Mark 3 help!

So I have had the head for almost a week now. I was playing the head through a recto cab at my house and it sounded AWESOME!

I was so excited to take it to practice last night and just crush my rhythm guitarists bugera. I hooked it up, let it warm up and turned it up. Well my luck it souneded like ***! . It lost ALL the lowend, the highs were very brittle and the mids were really mushy. Nothing like it sounded at home.

I dont understand what happned between being at my house and moving it to the practice space. I did notice that when I turned it on only one tube was glowing blue but the others weren't. I know is normal for a tube to glow blue but only one of them?

I was so disappointed , Do you guys have any Ideas as what may have happened?

Were you running the same volume settings, guitar and cabinet?

Perhaps something got jostled loose during transit, did you check all the tube connections?

same speaker cab?
same speaker cable?

how is it sounding today?

this happened to me a couple of times ... you have a loose power tube i bet. reseat all tubes.

I was running the same settings but i was tweaking them for a while until i gave up.

It was the same speaker cabinet and speaker cable.

I havent had a chance to play it today.

rvschulz said:

this happened to me a couple of times ... you have a loose power tube i bet. reseat all tubes.

Click to expand...

Wow, could it be that simple?

Boogiemark3 said:

I was running the same settings but i was tweaking them for a while until i gave up.

It was the same speaker cabinet and speaker cable.

I havent had a chance to play it today.

rvschulz said:

this happened to me a couple of times ... you have a loose power tube i bet. reseat all tubes.

Click to expand...

Wow, could it be that simple?

Click to expand...

Yep.. thats why I recommended you check your tube connections

Sometimes you just need to turn it completely off and then back on.

Hey guys thanks alot! I really appreciate everybodys help. I am hoping that it is just a simple solution like a bad tube connection.

I will check on it tonight and see if that is the problem. This is my first mesa amp so I don't know to much about them execpt that I really love the tone I was getting from it at home.

Okay, I went over all the tubes and tube sockets. Did a deep cleaning and reseated all the tubes. I cleaned all the input jacks, and the reverb tank connections.

I am still getting that flubby, harsh distortion. The lead channel is very weak sounding. almost like it has very little gain.

The clean is nice but the crunch and lead channels seem very week. Also once in a while there will be a surge in volume and the amp will start to sound more full but then it just goes away.

I had been doing some reaserch and someone suggested changing the LDR's and the caps. Would doing this fix the problem?

Boogiemark3 said:

Okay, I went over all the tubes and tube sockets. Did a deep cleaning and reseated all the tubes. I cleaned all the input jacks, and the reverb tank connections.

I am still getting that flubby, harsh distortion. The lead channel is very weak sounding. almost like it has very little gain.

The clean is nice but the crunch and lead channels seem very week. Also once in a while there will be a surge in volume and the amp will start to sound more full but then it just goes away.

I had been doing some reaserch and someone suggested changing the LDR's and the caps. Would doing this fix the problem?

Click to expand...

You could have a bunk preamp tube.. I'd start checking those out. Especially if you're getting random surges in volume.

Had the same problem. I retubed the whole preamp and it went away completely. Try that out.