1962, was an electric upright bass with a full-size wooden neck and a cello-sized Uvex plastic body. The design was purchased from Zorko, re-engineered by Jess Oliver, and manufactured in a corner of Ampeg's Linden, New Jersey factory. It appeared in Ampeg's price list until about 1970, though popular only with bassists in Latin and salsa bands. Guitars by Burns In the early 1960s, Ampeg-branded guitars and basses were produced by Burns of London. These instruments did not sell well because import costs made them too expensive compared to Fenders and Gibsons. Baldwin's purchase of Burns in 1965 ended the association with Ampeg. and 1966–1969, designed by Dennis Kager, etc. In 1966, Ampeg introduced their home-built line of long-scale "Horizontal Basses" (aka "scroll" or "f-hole" basses), both fretted and fretless (reputed to be the first production fretless electric bass). Some with different bodies were produced as the "Devil Bass" with distinctive horns, but the circuitry was identical. Originally using a transducer below the bridge, they were redesigned around 1968 to use a conventional magnetic pickup. At the same time, short-scale fretted and fretless basses, with magnetic pickups, were also produced. Dan Armstrong "see-through" In 1969, the Horizontal Basses were replaced by the Dan Armstrong-designed "see-through" guitars and basses, with bodies carved from colorless acrylic plastic. The transparent bodies contributed to long sustain but were heavy. The guitars incorporated slide-in user-changeable pickups, and the short-scale basses used two stacked coils with a "pan" pot for a wide range of tones. Production of the "see-through" instruments ended in 1971 when Armstrong left the company. Stud series In the mid-1970s, Ampeg had a line of Japanese-made guitars and basses under the "Stud" name. The guitars included the Stud, Heavy Stud, and Super Stud, and the basses included the Big Stud and Little Stud. The Studs were knock-offs of popular Fender and Gibson instruments (although the Fender copies sported rather incongruous 3/3 and 2/2 guitar and bass headstocks). Some of the Stud instruments were poorly built (e.g. the plywood bodies and necks on the Little Stud), while others had good-quality features (e.g., gold-plated hardware on the Super Stud). Hagström distribution In 1971, Ampeg was acquired by Magnavox, which led to a distributorship deal with the Swedish guitar company, Hagström. In 1975, Ampeg and Hagström collaborated to develop their first guitar/synthesizer hybrid using the contact of the strings on the frets as electric switches: In