EMT 420 (ca. 1966–1968 onward)

Name: EMT 420
Brand: EMT

The EMT 420 is a solid-state wow and flutter meter, described in period catalogs as a “Messgerät für Frequenzschwankungen” — a frequency-fluctuation measuring instrument. It was the standard tool across the professional tape world for decades: Studer specified it for aligning the A800, J 37, A67, and C37; Philips used it for the N4450 and PRO12; Dual called it out in service manuals for the 1010A and 1212; and Telefunken listed it for the Magnetophon 15A. That breadth of adoption tells you everything about its authority in the 1960s and 1970s.

The 420 A variant, documented in the EMT General Catalog of June 1968, included a built-in test-tone oscillator at 3,150 Hz. It supported both DIN 45 507 weighting and ANSI S 4.3. An optional companion, the EMT 421 A octave filter, connected to extend measurement capability. Gotham Audio also sold the instrument in the U.S. beginning in 1966, under the same solid-state design philosophy as their ME-101/102 series. A 1970 Studio Sound listing described the 420 as a mono version with four inputs at a price of £26 8s (March 1970, p.9).

Little else is documented. No original price, dimensions, power draw, or internal circuit details survive in the sources consulted. A single Austrian listing from 2022 offered an EMT 420 A at €300. It is the only used-market signal found.