Printed in silver ink around the glass envelope of 13 objects.
Printed in silver ink around the glass envelope of two objects.
overall: 2 1/4 in x 7/8 in x 7/8 in
This record consists of 15 tubes, two of which are labeled 12AU7A. The 12AU7 is a medium-mu twin triode in a miniature nine-pin glass envelope. The 12AU7As are made by Sylvania; the rest are from Westinghouse. Each tube in this record has a unique number stamped in yellow ink around the envelope. Six tubes have an off-white dot painted on the top near the tip; four have a yellow dot; three have an off white dot and green dot; one has an off white dot on each side of the tip; and one has two off-white dots on top of the tube and a green dot on the side of the tube near the top.