This is a quick one.
I’ve recently been looking into playing with directly heated triode single-ended triode (DHT SET) amps, particularly 45s, 2A3s, and their cousin, the 6B4. So I’ve been buying them piece by piece on eBay, as inexpensive parts pop up here and there. The upside is the low low price! The downside is that my ‘modern’ Eico 667 tester doesn’t have the old UX4 socket. Eico did make an adaptor, however–the 615:
It isn’t a terribly easy thing to come by these days, nor cheap when you can find one.
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