Crackling Noise

[Talus]

So recently my Mark has been making a crackling noise, it started off as fairly intermittent but has become fairly constant. It doesn't really matter what channel I'm on and will happen even if the guitar and FX loop aren't plugged in.

The only thing that seems to make a difference is Variac power. It still happens, but it's much quieter and less frequent.

I'm assuming it's a tube problem, but preamp? Power? Something completely different? If anyone's got any ideas it'd be greatly appreciated, especially if it can save me from having to spend a ton on tubes.

I took a short recording just to give people a better idea.

http://soundcloud.com/icronic/mark-v-crackle

Thanks

 

[boogieman60]

Do the Tube Tap Test. turn the amp on.. take off standby and with a pencil tap the tubes one at a time. If it is a bad tube, when you find the culprit the noise will get worse.

 

[zakkselvagem]

sounds like a bad cable or bad input in your guitar... just make sure you checked that first.

 

[jb's 52]

sounds like a bad cable or bad input in your guitar... just make sure you checked that first.

+1

 

[flyfisherx]

I have the same issue with mine. Brand new out of the box. It is only on startup when I switch the standby switch to on. It goes away in a minute or so. I am thinking that the tubes are warming up since it goes away in a minute or so of full power. I hope anyway..... Definitely not a bad cable since it does this with nothing plugged into the input.

 

[Stoneyman]

Mine did it right out of the box too. I even called Mesa about it and they told me to replace the V1. I did and it still does it. I checked and replaced cables as my first try and then did the pencil tap test. No luck.

However, I have found that if you let the tubes warm up for about 5 minutes befor playing it works without the noise. From what I can tell its a tube issue, but Im not sure whats causing it.

 

[thalweg]

Same experience here. Happens intermittently. Exact same sound you recorded. Less often when the amp is warmed up. Did some tube swapping a few months back and don't recall noticing it again. Can't remember which tubes I swapped but V7 and V1 for sure.

 

[cherbst]

Definately sounds like a preamp tube, had the same on a new Mark V, called Mesa and they told me the same. Replaced each tube one at a time and found V2 to be the culprit. Didn't make sense since it's not in the path for all channels, but replacing that cured it.

Just be sure to do *one at a time,* and if it's not fixed put back the tube you took out. Don't replace them all or mix them up, all tubes are a little noisy and they are selected to give the best performance in an individual slot. You have to attack it methodically one at a time.

 

[Mungo Zen]

I recently replaced my V1 but about a week later started getting the same noise. I am sure the power tues, also recently replaced, are okay.

I put my old V1 12ax7 back in and same problem still.

I noticed that the fx loop volume and gain on all three channels affects how loud the noise is.

My questions are:

1 - you guys all talk about the tap test. Are you pulling the amp from the headshell before doing this? How are you getting to the tubes? Keep in mind I have a head not a combo.

2 - although I am confident the power tubes are okay, other than tapping them, checking for scorching etc, is there another test?

3 - if I do take the amp from my headshell, can I run it, assuming I don't stick my hand into the tray with all the capacitors etc, or are there any precautions that can be recommended?

Thanks!

 

[Talus]

So an update:

Well I failed to spot it before but one of the powertubes was arcing so I replaced that.

So, random crackling is gone, but there is a crackling noise that happens when playing the amp... This disappears after about 5-10 minutes however I'm also getting volume fluctuations that doesn't go away.

Time to start testing the preamp tubes I guess? Is there a likely suspect? Is there any easy way of getting at them? They seem pretty damned hard to access.

 

[flyfisherx]

I called Mesa customer service. Since I just bought the amp brand spanking new, they are sending me out a pre amp and a pair of power tubes to troubleshoot with. If you are still under warranty, call Mesa and they will take care of you. They have very good customer service.

 

[flyfisherx]

I replaced the V1 Pre-amp tube. Same issue. I then decided to replace the inner match pair of power tubes. Bingo! problem solved. BTW one of those tubes (original) did not fully seat in the socket. The new ones do. Maybe that was an issue??

 

[guitarp77]

Great to know you could solve it!

Always cool to read about how to fix the issues!

 

[fr0sty]

I get problems like this with my V from time to time. I normally replace all the power tubes and that clears it up. It started up again recently. I noticed it only happened on 45 watt mode (any channel). Rather than replacing all the power tubs (spendy) I look in the manual and found which power tube is only active in 45 watt mode. I had some known good mesa 6l6s laying around. Replaced that one and the noise is gone.

I believe the problem happens when I don't let the tubes warm up enough before turning the amp on. It doesn't happen every time I do that, but once in a while it triggers the spitting and hissing noise.

May be something I read about called cathode stripping.

 

[mesa metal]

i been getting this lately also...mostly a hissing noise when i turn the volume down on the guitar
i notice the noise in tweed mode and channel 3..

 

[ricorocks]

Had the same problem even worse, i was worried as hell man on a new "V". turned out to be a bad pre 12AX7 in V1 pos. Knock on wood... :wink: Good luck man and Rock on