Southpole
Tele-Afflicted
The 6L6GC tubes in my amp died last night after 18 months of light to moderate use. I was hoping for longer! What is reasonable operating life for this type of power tubes? I’m using Mesa branded tubes.
I had a quartet of Mesa 6l6GCs last me about 15 years in a Mk IV. They still sounded great when I sold it. I wasn't pushing it too hard very often...
I have some JAN Sylvania 6lGCs that came in my Twin. They're from the early 70's and still work fine. I have a pair of GT 5881's that came in my Bassman Ri... I think they're from the 90's. They still sound great.
I agee with @xafinity, if both tubes really are faulty and went at the same time, I'd be a tad concerned. Are you sure it's both and not just one?
It might depend on your definition of moderate use. Do you mean one hour daily or two hours weekly?The 6L6GC tubes in my amp died last night after 18 months of light to moderate use. I was hoping for longer! What is reasonable operating life for this type of power tubes? I’m using Mesa branded tubes.
Varies a bit but on average just a few hours a week. These are STR 440s.It might depend on your definition of moderate use. Do you mean one hour daily or two hours weekly?
Amp fired up ok at start of practice but within 15 mins I could tell I was losing power. Also my clean sound had disappeared and it had a low grade drive sound (clean channel) even with gain set really low. I did my best to compensate but it was sounding pretty dire. After 45 mins output minimal and lots of heavy static sounds so turned it off.How did they die? Describe the death.
What tubes are/were they? New or NOS?
FWIW, I used to use Tung Sol ri 6V6s in a Z28, and I pushed it hard. 12-18 months was about average replacement time. They would start to not give up the clean tone sparkle, they'd "sound tired." But they never failed.
Amp fired up ok at start of practice but within 15 mins I could tell I was losing power. Also my clean sound had disappeared and it had a low grade drive sound (clean channel) even with gain set really low. I did my best to compensate but it was sounding pretty dire. After 45 mins output minimal and lots of heavy static sounds so turned it off.
I have some new Mesa 6L6GCs and so I will swap them out tomorrow and run the amp for a couple of hours to settle them in. Hopefully that will fix it for now.
But as previous posters have said, short tube life is a bit of a worry. Mind you, the long running Mesa tubes I have are 12AX7s and EL84s. None of the 6L6GCs have lasted for long periods of time (over 3 years etc) I’ve had The amp since 04.
Whatever happened to the new US made 6L6GCs that were back on the market a few years back? Mesa Gold label or something.
RCA? GE? Pretty much foreverA pair of 6L6GC's can easily last for decades. I've had many pairs that lasted 25+ years.
Amp fired up ok at start of practice but within 15 mins I could tell I was losing power. Also my clean sound had disappeared and it had a low grade drive sound (clean channel) even with gain set really low. I did my best to compensate but it was sounding pretty dire. After 45 mins output minimal and lots of heavy static sounds so turned it off.
I have some new Mesa 6L6GCs and so I will swap them out tomorrow and run the amp for a couple of hours to settle them in. Hopefully that will fix it for now.
But as previous posters have said, short tube life is a bit of a worry. Mind you, the long running Mesa tubes I have are 12AX7s and EL84s. None of the 6L6GCs have lasted for long periods of time (over 3 years etc) I’ve had The amp since 04.
Whatever happened to the new US made 6L6GCs that were back on the market a few years back? Mesa Gold label or something.
Thanks for detailed advice! Not easy finding a good tech where I live but probably long overdue.Ime and imho, whenever an amp’s sonics change....even if the amp starts to sound fantastic compared to just good...the player needs to immediately take a look at the power tubes. If there is any redplating, shut the amp down. If no tubes are redplating, there is something wrong in the Biasing or power supply. If only one Tube is redplating, then there is a problem with that tube or the circuit associated with that tube. If there is no redplating, then a ‘ touch’ test can be done.....shade tree mechanic kind of thing. One should be able to touch a power tube for part of a second without any severe burning. If one tube is cooler than the other tube/s, then that tube is not conducting current and the sonics will suffer.
In any case, it is not advisable to continue to play the amp....more severe damage can be done. In your case, Southpole,
I would advise you NOT to retune and fire that amp up. IMHO, it is tech time. A tech will pull that chassis and survey the situation before installing tubes and firing the amp up. Again....continued operation or ill-advised ‘testing’ with other tubes may lead to more severe damage...and expense. My fingers are crossed for the well-being of the transformers in that amp.