TUBE LIFE....

I bought a used MKV about 4 years ago and was pretty thrilled with it. (duh!) After many hours (in years) of using it I started to dislike the tone. After trying many "tone" altering pedals, pups, settings etc. my brain woke up and decided to change tubes. I started with new power tubes. That was it. I only bought the 4 6L6's so far but it sounds like a brand new amp. Full, fat, clear tone and silent as can be. In my mind, if a tube wasn't obviously bad, they were fine....NOT! One more time... DUH !!
So to anyone who has an old(ish) amp like me...make sure the tubes aren't simply worn and tired. I don't think this was a coincidence.... I now can't wait to get the pre amp tubes put in. I can't believe I waited so long...... :shock:

Power tubes wear with use - and with current production tubes we recommend changing them every 1.5 - 2 years (and whenever you obtain a used amp). Sure, you can wait longer - but its like changing the oil in your car....you can push it, but the engine will suffer and your chance of failure goes up.

Preamp tubes are a different story. They don't wear the same way power tubes do - and can last much, much longer. I recommend taking one new 12AX7 and swapping it through each position, one position at a time. If you don't hear any change in a particular position, put the tube that was there back and move to the next position. If you find that a certain position sounds different or clears up a noise/signal issue - you've pinpointed the tube that needs to be changed, without removing perfectly good preamp tubes.

Rectifier tubes are either working or not. They really only need to be changed when they fail.

Hope this helps.

This is good information^^ the other day I turned on my Mark V and thought it sounded flat and I've noticed the 80hz slider creeping up and it's now maxed out and doesn't have that low end like it used to. I've had this amp going on four years with the same tubes. Also notice a little bit of noise with guitar volume on zero. So maybe it's time for a new set of power tubes.

THANKS ! Mr. Authorized Boogie....Grateful for the info... I happened to be near the music store yesterday and bought all new pre and rect tubes. OH well...can't hurt but I did have a tube "incident" yesterday...Here's my newest post describing what happened.

http://forum.grailtone.com/viewtopic.php?f=16&t=71207

I'll bet you can advise us on this topic too...

Thanks in advance

Sadly Mesa doesn't make tubes , all production comes from eastern europe or asia !

even sorted, matched , new production tubes are so weakly produced you can't bet how long it would last , before becoming microphonic or glowing lika bulb!

i personally doesn't buy on reissue 6l6 or even 12ax7 (weaky tone) , when those tunes was made in europe or USA, they lasted forever, its sad to be witness of quality fading so low with expensive new production (new sensor, shughang etc), theyare more eager to look at thier stock market share rates rather than producing something consistant!

sadly russian last reliable manufacturing compagny , SED closed doors of st petersburg plant in 2012. no more Winged C

Wow that is terrible. and it shows with my new tubes...I've now had TWO different tubes "short" out in the first week...Are you saying there's nowhere to get high quality 6L6's? I cannot believe MESA hasn't stuck to high quality stuff...Unless there just aren't any options for their sourcing...I find that hard to believe...
Thanks

There is very little market for tubes, and almost no high-price market. In the old days, companies made military tubes for big $$, and they either sold extra/derated mil tubes for commercial/consumer use, or made consumer tubes on similar lines with similar raw materials.

Now it's all designed for lowest possible cost. If enough people would pay double for tubes, the quality would go up.

Already paying double in Australia. Haha!
But really do you think that more money would be a good enough incentive?

oblivius said:

Wow that is terrible. and it shows with my new tubes...I've now had TWO different tubes "short" out in the first week...Are you saying there's nowhere to get high quality 6L6's? I cannot believe MESA hasn't stuck to high quality stuff...Unless there just aren't any options for their sourcing...I find that hard to believe...
Thanks

Click to expand...

in the 70's they removed graphite from plate , it made black plate grey plate

today i think the removed very of rare metals that once been used in the past!

here is what made tubes lasting , quality,

https://www.youtube.com/watch?v=GDvF89Bh27Y


here the guy talk about not sorted tubes as reissue quality production, and sorted and tested tubes as Mesa boogie balanced triodes tubes, he talks about the PI tube and V1

https://www.youtube.com/watch?v=boGZoURRQ3Y

My theory is balanced tubes (triodes) aren't only needed as PI fonction, All mesa tubes are sorted and balanced to a minimun output, and for me its part of the magic, as most of premium brands in Hifi sort and match all stages transistors pre amps, guitar amps are better in tone with all matched triodes exept overdrive channel witch require most gain!