Issue with Express 5:25

[rdm]

Been having an issue with my Express 5:25 over the past 48 hours. I've been trying to really dial in a decent tone on the Blues/Burn channel. It's been really harsh/ice picky, so I've been doing lots of toying with the EQ. The pups in my Strat area a bit bright by nature, but I've found myself running that channel with the Treble turned down fairly low....MUCH lower than the Treble on the clean channel.

Last night while I was practicing at home, the burn channel just sounded bad. It was really farty....almost like a blown speaker. Clean channel was fine, even with some OD. I set a tuner down on the top of my amp and instantly heard some weird "chime" type of sound. I turned the amp off, and after letting it cool down, I checked the tubes to make sure they were all seated properly. Everything seemed fine, and when I turned it back on, it was like a new amp. No issues.

Ran the amp at church today, and when the amp was mic'd and I was listening through my in-ears, I was able to hear a high-pitched tone...similar to that of a test tone. Not like a squeal or anything....but a solid tone. It wasn't feedback. When I changed to the clean channel the sound would disappear. It eventually stopped....then returned a few hours later.

This amp was a floor model at a GC, and it was at a store where I used to work...and my buddy I got it from would have told me if there was any issues. I figure I can call up Guitar Center and have them order me another one since I just got this last weekend....or deal with Mesa direct.

In the meantime....what should I look for/troubleshoot on my own before calling either Mesa or GC? Out of all my years playing through tube amps, I've never seen/heard this before.

 

[rdm]

Or...I might just return it and get the 1x12 instead

 

[soundchaser59]

What tubes are in it? I was told that there is a huge problem with the tubes that Mesa puts in at the factory getting removed at the store and replaced with more common, lesser brands.......just a rumour I heard from an amp tech at a dealer.......but coming from GC, who knows. It's really the only thing you can change and test to try and fix the problem yourself. But the 1x12 trade would be mighty tempting.

Just remember one thing if you decide to deal with Mesa direct.......another rumour I've heard is they can void the warranty if the amp does not have Mesa's stock tubes in it. Is that true?

Why is it so many people who report problems with new amps, even with new Mesa's, say they bought the amp at GC?

 

[rdm]

What tubes are in it? I was told that there is a huge problem with the tubes that Mesa puts in at the factory getting removed at the store and replaced with more common, lesser brands.......just a rumour I heard from an amp tech at a dealer.......but coming from GC, who knows. It's really the only thing you can change and test to try and fix the problem yourself. But the 1x12 trade would be mighty tempting.

Just remember one thing if you decide to deal with Mesa direct.......another rumour I've heard is they can void the warranty if the amp does not have Mesa's stock tubes in it. Is that true?

Why is it so many people who report problems with new amps, even with new Mesa's, say they bought the amp at GC?

Stock tubes. I can't speak for ever Boogie dealer, but having been a manager at GC, I can say that the chances of a sales guy pulling tubes from Boogies and dropping in another brand is most likely not going to happen.....but who knows.

Anyway...I'm going to make the change from a 1x10 to 1x12 and just let GC deal with the amp.

 

[Newysurfer]

Been having an issue with my Express 5:25 over the past 48 hours. I've been trying to really dial in a decent tone on the Blues/Burn channel. It's been really harsh/ice picky, so I've been doing lots of toying with the EQ. The pups in my Strat area a bit bright by nature, but I've found myself running that channel with the Treble turned down fairly low....MUCH lower than the Treble on the clean channel.

Last night while I was practicing at home, the burn channel just sounded bad. It was really farty....almost like a blown speaker. Clean channel was fine, even with some OD. I set a tuner down on the top of my amp and instantly heard some weird "chime" type of sound. I turned the amp off, and after letting it cool down, I checked the tubes to make sure they were all seated properly. Everything seemed fine, and when I turned it back on, it was like a new amp. No issues.

Ran the amp at church today, and when the amp was mic'd and I was listening through my in-ears, I was able to hear a high-pitched tone...similar to that of a test tone. Not like a squeal or anything....but a solid tone. It wasn't feedback. When I changed to the clean channel the sound would disappear. It eventually stopped....then returned a few hours later.

This amp was a floor model at a GC, and it was at a store where I used to work...and my buddy I got it from would have told me if there was any issues. I figure I can call up Guitar Center and have them order me another one since I just got this last weekend....or deal with Mesa direct.

In the meantime....what should I look for/troubleshoot on my own before calling either Mesa or GC? Out of all my years playing through tube amps, I've never seen/heard this before.

Sounds like a tube or other amp malfunction to me.
No Mesa amps sound like that when working properly.
And Mesa do use very ordinary Chinese tubes stock so if any store swapped em out it would probably improve it.
The 1x12 sounds better anyway so I'd go for that if you don't mind paying a bit more $$ :mrgreen:

 

[soundchaser59]

I bought my Express from a locally owned dealer in Omaha. It supposedly came directly from Mesa, but it had JJ, GT, EH, and Sovtek tubes in it when I got inside it. I believe Mesa when they tell me they would never send any amp out from the factory with that wide selection of tubes in it. The store would not say anything specific about my amp, but they did say they sometimes change tubes in new amps if they have reason to suspect a tube is defective. So why did mine have all 5 tubes replaced? I imagine Mesa will ask them the same question. I seriously doubt it had 5 defective Mesa tubes in it when the store got it.

If the local family owned dealer did that, who knows what other big chain retailers might have going on.......

I just thought of it because the symptom you described reminded me of microphonics and tube problems. The only way I got rid of the microphonics in my Express was to put all new 12AX7's in every slot. I found that just one lower gain tube in any of the first 3 slots would give me symptoms similar to yours. Same thing with some NOS black plates I tried, probably due to the mismatch in gain? I have four 5751's in it now, same gain in all slots, and have no symptoms at all.....just sweet tone.

 

[Newysurfer]

I bought my Express from a locally owned dealer in Omaha. It supposedly came directly from Mesa, but it had JJ, GT, EH, and Sovtek tubes in it when I got inside it. I believe Mesa when they tell me they would never send any amp out from the factory with that wide selection of tubes in it. The store would not say anything specific about my amp, but they did say they sometimes change tubes in new amps if they have reason to suspect a tube is defective. So why did mine have all 5 tubes replaced? I imagine Mesa will ask them the same question. I seriously doubt it had 5 defective Mesa tubes in it when the store got it.

If the local family owned dealer did that, who knows what other big chain retailers might have going on.......

I just thought of it because the symptom you described reminded me of microphonics and tube problems. The only way I got rid of the microphonics in my Express was to put all new 12AX7's in every slot. I found that just one lower gain tube in any of the first 3 slots would give me symptoms similar to yours. Same thing with some NOS black plates I tried, probably due to the mismatch in gain? I have four 5751's in it now, same gain in all slots, and have no symptoms at all.....just sweet tone.

Soundchaser - the store definitely changed tubes in your Express. Consider yourself lucky - they sound like much better tubes to me. All stock Mesas come with factory fitted Chinese tubes and the only marking is a Mesa logo on them. The Mesa tubes are not top quality, they're not crap either just ordinary Chinese quality one's. Mesa claim they're very reliable/durable and they test em all out etc etc which may be true but there's much better quality tubes around and supplers like Dougs and Eurotubes pre test every tube they sell anyway.

Your store must have had a reason to change the tubes. No incentive for anyone to do it otherwise :mrgreen:

 

[espresso]

Aren't 99% of tubes made either in Russia or China?

 

[mlabbee]

sounds like a preamp tube issue - I'd trade out the burn channel tubes and see if it solves it before trading it in (unless you really want the 12")

 

[soundchaser59]

Your store must have had a reason to change the tubes.

The only thing I never figured out is why they put a ECC82 (20% gain) in the P.I. slot. Sounded good, but much lower volume coming out of the speaker. Maybe they did it to make the amp more "palatable" for the show room floor? I figured somebody knew what they were doing because that is the one tube a guy would change to keep the basic tone the same while making the speaker volume more tolerable. I put a 12AX7 in there and the sound was suddenly much much bigger! The P.I. slot is also the only slot where I could put a low gain tube without inducing any unwanted distortion or microphonics. A 12AT7 works just as well in that position, but the 5751's seem to have the best control of the sound while keeping the tone controls clean and tight.

 

[MrMarkIII]

Your store must have had a reason to change the tubes.

The only thing I never figured out is why they put a ECC82 (20% gain) in the P.I. slot. Sounded good, but much lower volume coming out of the speaker. Maybe they did it to make the amp more "palatable" for the show room floor? I figured somebody knew what they were doing because that is the one tube a guy would change to keep the basic tone the same while making the speaker volume more tolerable. I put a 12AX7 in there and the sound was suddenly much much bigger! The P.I. slot is also the only slot where I could put a low gain tube without inducing any unwanted distortion or microphonics. A 12AT7 works just as well in that position, but the 5751's seem to have the best control of the sound while keeping the tone controls clean and tight.

Hey, someone at the store changed the tubes. Mesa amps come from the factory with Mesa tubes. Period.

 

[Dolebludger]

If I had bought a Mesa amp new and found that it had a variety of non-Mesa tubes in it, I would return it to the store and demand that all tubes be replaced with Mesa tubes. Mesa is very clear about the importance of using only Mesa tubes, and the fact that their new amps are equipped with them. Regardless of whoever changed the tubes, you did not get what you paid for, and the retailer is under a duty to correct this.

Now, I am not saying that Mesa tubes are the best sounding in the world. But having the dealer give you what you paid for (all Mesa tubes) would get you to the correct "base point" in the sound of your amp. From there, you can more accurately identify any further tone improvements you may want, do your research, and act accordingly. This may or may not involve a few different brand tubes strategically placed. Now, you have a "mish mash" of tube brands, and this makes it impossible for anybody to tell you what you should do to correct your tonal problem.

 

[UKBoogieboy]

All Mesa boogie valves are Russian according to Mesa Boogie, they are the best, if there was better they would be using them they say in the book.

Also why are peole taking out the mesa boogie valves in the shop????
What sort of criminals work on guitar shops in the USA, that never happens here.

 

[soundchaser59]

Apparently Mesa does jump on them when they hear about it.

I sent a letter to Mesa. A week later I got a box from the retailer with a whole set of brand new Mesa tubes!

The tech guy from Mesa even called me later to make sure I got what I was supposed to get.

Unfortunately, one of the brand new Mesa tubes was dead when I got it. I put all the Mesa tubes in and turned it on, and the blues/burn channel was completely dead. I put a Tung Sol in V2 and the amp came back to brand new life. Put the tube back in just to be sure and the thing went dead again.

So even Mesa tubes are not foolproof...... but a good response to my "complaint"....