Ex·em·pla·ry HALTRON 6201 / 12AT7-WA TUBE. NOS 1958' HALTRON. THE "PERFECT HALTRON 12AT7/ECC801S/6201. serving as a desirable 6201 = ECC801S tube; representing the best of its kind. IN LOW-NOISE, QUIET, MILITARY SPECIFICATION USA VERSION OF ECC801S.
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