The 71A valve is a classic TRIODE of output power for AUDIO amplification that appeared in the first half of the 1930s, used in the low frequency final stage of radio equipment. Its quality and its level of linearity, in more recent years, have made it very famous also for extraordinary devices, DIY projects and more, HI-FI and HI-End. The Triode 71A is the forerunner of the even more famous Triode 45 which in turn is the smaller sister of the ultra famous Triode 2A3. This is a PERFECT and exemplary PAIR of 71A JAN CNU NATIONAL UNION, genuine produced in the USA, totally NOS/ NIB, produced for US Military supply, therefore excellent quality. Absolutely identical valves, admirable structure with very robust " silver " striped plate, completely similar to the 45 (a few millimeters smaller) and double structure for suspension filament spring. Same code on the base. TOTALLY coupled. Harmony and dynamics in a tube.
EQUIVALENT: UX171A = CX371A = CX71A = TC171A = AC4 = NX-71A = 171A = SX171A = JX-171A = SLX171A = UX-71A = ER71A = ER171A = X-171A = DX-171A = VX171A = AX-171A = 471A T-71A = MX171A = RayX-171A & SUBSTITUTE: M71A and 38071 = AC-116 = U171
DATA-SHEET file at the bottom of the page.