to complement the existing Combo series. As the name implies, these use silicon transistors that produced more stable tones than the germanium ones used in the Compact series. The organs are contained in a metal cabinet covered with a skin plate and plastic edges, chrome folding legs, retractable carrying handles, and a removable music rack. The Fast 2 has a four-octave keyboard (C to C) with a one-octave manual bass on the left. There are four voice stops (flute, clarinet, reed and strings), all at 8', a two-speed vibrato and an optional swell pedal. The Fast 3 features more sounds, including 16' bass and clarinet, 8' oboe and trumpet, and with 8' and 4' flute. The Fast 4 has a larger five-octave keyboard, with an additional light / heavy vibrato option, two mixture stops and five percussion controls. The Fast 5 adds three sustain stops. Professional Series (1967–1975) The Professional series were the most sophisticated models made by Farfisa, first announced in 1967 and designed to compete with the Hammond. Contemporary advertising emphasised that these series of instruments did not sound like other combo organs and could be used for soul and rhythm and blues effectively. The instruments included sustain, eight different footages, a variety of percussion and vibrato options. The VIP-series organs were announced in 1970, which included a "Synthe-Slalom" foot pedal used for pitch bend. The Professional (Model 222 or N) contains a single keyboard with grey keys. The vibrato uses a phase shifter circuit that is placed after the main oscillators, as this was the only way to make individual controls for each voice work. The Professional Duo is a double-manual version with bass pedals, a swell pedal and a slalom pedal. There is an optional amplifier and speaker unit, the PAS 55, that can be placed between the organ and pedals, to resemble a spinet organ. The Professional 88 was an attempt to make an organ that closer resembled a Hammond. It was followed by the Professional 110, that has a set of drawbars for each manual and a connection to a Leslie speaker. The Professional Piano was an electronic piano. There were two different models, whose main difference was the location of the split point between bass and treble. Later models The Transicord was a transistor electric accordion, and is essentially the circuitry for a Compact-series organ in an accordion-shaped box. There are no reeds;