HELP! Lone Star 1x12:ringing/buzzing noise only on one note.

[DoTheDo]

Whenever I hit an 'F#' note on 5th string at 9th fret I get a ringing/buzzing sound coming from the speaker. Could this be something loose inside the amp on the board? I've taken the casing off and did a visual. Couldn't see anything loose. Suggestions would be very helpful at this point.
Figures.....I have gig in two days. Not sure if this amp is stage worthy at this point.

 

[zeppman]

It may be a tube rattle, I have had tubes that would rattle only on certain notes before. I don't remember what the specific name is, but it has to do with hitting a note that is at or close to a certain "resonate" frequency that cause that certain object to rattle, in this case the tube.

 

[Kyle]

I know this sounds weird but take your foot or something and put pressure on the front of your amp at or around the MESA logo, just below the tone knobs and see if it stops. If so, there is a screw that was put in too tight and the head was stripped off. I had similar problem with my LSS when hitting certain notes. To fix, you have to take a couple of self tapping screws and better secure the board that the speaker mounts to with the front panel. This fixed my problem. Let me know if you need further details.

 

[DoTheDo]

I know this sounds weird but take your foot or something and put pressure on the front of your amp at or around the MESA logo, just below the tone knobs and see if it stops. If so, there is a screw that was put in too tight and the head was stripped off. I had similar problem with my LSS when hitting certain notes. To fix, you have to take a couple of self tapping screws and better secure the board that the speaker mounts to with the front panel. This fixed my problem. Let me know if you need further details.

Thanks for the tip. I'm at work right now so I can't try your suggestion but will do so when I get home. If this isn't the fix...any other suggestions? What about preamp tubes? Could one of the tubes be faulty.

(you may have read my earlier post) I'm also having a problem when switching from channel 2 to 1 where the reverb delay makes a loud sound and fades out. It's fine going from c1 to 2. Although the amp was a floor model it's still under warranty. So I'm going to pick a set of preamp tubes and try replacing them. Does anyone happen to have the Lone Star Classic's tube chart handy?

 

[zeppman]

Here is the link to your manual

http://www.mesaboogie.com/manuals/user_manuals.htm

 

[DoTheDo]

Here is the link to your manual

http://www.mesaboogie.com/manuals/user_manuals.htm

Thanks zeppman. Alas...there's no tube chart in the manual. I was going to stop by the music store on the way home to pick up the tubes. I know there are 5 preamp tubes...just not sure which they are.

 

[Timbre Wolf]

Hey DoTheDo - I've had the same problem with one of my M/B 1x12 widebody cabinets. Get this: it was with the same note! It turned out to be a slightly loose speaker screw. At least I think it was a speaker screw - the solution was to tighten all speaker and cabinet screws. Seems they work loose with all those vibes, and that F# must be the resonant frequency of the cabinet. Try it, and report back.

'Course, if the screw was stripped, as Kyle noted, it would cause the same kind of loose-fit problem. Lotsa luck!

 

[DoTheDo]

Hey DoTheDo - I've had the same problem with one of my M/B 1x12 widebody cabinets. Get this: it was with the same note! It turned out to be a slightly loose speaker screw. At least I think it was a speaker screw - the solution was to tighten all speaker and cabinet screws. Seems they work loose with all those vibes, and that F# must be the resonant frequency of the cabinet. Try it, and report back.

'Course, if the screw was stripped, as Kyle noted, it would cause the same kind of loose-fit problem. Lotsa luck!

Thanks Timbre Wolf. The sound vibration I'm experiencing when I hit that F# seems to be coming out of the speaker as opposed to any type of wood/enclosure vibration. It sounds like a ringing, very bell like high pitch vibrating. Nonetheless, I'll recheck all the speaker screws and those holding the cab together to make sure they aren't loose. I wouldn't be too concerned by this but since I have a gig on Wednesday night and need to get this amp stage ready. The reason I bought the Lone Star in the first place was to replace my Fender Twin (which died on me during the last set of a gig a couple of weeks ago).

 

[Surfcaster]

I also had a tube do that to me once...on an Ampeg Reverberocket. It had this sound like a BB rolling around in a tin can, sort of. An amp guru friend of mine had me doing all these checks to make sure it wasn't my speaker going bad, and before long I was certain it wasn't the speaker and I had double and triple checked everything on the amp that could possible be loose. Finally realized it was a tube. Eventually got an extension cab then no problem (and got a better speaker in the process). Anyway, it could be any number of things. And since you're only hearing it on one frequency, it seems very likely that it's just something that's loose and physically vibrating at it's resonant frequency, as someone said earlier. It's just a matter of locating it.

 

[zeppman]

If you still think it is a tube, they should all be 12ax7 types. Just pull a tube and check though, it will be written on there.

 

[DoTheDo]

If you still think it is a tube, they should all be 12ax7 types. Just pull a tube and check though, it will be written on there.

Just checked the tubes. They are 12AX7s.

The noise coming out of the speaker sounds just like the rings on a tamborine. Again, it's only audible when I hit an F# note anywhere on the fretboard.

If anyone else has any suggestions on what the problem could be, please chime in. ;-)

 

[Kyle]

After reading your previous post on reverb issue, if possible, i would take it back to the store you got it from and get another one. Sounds like trouble brewing. I wouldn't risk my gig with it. I know on the LSS, if you have very different power settings for channel 1 and 2, you will get a noticeable pop when switching channels, regardless if reverb is on or not, but this doesn't sound like you're problem. I would advise, "take it back and get another one before your gig".

 

[Timbre Wolf]

So I guess the screws are all tightened down, on the speaker then? The reason I ask is that I was also convinced that it was a speaker problem (sounds like it's coming from the speaker because it is coming from the edge of the slightly loose speaker) when this happened to me. I was about ready to ship the speaker off for repair.

If you haven't checked the screws around the speaker, I'd say try that...

 

[DoTheDo]

After reading your previous post on reverb issue, if possible, i would take it back to the store you got it from and get another one. Sounds like trouble brewing. I wouldn't risk my gig with it. I know on the LSS, if you have very different power settings for channel 1 and 2, you will get a noticeable pop when switching channels, regardless if reverb is on or not, but this doesn't sound like you're problem. I would advise, "take it back and get another one before your gig".

The LS that I have was a floor model. I purchased it at a reduce price but discovered the reverb problem (and now the noise problem). So, I decided to purchase a new amp and have since ordered it, but
it takes 4 - 6 weeks to get one from Mesa. The store has no others in stock. In the meatime I've got this amp, not too worried about the reverb issue (I'll keep it on channel 1 and use a tube screemer for overdrive). But the noise thing is driving me nuts. I'd like to try to troubleshoot that myself. After my gig on Wednesday I'll take the amp back and wait for the new one to arrive.

 

[Kyle]

After insuring that the speaker is secure, like another posted here,and if you're up to it, I would take two black self tapping screws of the right length, and from the back, drive them in left and right of center, making sure you secure that front panel to the speaker panel. Don't overtighten or the head will strip off. Just make sure they are flush and tight. I know, because I stripped a couple! You will have to remove the amp chasis from the cab to do this. When I checked my amp, there were no loose screws but I did it anyway and it solved my problem. I hope it solves yours. Good Luck!

 

[Surfcaster]

It's fine that you're getting a replacement, probably a good move in the long run. However, I still suspect it could be mechanical noise in a tube, but if it's mechanical noise, it's more likely to be a power tube than a pre-amp tube (that was the case with my Ampeg), so looking at your 12ax7s won't help. But even looking at the 6L6s probably won't help either, it's unlikely you can SEE anything.

Here's a way to find out it the culprit is a power tube or not. Take one 6L6 out and try the amp (the manual says that running the amp with one tube missing for just a short time will not harm the amp). If you still hear the noise, put that tube back in and take out the one next to it, and so on down the line. If the noise is not present with one tube out, you know that tube is the culprit...if it's present every time no matter which tube is out, then you know it's something other than a tube...or I guess it could be multiple tubes!! :? Anyway, I think it'd be worth trying.

 

[zeppman]

Or you can go through and tap each with a pencil.

 

[DoTheDo]

Or you can go through and tap each with a pencil.

I've tapped the pre-amp tubes with a pencil. didn't hear anything such as the noise I get when I hit that f#. I picked up 5 new 12XA7 preamp tubes today - will try replacing them tonight when I get home. Someone mentioned it could be a power tube as well? If that's the case I may need another trip back to the music store. What really pisses me off is that I have a gig tomorrow night..this couldn't be happening at a worse time.

Anyway, I really appreciate the help I'm getting here on the Boogie Board. Thanks guys!

 

[DoTheDo]

What's the safest way to trouble shoot the tubes? Do I need to turn the amp completely off each time I exchange a tube. Then power it back on or can simply switch it to standby swap the tube, try it then elimate the bad one? Of course I'll need to repaert this 5 times for each of the 12XA7s. Unless I find the bad one right away. [/i]

 

[zeppman]

If the noise comes out of the speaker on every channel, it could be a power tube or V1. If its just the 2nd channel, it would be the power tubes, V1, or V2. If its the 3rd, it could V1, V2, or V3 and the power tubes. I don't think the phase inverter would cause an audible problem as you have described, or V5 for that matter... As far as swapping tubes with the power on... i believe.... (check the manual because I think I remember reading it there) that you can pull one power tube at a time while in stand by, if only for a very short period of time. Same what surfcaster said. But check the manual. I don't know if this rule covers pre-amp tubes. When trouble shooting keep this in mind. Power tubes and the phase inverter (V4) will affect all channels. V1, V2, V3 pre-amps correspond to each Ch 1, 2, 3... BUT: Channel 3 uses V1, V2, V3 (cascading gain stages) and Channel 2 uses V1, V2... and so on.

My overall suggestion would be that if you are taking this amp back to the store, don't spend your own money on tubes. Suggest to the store that if they plan on trying to sell this item, they are probably gonna have to retube it, and maybe they should just supply a whole new set for you for now so you can use it. You are their customer, and you are spending a good chunk of money. Its not like this is a $100 practice amp...