. Unlike Moog or Sequential, the Roland modulation wheel goes left to right, and is spring-loaded. A short spike on top of the spring-loaded modulation wheel allows for an unusual rapid fanning, but risks damage to this out of production part. Knobs allow depth of pitch bend or LFO modulation, in addition to the amounts assigned and memorized. Toggle switches select bend or LFO to the wheel and onto any combination of VCO/VCF/VCA in an unusual selection pattern, all controlled by a single wheel motion. Four voice assignment modes, which, as well as simple one-VCO-per-voice polyphony, included the ability to affect four-VCO unison when one key was pressed, two VCOs per voice when two keys were pressed, and one VCO per voice when three or four keys were pressed. This effect can be heard on tracks such as "Seconds" by The Human League and "I Dream of Wires" by Gary Numan. The final signal path also included a high-pass filter and a lush stereo chorus effect based on two, now rare, MN3004 ICs. The chorus circuit board is located underneath the modulation wheel, and has a single front button for enabling and disabling the effect. It is lush and wide, supplying a pseudo stereo effect when both audio outputs are used. While