The 140 was introduced in 1962. It included an enhanced tremolo, which was incorrectly labelled "vibrato" on the control panel. It had a with fixed rate but adjustable depth. Models produced until the early 1960s used vacuum tube circuitry exclusively; the 140 was the first with a transistor amplifier. The model 145 had a tube amplifier and was produced concurrently with the 140. The 145B, the final portable tube model, was phased out in late 1965, while the 140B continued. Around 8,000 140Bs were manufactured. There was a solid-state classroom variant, the 146B, later renamed the 146.