RCA JAN 5693 Red Metal Almost Perfectly Matched (1.0%) Pair NOS CV 3699 6SJ7

Drop-in substitute for 6SJ7.  This is an almost perfectly matched pair of RCA JAN 5693 Special Red tubes.  Both of these tubes have JAN markings. Made especially for military use, these tubes have 10,000 heaters and are capable of withstanding 100 G's.  Were they cleared for use in nuclear missiles?  We may never know, but you can bet they'll sound great in your amp.  You would think such rugged construction would mean lower microphonics.

Be wary of other sellers who list their tubes as being matched if they do not give you the test results or the equipment used to test the tubes.

I personally tested these tubes on my recently calibrated Hickok 600a tube tester and the results are as follows:

2,300
2,275