help with my lonestar special 1x12

[M.T.99]

I purchased a second hand lonesater special 1x12. I noticed the 5 and 15 watt channel wasn't working but the 30 watt was. Took a look at the back saw the 5y3 was out. Also googled the question and got confirmation on here. I ordered a new 5y3 and replaced it with the old one. Amp worked for about ten minutes than shut off completly. Opened the fuse casing and noticed the fuse blew. Went out to radio shack got a new fuse. Replaced it with the old fuse turned the amp back on and the now the newly replaced 5y3 tube is out. So I am back to where I started. If anyone else experienced this and can be kind enough to offer suggestions I would greatly appreciate it. I have yet to get a second 5y3 tube but I plan on it and see where things go from there.
Thanks.

 

[tle4]

How old is the amp?Is it still under warranty? Mesa has a good transferrable 5 year warranty if it is still under warranty. It does not sound like a simple thing for you to fix yourself and probably needs a tech to do some tests.

 

[Jared Purdy]

I purchased a second hand lonesater special 1x12. I noticed the 5 and 15 watt channel wasn't working but the 30 watt was. Took a look at the back saw the 5y3 was out. Also googled the question and got confirmation on here. I ordered a new 5y3 and replaced it with the old one. Amp worked for about ten minutes than shut off completly. Opened the fuse casing and noticed the fuse blew. Went out to radio shack got a new fuse. Replaced it with the old fuse turned the amp back on and the now the newly replaced 5y3 tube is out. So I am back to where I started. If anyone else experienced this and can be kind enough to offer suggestions I would greatly appreciate it. I have yet to get a second 5y3 tube but I plan on it and see where things go from there.
Thanks.

I have LOTS of experience with this :lol: , regretfully! My advice is to not use a Mesa branded 5Y3, they are Chinese made, and according to a tech at a Mesa authorized service centre here in Toronto, they are junk. I've now got a Sovtek in mine. I mentioned to him that according to the Mesa warranty, if non-Mesa branded tunes are used and something happens to the amp, the warranty is void. He told me not to worry about it and that the amp will be fine, and if anything does happens, the store wil honor the warranty.

My first LSS blew 4 or 5 rectifiers (all Mesa branded) and about 6 or 7 fuses in about 5 weeks before I took the amp back and got a refund. I was convinced it was the amp, but it may have just been the lousy tubes, or it may be some odd electrical anomily in my 100 year old house. The amp is plugged into a good surg protector, and I've checked the circuit where the surg protector is plugged into and it measures okay. So I don't know.

Fast forward a year, and I was missing LSS so much (I tried a Swart AST Master, but it just didn't do clean like the LSS) that I started looking at them again, and managed to find a used one in mint condition, less than a year old, and purchased at the same store where the tech advised me to use a Sovtek. The previous owner never had tube problems, but he wasn't using Mesa tubes, anywhere in the amp. When I got it from him he put all the Mesa tubes back in and within a day of getting it the 5Y3 and the fuse blew! :shock: I couldn't believe it! So I went down to the store where the amp was purshased and had a got talk with the technicians. They admitted that it sounded odd (especially when I told them about my first LSS), but they were convinced the problem would go away with a differt tube. I've had the Sovtek in there for about two weeks now, and no issues. It gets played several times a day, I jump between the 5 and 15 watt setting, no issues. I'm leaving the Sovtek in, and I'll likely try an experiment with another Russian brand, as the Sovtek, as good as they are, rattle a bit. It's onlhy noticeable when the amp is cranked and I'm sitting 5 feet away.

So that's my advice, get a Sovtek!! How old is your amp by the way?

 

[M.T.99]

I will try the sovtek. Thank you for the advice. I'll also post results in due time. As far at how old the amp is I am not sure how do you decifer the mesa serial number? The serial number is LS-0028xx

 

[djw]

I will try the sovtek. Thank you for the advice. I'll also post results in due time. As far at how old the amp is I am not sure how do you decifer the mesa serial number? The serial number is LS-0028xx

There's no publicly available SN/date key out there, but I am pretty sure that yours is an old one from at least a few years ago -- almost certainly in that window during which the rectifier tube bug was in production. Apparently any NOS 5Y3 will do the trick.

 

[Jared Purdy]

I will try the sovtek. Thank you for the advice. I'll also post results in due time. As far at how old the amp is I am not sure how do you decifer the mesa serial number? The serial number is LS-0028xx

There's no publicly available SN/date key out there, but I am pretty sure that yours is an old one from at least a few years ago -- almost certainly in that window during which the rectifier tube bug was in production. Apparently any NOS 5Y3 will do the trick.

If you call Mesa, they'll tell you the exact date that the amp was built.

 

[Jared Purdy]

I will try the sovtek. Thank you for the advice. I'll also post results in due time. As far at how old the amp is I am not sure how do you decifer the mesa serial number? The serial number is LS-0028xx

That's an older amp, for sure. The serial number designation that is identified as being the end of the problem, was around 4400 and below. Above that, Mesa apparently fixed the problem.

Lousy tubes are not Mesa's problem, but then they shouldn't be seeling lousy tubes with their name on them either. I'm not sure what kinds of quality control and environmental testing their tubes go through other than what I have read on their site regarding their tube testing machine. The problem with that is that if the testing equipent is set to certain specifications/parameters that do not include electrical anomallies (which, to be fair, would be impossible to replicate), what ever they are, would make the tests subject.

I have had two LSS 112 amps in my house and both have blown Mesa branded rectifier tubes. The first LSS blew 4 or 5 in less than 6 weeks (and about 6 or 7 fuses). I had a Swart AST Master 112 combo running with a Mesa branded 5Y3 tube, and it (the tube) lasted about 4 months, and then it blew as well. BTW, it lasted longer than the same Mesa tube on either LSS. I had my current LSS for less than 48 hours before it blew the Mesa branded 5Y3 (and the fuse). Now that I have a Sovtek in there, and almost 3 weeks going, no issues. In the same time that I have had the Mesa LSS, I have had several other amps, none of which ran Mesa branded tubes, and none of those amps blew any tubes or fuses.

 

[thom]

My LSS is quite an old one having a serial number in the 900s. The rectifier tube is a Jan Phillips, (stamped with Mesa on the glass) which I believe to be an older tube made to military standards, and of better quality than new production tubes. I have had the amp for about 3 years with no issues. I would recommend you get a New Old Stock tube. I believe that they can be had for reasonable money. I have no idea if my amp has been modified in any way to alleviate the rectifier blowing issue, or indeed if the older serial number amps differ significantly from the later ones....quite curious about that actually.

The Gear Page is a good resource for valve info if you are struggling with what to buy btw.

Good luck, the LSS is a great amp and it would be a shame if this issue ruined it for you.

 

[Jared Purdy]

My LSS is quite an old one having a serial number in the 900s. The rectifier tube is a Jan Phillips, (stamped with Mesa on the glass) which I believe to be an older tube made to military standards, and of better quality than new production tubes. I have had the amp for about 3 years with no issues. I would recommend you get a New Old Stock tube. I believe that they can be had for reasonable money. I have no idea if my amp has been modified in any way to alleviate the rectifier blowing issue, or indeed if the older serial number amps differ significantly from the later ones....quite curious about that actually.

The Gear Page is a good resource for valve info if you are struggling with what to buy btw.

Good luck, the LSS is a great amp and it would be a shame if this issue ruined it for you.

You must have an older Mesa branded 5Y3 as the the current 5Y3 is Chinese made.

 

[M.T.99]

First of all Great Help in here Thank you. I had purchased 1 mesa boogie 5y3 rectifer tube 2 5y3 groove tubes and 1 5y3 sovtek. Got the mesa tubes and the groove tube the sovtek tube was backordered. When I opened the box to the groove tube they were stamped sovtek made in russia... and about 8 bucks cheaper than the mesa tube and the sovtek brand tube. I put the groove tube in and have 6 hours of playing time on the amp with no issues. It appears the problem was with the mesa 5y3 as stated in previous posts. I will post updates on the tube status in the next month or so for others that have or are currently experiencing this problem.
Thanks again for all the helpful information on this board.

 

[Jared Purdy]

You're welcome. Enjoy that fabulous amp!