Damsel in Distress with Jadis DPL

I agree that it was probably a tube failure. I've used the same set of Telefunkens in my JPS2 for 13 years and never had a failure.

As long as everything is still in balance between your channels, the bad tube didn't take anything with it. New production tubes go bad just as often as NOS tubes, and some defects are hard to find until the tube has full operational voltage applied to it. Always purchase tubes from reputable dealers(with stringent test procedures) to avoid the occasional high-dollar, NOS counterfeit(from China, etc.).

I should have mentioned: Don't let this experience dissuade you from pursuing NOS replacements for your unit. Their sonic benefits over what's being manufactured today will make your efforts well worth it.

Some NOS tubes may have a lower voltage rating. Take 6SN7 as an example. The NOS 6SN7GT has a max plate voltage of 300V. The newer 6SN7GTA/B have a higher voltage at 450V.

Vett- Look at this data sheet for the old Sylvania 6SN7GTA (http://home.comcast.net/~tubes/Syl55/Get_Page.html?175). It's plate voltage is also 450V. The tube you mention is a 6SN7GTA/B- same designation with a "b" added. That's what the different suffixes refer to on tubes: Slight variations in the basic design. The plate voltages on NOS 6sn7 tubes can vary from 275V to 450V, depending on the design, and the typical contemporary 6SN7 circuit delivers 250V. MS N's unit doesn't take 6SN7s though, and miniature nine-pins don't vary much at all in plate voltage specs(new or old)within the same family. Here's a site that lists the various plate voltages of the most popular NOS tubes within the 6SN7 family (just FYI): (http://home.att.net/~chimeraone/6sn7sound.html)