Mesa Express 5:25 Loss of Power and Definition

[EtherealWidow]

Nice dude. I'm telling you, if you're into absurd amounts of definition, try lower gain tubes in V2 and V3. I kinda wish I could get a little bit more feedback from the amp without lots of treble or gain. I'll find a way though.

 

[FXR]

No, I'm not anal about the definition. But, if you had heard my Express before the fix, you'd understand what I mean, it was mud. You knew the tone sucked the second you hit a note.

When I turned it on with the tube that fixed it, I knew on the first note. Hell, when my wife heard me playing she even commented that the noise was gone and it sounded nice again. There was some sort of mud noise accompanying and ruining every sound that the amp amplified.

I get the idea behind the lower gain tubes. But I'm happy now. I'm staying with the 12ax7 tubes. The NOS JAN 5751, a truely 12ax7 compatible tube, is a 70% gain tube that's in the reverb to tame it a bit. I'm just not big on changing the preamp tubes to 12at and 12au where the circuit wasn't designed for it.

Too much gain was never one of my complaints. During the problem period I couldn't find gain, only mud and then feedback. Now I have gobs swirling gain and subtle distortion that is a treat to work with and play. I'm back in love with my Express 5:25.

 

[FXR]

The Honeymoon is over. My Mesa Express 5:25 sounds like flat again. It's eating tubes, OTs and Pres it seems. There is something wrong with it, it seems. But is it the amp or the tubes seems to be the problem.

 

[FXR]

Tried changing the PI tube again. It got a little louder, but it didn't clean up like the on Nov.30th when I had the Revelation.

I'm, bummed. I've owned this thing over a year and spend a lot of time trying to get it to sound right.

 

[FXR]

I had to give it another shot. I looked in my box and found a Mesa 12ax7, looks like a JJ, they sent me a few weeks back while troubleshooting. It's in the PI now. Seems like the solution, for now.

 

[FXR]

That didn't seem to work out. Seems flat too.

 

[FXR]

At least I tried. The last three days have been amazing. To be right back here again is just so friggin' frustrating!

 

[a2dconverter]

Hey FXR,

It sounds like through all of the constant tube changing you've either fatigued your tube sockets or have tubes that you think are good which are actually bad.

It sounds like the amp was running fine when you received it from the MESA Factory ... then you started messing with tube substitutions.

It also sounds like you're going through output tubes faster than normal..is it possible that you are running Your Master volume very high?

Just put the original tubes back in and be happy!

 

[EtherealWidow]

Hey FXR,

It sounds like through all of the constant tube changing you've either fatigued your tube sockets or have tubes that you think are good which are actually bad.

It sounds like the amp was running fine when you received it from the MESA Factory ... then you started messing with tube substitutions.

It also sounds like you're going through output tubes faster than normal..is it possible that you are running Your Master volume very high?

Just put the original tubes back in and be happy!

Nah man. It couldn't be a tube problem. He tried all kinds of different tubes to fix it. Not only that, but plenty of people have weird cocktails and no problem. There's something seriously wrong with this guy's amp. FXR, it sucks that you found great tone and now the amp is acting up again. Do you think Mesa will still help you out even though you modded it? Hope you can still get a good amp out of this, although you'll probably have a foul taste in your mouth after everything.

 

[FXR]

I replaced the tubes multiple times at the request of Mesa. Mesa supplied preamp and output tubes at their cost. I would not have changed the **** tubes so many times if something didn't do wrong. And a change or two or three developing a "cocktail" should not wear out the sockets. However, a bad PI socket is Plausible based on recent troubleshooting results.

But, Mesa said there is nothing wrong with my amp. I have to assume they inspected the sockets and had the preamp tubes in and out too. Unfortunately, it sounds pretty much the same now as when I sent it to Mesa for the most part.

I didn't mod my amp. I talked to Mesa and Mesa themselves, I have the notes of who when and what time, told me they prefer Mesa tubes, especially in the OT positions, which I have, but that they had no problem with me trying other preamp tubes.

Changing Preamp tubes in not a mod. It's a necessity. Mesa has several pieces of instructional media to teach us how to do it and from talking to Tien, they encourage us to change preamp tubes ourselves.

I don't know what to do. There is a solution, it's just been elusive.

 

[EtherealWidow]

Oh alright. I thought you did the tone bleed mod. Maybe that was Edward. Someone in here did a tone bleed mod. They'll help you out. You still got 4 more years of warranty. The amp will get fixed. It's just a matter of getting the foul, foul taste from your mouth because you got a 1 in 1,000 dud of an amplifier. You know Mesa is a good company. You know it's a good amp. You'll fall back in love with it, but your wife will probably hate Mesa forever. :lol:

 

[FXR]

Oh alright. I thought you did the tone bleed mod. Maybe that was Edward. Someone in here did a tone bleed mod. They'll help you out. You still got 4 more years of warranty. The amp will get fixed. It's just a matter of getting the foul, foul taste from your mouth because you got a 1 in 1,000 dud of an amplifier. You know Mesa is a good company. You know it's a good amp. You'll fall back in love with it, but your wife will probably hate Mesa forever. :lol:

Yeah, she's not happy right now. We went from three days of playing actually music after weeks of , what does this sound like, back to why does this noise happen.

I'm going to the jam, but I feel the amp is off somehow. It sounds half off, the volume is down and the gain knob is pretty difficult to work with past 12 o'clock again and makes mud, not gain. The difference in volume from 5 watt mode to 25 watt mode is tone, not volume for the most part.

See ya later, I'm going to go try and enjoy myself. Even if I have to play a Behringer solid state to do it, sadly. One of my buds does R&D with Line 6. He's pretty objective though. I'm going to get him to plug in and take a listen. He'll be honest, he won't just say get rid of it and get a Line 6. He's actually a Mesa fan too.

 

[FXR]

So, the jam went well.

The line 6 guy had some modeling pedal board thing and was distracted. But, another good friend and musician showed up. He's like can I play the Mesa? I'm like sure, but it's been acting strange burning down tubes. He's like yeah, these things usually push the front end so hard you can burn down tubes. But hey, let's see what she can sound like. He gets the clean channel going with gain pushed to about 3 o'clock and does some tone stack settings. Bam, loud as hell and full of life.

Cool. But will it last? Yeah, it did last the show.

So, he later switches to the gain channel and uses it pretty much the way I had it set, cool.

Another Mesa user arrives, without his. Says, hey man, let me use your Mesa. I'm like sure but, yada yada, clean channel seems good, gain channel might need tweaking for you. So he does his thing and jams out an amazing set.

The amp performed. It performed well. But, I still had that but but but in the back of my head. My sets went great too though despite that. In fact, I had to turn down and could still hear my amp without going to the monitors.

Let's see what happens going forward. The first PI tube to go was the original Mesa tube the amp came with. The Second was an EH. The one in there now is a Mesa, looks like a JJ, and is working. It's pretty hot though. The other night It was late, I still had the gain hot, I probably had ear fatigue, I was certainly frustrated, and today jam went well and I had fun playing.

So, I'm watching the PI tube. Let's see what happens. I see a lot of talk about SPAX Mesa tubes. Maybe I need one there? I think we're zero'd in on something. I hope it's a means to an end of finding out for certain and getting back to playing without something of a question looming in my mind.

She loves, me. She love me not. She loves me. For now.

 

[FXR]

Could I have been just playing too loud? In perspective tonight after a live jam, I'm thinking it could be a contributing factor perhaps.

Anyway, it's running really nice in 5 watt mode tonight and I'm enjoying it.

Oh yeah, and I forgot to mention, my friend that uses Mesa scolded me for using the Bad Money gain. He said, use the pedal, but for volume and tone only for a little volume boost. Let the real tubes do the gain.

 

[EtherealWidow]

I dunno dude. If it lost power it may be something else. I'm telling you though. All 12AX7's make for some nasty compression IMO. I throw the 12AU7's in the V2 and V3. Suhweet.

 

[FXR]

Thanks for the replies if I have not said so yet, EW.

I dunno if I need to do that. But it looks like something that tames the front end and allows you to run the output end more open?

I was playing loud. Louder then stage loud it seems. I'm in perspective again. The amp with the Mesa tube is working great.

The sounds are nice. I've beed playing along with blues radio on comcast for about 3 hours now having fun. I'm in 5 watt mode.

1: Clean. 3 - 11 - 10:30 - 10:30 - 9 - 10:30 Contour at 3, switchable.
2: Burn 11 - 12:30 - 1 - 11 - 7:30 - 9:30 Contour at 12, switchable.

All those are in o'clock. I'm playing my Stratocaster on 6.

In front is a bad monkey. It's set volume 100%, bass at 12 o'clock, Trebble at 12 o'clock, gain off. It adds a nice litlle volume boost for leads on both channels without chaging the tone.

 

[Don]

If your problem comes back, take a look at the leads running from the PCB to the potentiometers (if you know how to work safley within an amp).

The lead to the mid potentiometer on channel 2 on my Express 5:50 was not soldered! The amp intermittently sounded really flat on that channel. Finally I noticed that my mid control did nothing and if I tunred down the treble and bass controls with the mid control dimed the amp made no noise!

It was an easy fix to a tough to find problem!

I have also had to replace the PI tune on this amp. It seemed like only half of the tube failed. The amp still worked well in the 5 watt mode!

 

[EtherealWidow]

Ah no prob, man. That's exactly what this forum is for. And the super low gain pre tubes don't necessarily allow you to run the power amp more open, because there's ultimately a lot less signal going to it, so you're probably not going to get as much power tube distortion in the long run, but for me, everything was a plus with the little experiment. I'm going to be recording in an apartment so the low volume, high articulation, great tone aspect is really the best. I just can't go back to that old tone. I tried with the AX back in the V3 position and everything just went to hell.

And about your amp: I hate to be a skeptic, but I wouldn't trust your amp again just yet. With all the trouble it gave you, I'd still keep my eye on it. If it acts up again, I'd say just give it back to Mesa and get a new amp. Let them sort it out. You've had enough trouble. Glad you're enjoying it again though. They're really great amps.

Also, is it just me, or has this problem been really prevalent lately? Seriously, like at least 2 other people have posted a thread about this! It always makes me nervous. Makes me feel like I'm next in line.

 

[FXR]

Ah no prob, man. That's exactly what this forum is for. And the super low gain pre tubes don't necessarily allow you to run the power amp more open, because there's ultimately a lot less signal going to it, so you're probably not going to get as much power tube distortion in the long run, but for me, everything was a plus with the little experiment. I'm going to be recording in an apartment so the low volume, high articulation, great tone aspect is really the best. I just can't go back to that old tone. I tried with the AX back in the V3 position and everything just went to hell.

And about your amp: I hate to be a skeptic, but I wouldn't trust your amp again just yet. With all the trouble it gave you, I'd still keep my eye on it. If it acts up again, I'd say just give it back to Mesa and get a new amp. Let them sort it out. You've had enough trouble. Glad you're enjoying it again though. They're really great amps.

Also, is it just me, or has this problem been really prevalent lately? Seriously, like at least 2 other people have posted a thread about this! It always makes me nervous. Makes me feel like I'm next in line.

You took the words out of my mouth. Too many express users have sound problems. I'm glad it's being noticed. But, I wouldn't mind being wrong. It could come down to tubes. But, is it tubes dying or the circuit wearing them out quickly? That's where we are right now IMO. I mean ****, I had 4 days of absolute bliss.

 

[FXR]

Oh alright. I thought you did the tone bleed mod. Maybe that was Edward. Someone in here did a tone bleed mod.

I do have the treble bleed mod on my strat. Maybe I had mentioned that?