Mesa Triple Crown TC-50 2nd & 3rd channels noisy

[maxem]

Had posted this on another page that had a discussion about this issue and thought I’ll check the Mesa forums while I wait for Mesa support to get back to me.

Channel's 2 & 3 on my TC50 are noisy (crackle & hiss)...channel 2 isn't too bad but there's a lot of crackle & hiss on channel 3.

I tried swapping out the V3 & V4 tubes that correspond to channels 2 & 3 as per the manual, with new tubes and it did not solve the problem. I also tried swapping the power tubes with new ones and that didn't help either. Also tried replacing the other 12AX7 tubes and the 12AT7 but had no luck.

The noise is there even though no guitar/cable is connected to the input!!

Is there something else I could try and/or am I missing something?

 

[jnoel64]

Did you try swapping out V1? That's the main input stage for all three channels, isn't it? I use the SPAX7 in V1 in my TC50. Mine is a very quiet amp, regardless of gain level or channel. Yours does not sound like a "normal" situation to me.
I've posted this before, but my 12AT7 had bent pins from the factory. Never noticed until I pulled it. I replaced it with a JAN-Phillips 12AT7 just to be safe. But that's just for the loop, isn't it?

 

[maxem]

Did you try swapping out V1? That's the main input stage for all three channels, isn't it? I use the SPAX7 in V1 in my TC50. Mine is a very quiet amp, regardless of gain level or channel. Yours does not sound like a "normal" situation to me.
I've posted this before, but my 12AT7 had bent pins from the factory. Never noticed until I pulled it. I replaced it with a JAN-Phillips 12AT7 just to be safe. But that's just for the loop, isn't it?

Believe V1 corresponds to channel 1 as per the manual. I did try swapping that and the other 12AX7's and 12AT7 but had no luck. No damage to pins or sockets from what i can see.

Temp fix i have is a noise gate in the effects loop but need to get this fixed. Have to send it in to get it looked at/serviced

 

[JPBoogie]

Hello Maxem, this will sound silly... just doing some elimination process here. Since you have tried with the tubes and nothing worked... Have you changed where you plug your amp recently? Have you changed anything in your house (i.e. modems, routers, lighting, etc)? I ask because I got an awful crackling noise once because my router was on the same circuit braker than my Boogie. Almost sounded like someone was making popcorn LOL. Anyway, hope this helps.
Oh, have you tried replacing your power tubes? Those channels are high gain so would amplify any noise on the line... would you get the same noises if you put a boost in front of Channel 1? Let us know what you found please and good luck fixing it, hopefully not an expensive solution.

 

[Eevil]

Had posted this on another page that had a discussion about this issue and thought I’ll check the Mesa forums while I wait for Mesa support to get back to me.

Channel's 2 & 3 on my TC50 are noisy (crackle & hiss)...channel 2 isn't too bad but there's a lot of crackle & hiss on channel 3.

I tried swapping out the V3 & V4 tubes that correspond to channels 2 & 3 as per the manual, with new tubes and it did not solve the problem. I also tried swapping the power tubes with new ones and that didn't help either. Also tried replacing the other 12AX7 tubes and the 12AT7 but had no luck.

The noise is there even though no guitar/cable is connected to the input!!

Is there something else I could try and/or am I missing something?

Have you tested plugging guitar straight to fx return? Does it crackle then? Just to check if the noise is coming from preamp or power amp..

 

[bandit2013]

Hello Maxem, this will sound silly... just doing some elimination process here. Since you have tried with the tubes and nothing worked... Have you changed where you plug your amp recently? Have you changed anything in your house (i.e. modems, routers, lighting, etc)? I ask because I got an awful crackling noise once because my router was on the same circuit braker than my Boogie. Almost sounded like someone was making popcorn LOL. Anyway, hope this helps.
Oh, have you tried replacing your power tubes? Those channels are high gain so would amplify any noise on the line... would you get the same noises if you put a boost in front of Channel 1? Let us know what you found please and good luck fixing it, hopefully not an expensive solution.

Yeah, this is good advice.

I have a BAD100W that gets a lot of use. I never hear any noises such as a bad preamp tube (typical popcorn noises) except when the guitarist comes over to jam, the amp sounds like it has bad preamp tubes and is going to die any time during our practice session.

Turns out he forgets to take out his cell phone out of his front pocket. He also tried placing it on top of the amp, that made the noise in the amp far worse. Cell phones will also make odd noises occur in the amp and when they are not present all is good. Effects that have batteries can do this too if the battery is low. Same with active pickups in a guitar if the battery is on the weak side.