I've got a stupid question:

[Micah]

Can anyone explain to me what a power tube would sound like if it is going out or worn? What changes would I notice in the sound of the amp? I have a friend who owns an '81 Mark IIb and he bought it in '86 from a guy and replaced the tubes in it when he bought it and has played the crap out of it the whole time hes owned it--probably @ least 20 hours a week and has never replaced the power tubes in it. Once he had a microphonic preamp tube that was in V1 so he swaped it with V2 and the problem was solved, but he's never replaced any of them but the one time. The thing sounds like a million bucks. I asked him last night if he'd ever thought about replacing them or if he felt like he was missing anything by not changing them and he just said "I like the sound so why screw with it?" I have to say that I sort of agree with him--I mean the thing does sound really good--clear--punchy-clean and dirty channels are both there.. Can anyone tell me what characteristics dwindle away when tubes wear? Over the past 7 years Ive owned 4 different mesa tube amps and I couldnt answer this if someone asked me. The answer I get from most people is that I'll just know when they need replacing..but I have to tell you that I dont...Anyone?

I will say that I do want to swap my EH 12ax7's in the preamp for Tung-sols after all of the great reviews though-- :wink:

 

[musicbox]

As far as I know, you'll get the opposite of what your buddies amp sounds like! A lack of punch and detail. Less dynamics, less goodness. Basically everything you like in an amp gets dulled down. I know from my slowing dying nomad that a different breed of microphonics will show itself(sort of an electric motor whiring) that gets worse or better if you tap the tube.

 

[Micah]

As far as I know, you'll get the opposite of what your buddies amp sounds like! A lack of punch and detail. Less dynamics, less goodness. Basically everything you like in an amp gets dulled down. I know from my slowing dying nomad that a different breed of microphonics will show itself(sort of an electric motor whiring) that gets worse or better if you tap the tube.

I dont get any of that--I have Phillips USA made tubes that they stopped making in the 70's. They must have sat on a shelf for a raelly long time or something--but they came with the amp so I dont know. Im not a big fan of the Electro-Harmonix preamp tubes in it though (I think) if what Im hearing is correct. There isnt as much dynamics in them and they are really fuzzy in the mid-range and top end. I understand that the Tung-sols are supposed to clear this up so Id like to try that, but as far as the power amp tubes, Im not sure I need to change them and its a bundle of money wasted if Im wrong! Thoughts?

 

[RR]

You say its an '81 Mark IIB.

If he claims they're still the original tubes then the 6L6s tubes maybe the Sylvania's 6L6s (MESA's STR-415 if I'm not mistaken). Yes, these tubes will last for a long time and they're the the best 6L6s tubes ever made like Mullards EL34s are the best EL34s.

Of course this is my opinion. This Post should be moved to "Vintage Amps (Before 1991)"

 

[Micah]

You say its an '81 Mark IIB.

If he claims they're still the original tubes then the 6L6s tubes maybe the Sylvania's 6L6s (MESA's STR-415 if I'm not mistaken). Yes, these tubes will last for a long time and they're the the best 6L6s tubes ever made like Mullards EL34s are the best EL34s.

Of course this is my opinion. This Post should be moved to "Vintage Amps (Before 1991)"

They arent the original tubes, they were replaced once in 1986 but they could be those 415's your talking about. Thanks for the info--I was just wondering about 6L6's in general--Mesa says to replace tubes every 1.5 to 2 years and Im not sure if I understand why... In a triple rectifier it would cost me like $120 just for the power amp tubes every year and a half to 2 years and I dont just want to spend that money if I dont have to you know? :?

 

[jbird]

I understand em as being like a light bulb! The more they age, the less they put out! Some old tubes last a long time, I guess? I don't agree with your statement of not wanting to spend the money if you don't have to though! I think having an extra set of tubes is necessity! If not for insurance in the case of back-ups, then for the sake of options for tonal differences! :idea: Try something new you old bat! :lol:

 

[RR]

Micah,

I'm pretty sure they're STR415s because in '86 there weren't too many tube distributors at that time other than Groove Tube and MESAs (well that I know of).

 

[Micah]

I understand em as being like a light bulb! The more they age, the less they put out! Some old tubes last a long time, I guess? I don't agree with your statement of not wanting to spend the money if you don't have to though! I think having an extra set of tubes is necessity! If not for insurance in the case of back-ups, then for the sake of options for tonal differences! :idea: Try something new you old bat! :lol:

I hear you! Id like to buy a second head to sit on top of my Marshall 1960A cab for tonal differences. If Im dumping money into my current head and its not needed then its just pushing that second head further out before I can get it though you know? :?

 

[Micah]

Its funny that I havent had that many replies to this post. Does anyone out there know why they spend $80 to $120 every year and a half to 2 years on retubing the power amp on their rectifiers? Just because someone told them they needed to? :?:

 

[disassembled]

Here's a good analogy:

Tubes=guitar strings

Can you use them for a long time? Yes. Then why should anyone replace their strings unless they break? It's a personal tone thing. Some people replace them bi weekly, some bimonthly, some may even go bi yearly. Who is correct?

Besides, he is going to probably regret the day he turns off standby and gets a strobe like light show from behind the amp and some ruined components. Or who knows, he may never have a problem. If he is not cranking things up (I am talking loud band levels) every time he plays then I don't see a problem with those tubes lasting quite a long time.

I found a huge difference when I changed tubes to a different brand replacing warn old tubes. To me, replacing tubes is just like changing the strings on a guitar. I don't play enough to warrant changing things out more than once every few years. I am, however, very much into trying to prevent any possible headaches in the future from failing components.


I can come up with a bunch of car analogies as well if you'd like

 

[Micah]

Here's a good analogy:

Tubes=guitar strings

Can you use them for a long time? Yes. Then why should anyone replace their strings unless they break? It's a personal tone thing. Some people replace them bi weekly, some bimonthly, some may even go bi yearly. Who is correct?

Besides, he is going to probably regret the day he turns off standby and gets a strobe like light show from behind the amp and some ruined components. Or who knows, he may never have a problem. If he is not cranking things up (I am talking loud band levels) every time he plays then I don't see a problem with those tubes lasting quite a long time.

I found a huge difference when I changed tubes to a different brand replacing warn old tubes. To me, replacing tubes is just like changing the strings on a guitar. I don't play enough to warrant changing things out more than once every few years. I am, however, very much into trying to prevent any possible headaches in the future from failing components.


I can come up with a bunch of car analogies as well if you'd like

Sweet man--I apreciate the input!