Buy unmatched tubes and get the culls?

[dcriner]

Tube vendors sell matched tubes for an extra charge. I assume that tubes' characteristics fall along a bell-shaped curve, with most tubes falling reasonably close to the mean and fairly easy matches.

So, when tube sellers run across a tube that's quite a ways outside the norm, I visualize them tossing them in a "reject" box. Is that what you might get if you don't specify matched pairs?

Just wondering.

[Blackburn Audio]

Actually tubes can vary quite a bit in their characteristics. You won't get rejects if you don't buy matched pairs, just tubes that at the time we don't have a match for. Usually we'll get a shipment of say 200 tubes and start testing through them all and marking the boxes with the test measurements and tossing the weak ones. When you are done with all of them you pair up any that test the same and the ones you don't have a match for you sell when people want singles (unmatched) tubes or hold onto until the next shipment when you might get a match for it.



-Matt at Triodeelectronics.com