Category:Super High Fidelity (Reserved for top-end recorders)
Country of Manufacture:United Kingdom
Release dates:1961 - 1964
Speeds: 3 3/4, 7 1/2
Max Reel Size("): 7"
Number of heads: 3
Head Composition: Permalloy
Head Configuration: Stereo
# Motors: 3
Frequency Response:(all 3 dB): 7½ ips: 40Hz -15kHz
Wow and Flutter:less than 0.2 % at 7½ ips
Signal-to-Noise Ratio:52 db unweighted including hum
Sound quality rating:6 / 10
Long-term reliability rating: 6 / 10
First released late in 1961, the Series 420 consisted of half-track (422) and four-track (424) stereo tape decks utilizing the newer Series 5 transport. The model was a bridge between the older Series 4 and the new Series 5 machines and featured separate record and playback heads. This allowed A/B comparison, echo and recording on one channel whilst playing back on the other. The two operating speeds were 7½ ips and 3¾ ips and a newer, smaller VU meter was fitted.
Speed stability: better than 0.5% / Bias frequency: approx. 68 KHz / Rewind speed: less than 1 minute for 1200ft tape (either direction) / Input levels for full-depth recording: Input 1: min 2mV RMS at 1 Mohm impedance Input 2: min 350mV RMS at 0.5 Mohm impedance / Outputs: 1.0 V RMS impedance 5Kohms / Dimensions (with lid): 18½ ” x 17½” x 9¾ high (470 x 444.5 x 247.5 mm) / Weight: 48 lbs 21.8 kg) / half or quarter-track mono