1620

Premium, ultra-low-noise octal 8-pin sharp-cutoff pentode with a top-cap grid, hand-selected and ruggedized by RCA for critical low-level broadcast studio microphone preamps. Equivalents: 6J7, 6J7G, 6J7GT, VT-91 (Note: This is a premium selected version of the 6J7). Real-Life Examples: RCA 76-B2 radio broadcast console mixer, vintage NBC studio microphone preamplifiers, early laboratory sound meters.