Non-Tube-Related Noise From Mark IV?

[Inspired]

My Mark IV combo continues to have a noise in the background that is similar to what tubes do when they go bad. You know, that crackling/breaking-up noise. However, I've gone through every tube, replacing one at a time, both preamp and power tubes, but the noise continued after every possible swap. I unplugged the fan...the noise continues. (Insert blonde joke here.) I turned the reverb all the way down...the noise continues. It's not extremely loud, but it's always there. I really don't think it's tube-related since I went through the whole progression, and even had all new Electro-Harmonix 12AX7s in it at one point. (Note: I did return all the Mesa 12AX7s back to their original position once I realized they weren't the problem.)

Could it be a capacitor or some other electrical part going out inside? Or is this a normal sound for Mark IVs? I know they're loud amps by nature, but this sound seems out of the ordinary...

 

[nocluejimbo]

Try switching what outlet you are using, running it through a power conditioner, and/or moving it to try and eliminate noise.

That seems to work for most people with that problem.

 

[RussB]

bad push/pull pot?

something NOT in the amp making noise? does it make the noise when the amp is moved to another room/house?

 

[corm0001]

My Mark IV combo continues to have a noise in the background that is similar to what tubes do when they go bad. You know, that crackling/breaking-up noise. However, I've gone through every tube, replacing one at a time, both preamp and power tubes, but the noise continued after every possible swap. I unplugged the fan...the noise continues. (Insert blonde joke here.) I turned the reverb all the way down...the noise continues. It's not extremely loud, but it's always there. I really don't think it's tube-related since I went through the whole progression, and even had all new Electro-Harmonix 12AX7s in it at one point. (Note: I did return all the Mesa 12AX7s back to their original position once I realized they weren't the problem.)

Could it be a capacitor or some other electrical part going out inside? Or is this a normal sound for Mark IVs? I know they're loud amps by nature, but this sound seems out of the ordinary...

I had the same thign happen with Mark IV. I sent it in to be repaired, when the tech received it he opened it up(NOT AN EASY TASK) and found that the previous owner had spilt some liquid into the amp, and since it is so compacted with compnenets, it had no way to drain, and seem to have blown some capacitors and resitors. After $5 in parts and a professional cleaning, the amp works extremely well, with little to no noise now.

-So go get it cleaned, get the resisitos and capasitors changed and you should be good to go.

Cheers
SHawn C

 

[Inspired]

I had the same thign happen with Mark IV. I sent it in to be repaired, when the tech received it he opened it up(NOT AN EASY TASK) and found that the previous owner had spilt some liquid into the amp, and since it is so compacted with compnenets, it had no way to drain, and seem to have blown some capacitors and resitors. After $5 in parts and a professional cleaning, the amp works extremely well, with little to no noise now.

-So go get it cleaned, get the resisitos and capasitors changed and you should be good to go.

Cheers
SHawn C

That's kind of what I was afraid it might be. One thing I recently discovered is that the noise is real responsive to the 5-band EQ when you move the sliders, and that's whether you have the EQ on or not. For instance, on Channel 1 with the EQ off you can play with the EQ sliders and it affects the noise.

The amp wasn't totally brand new when I bought it. It was a floor amp that I know had been at the store for awhile, so no telling what all it's been through.

I'll take it to my local tech soon and I'm sure he'll hook me up.

 

[Reeko]

I had the same thign happen with Mark IV. I sent it in to be repaired, when the tech received it he opened it up(NOT AN EASY TASK) and found that the previous owner had spilt some liquid into the amp, and since it is so compacted with compnenets, it had no way to drain, and seem to have blown some capacitors and resitors. After $5 in parts and a professional cleaning, the amp works extremely well, with little to no noise now.

-So go get it cleaned, get the resisitos and capasitors changed and you should be good to go.

Cheers
SHawn C

That's kind of what I was afraid it might be. One thing I recently discovered is that the noise is real responsive to the 5-band EQ when you move the sliders, and that's whether you have the EQ on or not. For instance, on Channel 1 with the EQ off you can play with the EQ sliders and it affects the noise.

The amp wasn't totally brand new when I bought it. It was a floor amp that I know had been at the store for awhile, so no telling what all it's been through.

I'll take it to my local tech soon and I'm sure he'll hook me up.

Hey,
I have the EXACT same problem with my brand new MKIV. Sounds like crakling in the backround. Not really effected by volumes/gain/channel, but it does seem to get worse with changes to the EQ. I tried tube swaps etc.

Have you figured out the issue? I took mine in and the tech has not yet figured it out.

Also, have you noticed if your amp pops when you enable the EQ? Mine does (I am told it should be silent), I was hoping it might be related, bad cap perhaps?

 

[Inspired]

Strange. No, I haven't figured out the issue. I e-mailed my tech and he just said to bring it in and he'll fix it up. I just haven't gotten around to it yet.

Yes, I have the POPS! when I switch channels, too. Mine pops going into the Lead Channel and the Lead+EQ Channel.

I've had so many problems with Boogies, that it's amazing I still use them. They're very inconsistent, too. For instance, I've had two Nomad 55 1x12 combos. The first one was the best sounding amp I've ever had, until it went to hell and nobody could figure out what was wrong with it. So they sent me a new replacement, and it totally sucked. Never could get a good tone out of it.

 

[Reeko]

Interesting, as I have the same problem.
I called Mesa, and they say it should not pop when engaging the EQ.
(It even pops if I engage the EQ with my master volume on 0, so it is not being caused by the EQ's audio path, but I believe the noise is coupling in somewhere else.)

Mine also pops loudly if I switch Class A/simul or Triode/Pent , but I don't know if that is normal.

I am going to let my local authorized tech look at it (since it is there for the second time allready) , but Mesa was very opologetic and say to send it to them for a complete lookthrough if he doesn't get it fixed.

 

[Ed Pitman]

Hi All - know that this is an old thread but it caught my eye.

I once owned one of the first MKV's in the UK and I had a "popping" issue when changing channels. The problem was found by the then UK tech, a guy if I remember called Jim Kelly - basically he solder new LDR's on top of those there already. The problem was dramatically reduced....

Cheers

Ed

 

[Russ]

Something to consider too is the fact that tubes were never meant to be in the same enclosure as your speaker. Though the combo amp design is a popular one that still exists today, the tube manufacturers still do not manufacture their tubes to handle such abuse. The sound from your speaker may rattle the internals of your tubes and you may hear them as a note decays. In the case of a combo amp, it is just something that you have to live with. If you want to erradicate the problem try migrating into a head cabinet or a rackmount. Some have even reported that you can get the artifact type rattling from a head cabinet if you play loud. The SUS-4 mounts were supposed to help with the rattling and that is why Mesa started using the mounting system. It will not completely remove the rattling but it helps. If your tube internals are rattling then you will certainly hear them no matter what you do. New tubes may only reduce the rattling but it will return without a doubt. Best solution is to rackmount your amp chassis if possible to move it far from your speakers' vibration thus reducing the rattling of your tubes' internals.

Another source of rattling may be your speaker. If your voice coil goes bad it will make a rattling sound also. This is an easy fix by replacing your speaker.

If your amps circuit has been comprimised then it can rattle also even with having taken all precautions to stop the rattling. This can be fixed by either replacing the damaged components or repairing bad solder joints. If you cannot do this yourself you just take it to a tech and it can either be inexpensive or very expensive depending upon how long it takes them to find the problem and how much work your amp needs.

In any event, it would be a good idea to migrate your amp chassis out of the combo cabinet.

 

[Boogiebabies]

Hi All - know that this is an old thread but it caught my eye.

I once owned one of the first MKV's in the UK and I had a "popping" issue when changing channels. The problem was found by the then UK tech, a guy if I remember called Jim Kelly - basically he solder new LDR's on top of those there already. The problem was dramatically reduced....

Cheers

Ed

Good call Ed. LDR's like to pop. Some pop as new and some pop after decades.

If you know Jim Kelly, you are in good company. If you know the other Jim Kelly, then get some good football tickets.