Lonestar Classic crackling - Need help troubleshooting

[R_Rbnsn]

Hey guys,

I've been recording a lot recently using my Lonestar classic but it seems to have developed a problem with crackling. I assume it's probably a tube needs replacing but I was wondering if anyone could help me diagnose what exactly it is.

I've attached a short recording so you can hear what it sounds like, and from all the research I've done so far I can tell you that the crackling is present on both channels.

Here is the recording: https://docs.google.com/file/d/0B4CXWRW-8wOQejAtTmNnNjVKdnc/edit?usp=sharing

I already tried tapping all of the preamp tubes with a pencil to see if I could work out which it was but the tapping didn't seem to induce the noise, instead it's pretty constant regardless. I did also notice that the noise seems a little louder when the "tube rectifier" switch is on the silicone diodes option, but the noise is still present on both selections too.

Thinking it might be the V1 preamp tube (because it's on both channels) I removed them all and moved them all to different slots and that made no difference either. I am also running it on the 50w mode.

Any help would be much appreciated. I would obviously like to locate and verify exactly what the problem is first so I don't needlessly spend loads on new valves I may not need!

Thanks

 

[R_Rbnsn]

Well... after some further experimentation it would seem I've answered my own question.

I swapped the outer 2 power tubes with the inner 2 (as I've been running it in 50 watt mode which only uses the outer 2) and that way round there was no crackling. Swapped it back to confirm and the crackling came back, so it seems I need 2 new power tubes.

Question now is do I shell out for some Mesa tubes or get cheaper JJ's?

PS. I'm also finding it impossible to get the covers back on the preamp tubes. Is there some sort of trick to it? I'm pushing it down and twisting but it doesn't want to go round and just springs off when I let go.

 

[Penguin]

PS. I'm also finding it impossible to get the covers back on the preamp tubes. Is there some sort of trick to it? I'm pushing it down and twisting but it doesn't want to go round and just springs off when I let go.

I find cursing at them while trying to put them back on really helps! Cursing in English, Italian, French and Spanish works well for me. I've also resorted to a few hand gestures, which could also be considered Italian. However, feel free to experiment!

Disclaimer: I am Italian and can speak those languages. No offense implied!

 

[felix vampiro]

Hi there,

R Rbnsn - thanks for posting that. Mine has just started crackling as the note decays so I will try swapping round the output valves.
I have found Svetlana winged Cs 6L6s to be crisper and with slightly more clarity than the Mesa valves. Sound good with strats.

Pre-amp valve covers - you might be pushing down too far.

Cheers

 

[R_Rbnsn]

So, I thought I'd gotten this all sewn up... but today I discovered the amp is still crackling. At the moment I'm still using the "bad tubes" in the middle sockets, but I'm running it in 50w mode so it's only using the outer tubes.

Even so, I discovered it's still crackling (although definitely a lot quieter with the tubes in the different sockets) but more interestingly, it still crackles on both channels but even with their volumes down.

So what could this be?

 

[felix vampiro]

Are you using the combo?
If so, check the speaker lead terminals. I had a persistent crackling which I eventually traced to the solder joint on one speaker terminal which had come apart (probably in the store or in transit), so the end of the lead was vibrating in the terminal and crackling with the intermittent contact.

Might be worth a look.
Cheers

 

[djw]

I had a crackling/popping thing going on with my LSC years ago. Tried tubes and everything I could swap or tweak myself -- ended up taking it in for a repair. I got the amp back with some replaced resistors from somewhere near the end of the signal chain (I honestly forget what they were). Probably need to get your amp to a tech if tubes and cables are ruled out.

Also, re: preamp tube covers: look at the cover, you'll notice there's a channel for a little nub in the socket to fit through and around, like a hook-shaped relief. There's also a small out-dent (sic) on the rim of the cover that lines up with a matching slot in the rim of the socket. Line that up, push the cover over the tube and into the socket, and turn the cover so that the nub in the socket hooks into the little resting spot in the cover. The spring holds it in place once it's twisted over to that point. I believe it's clockwise for on, counter for off. Be sure the tip of the tube goes into the center of the spring in the cover.

 

[Don]

I can't hear your recording but screen resistors can cause the kind of crackling that you're describing. These are 470 ohm resistors connected to pin 4 of the power tubes. Sometimes They're damaged when power tubes fail.

 

[R_Rbnsn]

So after going through all of the troubleshooting methods (including e-mailing back and forth with Mesa) I've finally given in and dropped it off with my tech today. I'll be sure to let you know what it turns out to be.

Just out of curiosity Don & djw, how much roughly was it to get it fixed when the problem was the resistors? Really hoping this won't be expensive!

 

[djw]

Likely depends on the tech. The parts aren't expensive, I don't think. But labor for troubleshooting and repair, etc. could add up. I think my repair cost me about $150 US, maybe a little more. My tech might be on the expensive side too...

 

[BluesAndBooze]

8)
You don't mention if it happens even when instrument unplugged and amp switched on with standby on and whether all channels?!
If it does it is more than likely the carbon resistors in plate load positions of pre-amp tubes (x9). Replace all with metal film types.
Cost me equivalent of $60.
It would also be worth, from the sound of your power valves, getting a new matched quad set, 6L6's or EL34's, stick with Mesa

:mrgreen: Lonestar 100/50w 1x12 6L6 Mesa's loaded with Eminence Commonwealth 12"

 

[R_Rbnsn]

8)
You don't mention if it happens even when instrument unplugged and amp switched on with standby on and whether all channels?!

Yes the crackling is happening even when the guitar is unplugged, but only when the amp is "on"... not when it's on standby. I did mention that it was on both channels in my previous posts (twice in fact!).

 

[BluesAndBooze]

Carbon resistors! Replace all 9 for metal type, they are a natural audiophile upgrade anyway, more reliable and no impact on tonal qualities. This problem is only present when on and plugged in or not. It is not an uncommon problem. Cost me £56 including pickup and return with a 2 day turnaround
Sounds like you've picked up on a power valve problem as well and that's worth a quad swap for what they cost, and might as well do the rectifier valve, these things all tend to age together especially if your running 50w a lot, choice is your taste.
:mrgreen:

 

[R_Rbnsn]

Hey everyone. I finally got my Lonestar back from my tech today, turns out it was just the power valves after all. He's also changed one of the preamp valves too as it was humming a bit.

I've only had a chance to try it out for a few minutes so far but the crackling has definitely gone when I have tried it. The only other thing is he's put EHX 6L6's in there rather than Boogies, but he tells me they're basically all made in the same factory in Russia and the only difference is the logo printed on them. Is that true?

Glad to have it back though, although after having not heard it for 2 weeks playing through the drive channel it sounds too wooly or "like there's a blanket on the speaker" with fresh ears (even with the treble maxed out). Perhaps the time has come to finally take the plunge and do the Reeder mod?

 

[BluesAndBooze]

:shock:
Shouldn't be wooly on channel 2!
Does it vary with drive selector settings? Have you tried it without drive? Should not need to max out treble!
A couple of quick DIY checks are put settings on both channels identical without any drive on channel 2 and compare, you should only have a difference in gain even when gain settings are the same.
Try a preamp valve switch, 1st swap around V1 & V2 and then compare sound as above, then return them to how they were and swap V1 with V3 and compare as above, then return them to how they were. Swap V2 with V3 and compare. You can run that swap test through all five always returning to original valve layout and note which, if any, valve change corrects your problem.
It's an easy check, don't bother putting the metal jackets back on each time, use standby for each switch around.
Does it happen irrespective of watts selection and power mode, I wouldn't suspect the EHX, but why not replaced with Mesa.
:mrgreen:

 

[R_Rbnsn]

:shock:
Shouldn't be wooly on channel 2!

Okay, I might have been exaggerating slightly about it being 'wooly', but after 2 weeks of being without it and playing nothing but Marshalls channel 2 definitely sounds very mid-rangey and lacking in clarity.

I'm sure it's no different to how it sounded before the new valves (minus crackling of course) but with fresh ears I think it's definitely time to try out the Reeder mod.

 

[BluesAndBooze]

Hey everyone. I finally got my Lonestar back from my tech today, turns out it was just the power valves after all. He's also changed one of the preamp valves too as it was humming a bit.

I've only had a chance to try it out for a few minutes so far but the crackling has definitely gone when I have tried it. The only other thing is he's put EHX 6L6's in there rather than Boogies, but he tells me they're basically all made in the same factory in Russia and the only difference is the logo printed on them. Is that true?

Glad to have it back though, although after having not heard it for 2 weeks playing through the drive channel it sounds too wooly or "like there's a blanket on the speaker" with fresh ears (even with the treble maxed out). Perhaps the time has come to finally take the plunge and do the Reeder mod?

:evil:
They're not basically all the same!! Did the tech check the voltage output of the EHX 6L6's to ensure they meet the requirements of the nonadjustable bias Boogie.
Incorrect voltage, too cold or too hot, can result in anything from poor wooly sound to burnout :!: