Up for sale are my Sylvania labeled 6L6GC STR-387. Some call these the holy grail of American 6L6gc's... which i would be inclined to agree. These tubes are beyond warm and musical... they add dimension to your sound. I bought them for an old Mesa/Boogie i ended up selling - which was pretty much designed with that tube in mind; the STR-415. This is the exact same tube as the Mesa STR-415 and Philips ECG STR-387, just with different labeling. As you're probably already aware the history behind these things begins with US amplifier company's needing a more robust 6L6 to handle high plate voltages like an EL34. These were supposed to last 4x longer than VINTAGE tubes, which already last 10 times longer than new ones. In short - this could be the last pair of power tubes you buy for your amp, if you bias and take good care of them.

These numbers came from my tech's old Hickok tester, along with practical use in my amplifier; they show mutual conductance (these had the highest scores he's ever seen for a 6L6gc!!!!) and current draw -

Tube 1 - 5800gm/58.2ma - (115%) 

Tube 2 - 5800gm/57.7ma - (115%)

These tubes were used gingerly in a 70's fender, and they tested EXTREMELY high, even in the NOS range - @115%/115%. They are matched and test within .5ma of each other. Due to the tube retainers in that amp there are some scratches on the bases, which do not affect the operation of the tubes. Please see pictures for further details. Because of this i am considering these tubes "ANOS", but with high NOS ratings. Shipping is set at $8 for the continental US only, and includes full insurance. Please message me if you have any further questions, and happy bidding!