Mesa branded NOS 5Y3 rectifier in LSS

[notyalcer]

New owner of a used LSS here. Love this amp, have read about problems in early models with blown rectifiers. I have an early one based on the serial number (LS-002051). I assumed I would have to get a NOS rectifier soon or risk a dead amp at a gig. Took out what it came with and was pleased to see Phillips JAN stamped in blue on a brown base. It looks authentic compared to other NOS tubes I've had.

Then I saw the MESA brand etched white on the glass. A little searching online yielded the Mesa Tube Sales Reference chart, http://www.mesaboogie.com/Product_Info/TubeReference/TubeSalesReferenceGuide-11-10-08.pdf from which I found this text:

• 5Y3 - The MESA 5Y3 is a true, authentic 5Y3 NOS (New Old Stock) equivalent modeled after the original Phillips 5Y3 and is built to our exacting specification for use in our Lone Star Special - This tube produces a sultry vintage sag, creating a silky, smooth feel on the strings and provides the most sag of all of our rectifier tubes. Stock in: Lone Star Special

My question is is this tube an authentic NOS Phillips JAn tube? Or is it a reproduction meant to look like an old tube? From the above text, it sounds like it could be the latter, but it could also be that Mesa is also reselling real NOS tubes. Anyone know?

Thanks.

 

[212Mavguy]

I think that the word "Equivalent" says to me that it is most likely a special tube request from a modern production facility. No biggie, if it works, it works. Easy enough to get a vintage mil stock 5y3wgt or vintage 5v4ga via fleabay and not have to worry.

 

[94Tremoverb]

You may find that the early amps did ship with genuine NOS Philips tubes. From the description it does sound like one - I doubt a modern repro would have Philips or JAN printed on it. After all, Mesa did have a fairly big stock of NOS Philips/Sylvania STR415 6L6s until quite recently too, so it wouldn't be surprising if they had other NOS types. Then after they ran out they used the "equivalent modeled after" version which is just another new-production tube like all the other "reissues" and will have just the same reliability problems.

What I would do is leave the stock tube in, but buy another genuine NOS Philips or a 5V4GA as 212Mavguy said, and carry it (along with a spare fuse) everywhere you go with the amp. (You probably should anyway!) Then if it's real you'll probably not need them, and if it isn't you have backup .

 

[notyalcer]

Thanks for the feedback. I got some interesting feedback over at the gear page on this thread and I posted some photos:

http://www.thegearpage.net/board/showthread.php?t=812799

That is a wise suggestion, I will get a spare tube. Already have some fuses, not sure if the amp will work in 30 watt mode if I blow the rectifier and change the fuse.

 

[94Tremoverb]

You score! Mike K and Doug are right of course, that is definitely a genuine JAN/Philips tube.

As far as I know the amp will still work in 30W mode, but you probably must physically remove the blown tube before you change the fuse not just set the amp to 30W, since if it's shorted (the usual failure mode for rectifiers) it will still be across the supply.

I agree with you about Mesa's ad copy by the way - the amps *are* good, but the hype really is way over the top... I remember getting my first catalog back in the mid 80s too, and I have to say it was actually counterproductive because when I got to try a MkIII it just didn't deliver what they claimed ("Fender clean, Marshall crunch and Boogie lead with flawless footswitchable accuracy"... or something like that!) and actually put me off the brand for over a decade. The MkIII *is* a great amp (I later realised - at being a MkIII, and nothing else), but at the time I found it incredibly frustrating and disappointing.