Ampex recorders are well known as some of the best built and highest quality American professional reel tape recorders. The Ampex Electric Company of Redwood City, CA was the premiere manufacturer of tape recording equipment following WWII.
Ampex Model 300, the mechanical parts were designed by Harold Lindsay and electronics by Frank Lennert. It used 10.5 inch reels, 1/4-inch tape facing inward, and was a two-speed machine switchable to either 7.5 or 15 ips. Harold designed a new head that, when compared to the one for the 200A, was less expensive, performed better and was more uniform from head to head. The new head made tapes more easily interchangeable from machine to machine than was possible between 200A recorders. The first production Model 300 was shipped in late spring, 1949. A 15/30 ips version, the Model 301, was introduced shortly after that. The 300 transport became the platform for many versions of both audio and instrumentation recorders. Overall about 20,000 of these transports were produced.
In the mid-50s, Ampex introducted the Model 600, which was the first small portable recorder that was still high quality. Because of their sustained quality and durability, they said their recorders were ideal for professional and non-professional users in custom home installations or studio uses. This model can be operated either horizontally or vertically. It is designed to handle 7" or smaller reels and to operate at a tape speed of 7 1/2" per second.
The Ampex Model 601 is a lightweight, portable, magnetic tape recorder designed for professional use. It operates at 117 volts, at 50 or 60 cycles per second. It has a tape speed of 7 1/2 or 3 3/4 ips, and has a full or half track head assembly. It can be operated in either a horizontal or vertical position. The microphone input is conveniently located on the control panel, and accommodates any high impedance microphone.
The Ampex Model 612 Tape Phonograph is a tape playback machine which has been especially designed for the stereophonic reproduction of magnetic tapes. This model is also capable of playing back both the conventional half track and full track recorded tapes. It is composed of a tape transport mechanism and an electronic assembly. The transport mechanism handles 7" or smaller reels and operates at a tape speed of 7 1/2" per second. The electronic assembly provides two identical but separate preamplifier channels.