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CK-5755 (420A) Western Electric NOS

From €8.55 *

*Prices incl. VAT plus shipping costs

In Stock

Standard Matching:

  • S5755
    New Old Stock tubes, not tested for RoHS compliance.
    Only for repair and restoration of historical equipment.
This CK-5755 is a double-triode made by Western Electric (USA) for Raytheon. It has same specs... more
Product information "CK-5755 (420A) Western Electric NOS"
This CK-5755 is a double-triode made by Western Electric (USA) for Raytheon. It has same specs as 12AX7A / ECC83 / 7025 but with different pinout for Pin 2+3 and 6-8 (see data sheet). For use as 12AX7 an adaptor or an adjusted socket wiring for pin 2+3 and 6-8 is required.
Western Electric marked this tube WE 420A for their own brand.
The CK-5755 "features special cathode springs which reduce microphonic response. This characteristic is controlled by a "microphonic stability" test for balance in which the tube is tapped at shock levels of 400 - 600G."  read more in the data sheet.
Read, write and discuss reviews... more
Customer evaluation for "CK-5755 (420A) Western Electric NOS"
10 Jul 2020


I bought a matched pair for the Phonodude designed by Triode Dick. Good matching (less than 0.1 dB gain difference) and excellent sound quality. I bought another pair for my secondary system.

16 Jun 2016

A secret NOS treasure! This CK-5755 is made by Western Electric as 420A (which are selling for about $100 in U.S.) but branded for Raytheon as 5755. In fact they have internals identical to 12ax7. They just need a socket adaptor (or rewiring) to achieve real U.S. made NOS 12ax7 tone in Western Electric quality. Outstanding!

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