Gonna change the tubes in my Mesa Stiletto...

[ratherdashing]

Re: Gonna change the tubes in my Mesa Stiletto...

:grumble:............since when?

Have you ever actually tried a Stiletto?

It crushes any Marshall made since 1990. Easily.

 

[JOLLY]

Re: Gonna change the tubes in my Mesa Stiletto...

Have you ever actually tried a Stiletto?

It crushes any Marshall made since 1990. Easily.

That's your personal opinion. I happen to disagree with it. I'd much rather have my JVM410H over a Stiletto. A buddy of mine had a Stiletto 2x12 combo about a year ago. He eventually got rid of it because it didn't suit his style. It was a great amp, but I didn't really care for it. I'm sure it suits your style fine, just as the JVM suits mine. However, I wouldn't go as far as to say it crushes anything that Marshall has put out since 1990.

 

[FretFire]

Re: Gonna change the tubes in my Mesa Stiletto...

This has always been one of my favorite Stiletto clips.



This one is pretty nice too, totally different flavor.

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

Just finished putting the tubes in the amp. It now has the 5 EHX 12AX7 tubes in the preamp, and the Svetlana =C= EL34s in the power section. Decided to keep the Mesa branded 5U4GB rectifier tube in there, as I don't use tube rectification often, and I was not wanting to spend much more.

The tech at the store says those two kinds of tubes usually match up pretty well. Gonna go try it now.

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

Well boys, looks like I have a problem.

I swap the tubes out, make sure everything is good and in place. I plug the amp in, instantly, the fuse goes.

So I go back to the work table, make sure all the tubes are in properly. Go and plug it back in. It works fine, I get a bit of weird noise out of the tubes, but that goes away really quick. I pass it off as just the tubes settling in.

After about 5 minutes of play, I bring the volume up a bit more, and pow, another fuse goes.

Now, I looked at the power tubes, and they are glowing a little bit brighter than before, but nothing insane. I just put another fuse in, turned it on for a few seconds, and it works just fine.

Anybody have any idea what's going on? If the amp doesn't need to have the bias adjusted, why am I getting these problems?

Help?

 

[FretFire]

Re: Gonna change the tubes in my Mesa Stiletto...

From what I understand, the bias is indeed fixed on Mesa amps but that means you need to make sure you use power tubes that fall within an appropriate range to match. Perhaps the tubes you have in right now are pulling a bit too much voltage?

Note: I fully admit that I'm not up to speed on how Mesa's biasing works, so someone feel free to call shenanigans on this information.

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

So in theory, if I was to pop the Mesa power tubes back in, with the EHX preamp tubes, it shouldn't make a difference, and the cause of my problem is most likely the =C= tubes?

 

[FretFire]

Re: Gonna change the tubes in my Mesa Stiletto...

So in theory, if I was to pop the Mesa power tubes back in, with the EHX preamp tubes, it shouldn't make a difference, and the cause of my problem is most likely the =C= tubes?

I would personally assume so, but I could be wrong.

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

Alright, the Mesa EL34s are back in, but there is a slight blue glow from ''inside'' the metal parts of the tube.

Also when I switch to the distortion channel, there is a ''ping'' that rings out...

I'm confused.

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

Yeah boys, there is a ringing when I'm on the drive channel. Would this be due to a microphonic tube?

 

[ratherdashing]

Re: Gonna change the tubes in my Mesa Stiletto...

Any problem specific to one channel = preamp tube.

Mesa is pretty insistent about using their brand of tubes, mainly because their tolerances are so tight. It's quite possible that one or more of the tubes you bought are outside the tolerance range of the amp.

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

Yeah, just took them out of my amp. That was a failure.

I'll go to the store tomorrow talk to the guy, see if I can return them. Hope this wasn't a massive waste of money.

 

[ratherdashing]

Re: Gonna change the tubes in my Mesa Stiletto...

Yeah, just took them out of my amp. That was a failure.

I'll go to the store tomorrow talk to the guy, see if I can return them. Hope this wasn't a massive waste of money.

Yeah, you could talk to Mesa and see if they know what went wrong, but I'm pretty sure they'll just come back with "you have to use Mesa tubes".

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

Yeah, you could talk to Mesa and see if they know what went wrong, but I'm pretty sure they'll just come back with "you have to use Mesa tubes".

That seems to be the case. I called the guy at the store, he assured me I could just bring the tubes back, and that it's no problem, so at least this mistake didn't cost me anything more than time.

So yeah, the maintenance free bias thing from Mesa isn't as awesome as it sounds. The good news is that their amps do sound really good with stock tubes, so I guess I can't complain that much. The gear whore in me though is kinda sad.

 

[ratherdashing]

Re: Gonna change the tubes in my Mesa Stiletto...

That seems to be the case. I called the guy at the store, he assured me I could just bring the tubes back, and that it's no problem, so at least this mistake didn't cost me anything more than time.

So yeah, the maintenance free bias thing from Mesa isn't as awesome as it sounds. The good news is that their amps do sound really good with stock tubes, so I guess I can't complain that much. The gear whore in me though is kinda sad.

A lot of people misunderstand "maintenance free bias" to mean "you can put anything you want in there and it will work". It actually means "as long as you use our tubes, it's plug and play. Any other tubes: you're on your own." They spell that out pretty clearly in the manual and on their website.

This is not to say that you will NEVER get off-brand tubes to work; there's always a chance that the tubes you pick will be within Mesa's tolerance. There are also tube sellers (such as Eurotubes) that sell sets for Mesa amps that are supposed to be within spec. With those guys, you are not always guaranteed that they know what they're doing, but it's far less of a crap shoot than buying your own off the shelf.

Personally I just avoid the whole problem by buying Mesa tubes. Yeah, they cost more, but not that much. I've never had a Mesa tube die on me, and I never have to deal with any biasing issues, so I'm not upset about having to pay a bit extra.

 

[Gearjoneser]

Re: Gonna change the tubes in my Mesa Stiletto...

A ping noise indicates that it's likely a faulty preamp tube. Put your original pre tubes and new power tube in it, if you have any fuses left.

 

[phil_104]

Re: Gonna change the tubes in my Mesa Stiletto...

A ping noise indicates that it's likely a faulty preamp tube. Put your original pre tubes and new power tube in it, if you have any fuses left.

Yeah, that's what I did. Works fine, sounds exactly like it did before.

Guess I'm just going back to Mesa tubes.

 

[misterwhizzy]

Re: Gonna change the tubes in my Mesa Stiletto...

I understand allowing the bias to be adjusted by techs or users, but rebiasing an amp is a lot of work for very little reward. When you can just pop in a new tube and fire the amp back up, it's a lot more rewarding, because even if it doesn't do what you want, two minutes later, you're back to where you started.

I think Mesa got it right here. Their amps sound great to begin with, and the knobs give you more than enough control over the sound. I think there's a lot more tweaking to be done on the front panel than inside the headshell.

 

[pzaxtl]

Re: Gonna change the tubes in my Mesa Stiletto...

A lot of people misunderstand "maintenance free bias" to mean "you can put anything you want in there and it will work". It actually means "as long as you use our tubes, it's plug and play. Any other tubes: you're on your own." They spell that out pretty clearly in the manual and on their website.

This is not to say that you will NEVER get off-brand tubes to work; there's always a chance that the tubes you pick will be within Mesa's tolerance. There are also tube sellers (such as Eurotubes) that sell sets for Mesa amps that are supposed to be within spec. With those guys, you are not always guaranteed that they know what they're doing, but it's far less of a crap shoot than buying your own off the shelf.

Personally I just avoid the whole problem by buying Mesa tubes. Yeah, they cost more, but not that much. I've never had a Mesa tube die on me, and I never have to deal with any biasing issues, so I'm not upset about having to pay a bit extra.

Of course, as an alternative, you could always swap out the bias resistor, but you'd better know what you're doing if you go that route (read: know more than me!)

 

[Boogie Bill]

Re: Gonna change the tubes in my Mesa Stiletto...

If your amp works with the Mesa tubes and you're not blowing fuses, well...there's your answer: you've got some defective tubes.

If it continues to blow fuses, something is wrong. I'm assuming you're not running the amp wide open; and that you're not using a huge amount of preamp boost into the input.

I would strongly suggest that you call tech support at Mesa Boogie and discuss the problem with them.

One thing to be aware of: as I understand their warranty, if you are using a new amp, under warranty--you automatically VOID the warranty if you use tubes other than the Mesa-branded tubes. You might want to review that warranty, and not mention the tube swap, LOL!

Mesa amps are fixed, non-adjustable bias. As long as you use Mesa tubes, or tubes with the correct characteristics you'll never need to re-bias the amp.

I like the Mesa/Siemens EL34 (and yes they are worth the $$$$); and I like the Winged C EL-34s. The Winged C works very well in high-powered combos. I liked them much better than the EH EL34s.

I''m currently running a set of the Groove Tubes GT-EL-34M Mullard clones in the Simul-Class sockets of my Mark IV 112 EVM combo, with a pair of their GT6L6GEs in the Class AB sockets. The 34Ms are a really nice tube.

Good luck.

Bill