Needin help with my Mark IV.

[Sickindian]

Hi

First of all want to say hello to all of You and hope that i'll get help from people that have more experience with tube amps than me.

Ok. I've recently bought Mark IV A version with the 2X12 Black Shadow Mesa cab but the sound isnt as i thought and heard on clips.
I use John Petrucci 2006 signature model with an "old" pick up but it sounds weak and it's not that crunchy and punchy as on clips.
I bought it from a woman(musician) and my thoughts are that there might be a right time to replace the tubes but i would like to know which ones should i pick, so i will have this kind of crunchy, articulate, sterile sound?

Many Thanks
Adrian

ps. i can post pics if you need and btw should the tubes be lightning bright or kinda candle light?

 

[silentrage]

I'm no expert but I'd like to chime in anyway.
Sounds like you might be getting corrosion in your FX loop, my last amp had a drastic drop in volume for no reason. I read some posts that said using a contact cleaner on the FX loop jacks and sticking a lead in and out of it a few times can remove some rust and give you a better signal, and that worked out for me.
So I would suggest you try that first before replacing tubes.

 

[MusicManJP6]

A retube is always a good idea on an amp with unknown tubes in it. Keep the old tubes for spares. I bet it will sound just fine after a retube. If not then you may have to take it to a tech.

 

[Sickindian]

Ive got two siemens tubes on both sides and two original mesa boogie in the middle so im not sure if that can be a non matching tubes issue and im not pretty sure about this corrosion as i dont have any signal drops its just the fact its not that vicious/crunchy attack sounding as i heard like on youtube.Maybe the A version is an issue?

I think ive got 2 spare tubes but which ones should i replace 4 on the front or 2 on the back?(ive got the small ones)
Because ive read somewhere that ones are responsible for preamp and others for power amp is that true?

 

[MrMarkIII]

Do you have the manual? If not, search for it on this site and read it. (The manual on the Mesa site is for the "B" model.)
If your knowledge of tubes consists of "big" ones and "small" ones, you need the manual. It's got lots of sample settings and info on how to change tubes, etc. Good luck and hope this helps.

 

[MrMarkIII]

Do you have the manual? If not, search for it on this site and read it. (The manual on the Mesa site is for the "B" model.)
If your knowledge of tubes consists of "big" ones and "small" ones, you need the manual. It's got lots of sample settings and info on how to change tubes, etc. Good luck and hope this helps.

 

[Sickindian]

Do you have the manual? If not, search for it on this site and read it. (The manual on the Mesa site is for the "B" model.)
If your knowledge of tubes consists of "big" ones and "small" ones, you need the manual. It's got lots of sample settings and info on how to change tubes, etc. Good luck and hope this helps.

I actually do!An old original one but i never had time to have a look at it . My knowledge is biger than that "big, small" tubes but its hard to see in chasis which one is 12ax7 and one on the front but anyways i gotta get into manual.

Cheers