How to remove chassis on Mark V

[ACShreds]

So I'm trying to swap preamp tubes on my mark V but i can't seem to get the chassis out of the headshell. I unscrewed the top four screws but I'm not sure exactly how to get it to slide out. Anyone got any vids or pic that'll help explain what to do haha. I took off the faceplate but of course there's a piece of wood behind it that doesn't remove to get to the preamplifier tubes.

 

[DEWD]

Above the transformer there is a bolt with a plate on the end of it. You have to unscrew that to get it out of the chasis.

 

[steve_k]

You don't have to remove the chassis to change preamp tubes....but, you do have to plan the order you put them back in. Tight squeeze, but can be done.

Steve

 

[lolzgreg]

It's a real fucking pain to get out. The chassis is likely stuck on the front panel. Turn the amp upside down, unscrew the front panel, and pull it off. The amp needs to be upside down to remove the pressure. You also HAVE to take the front panel off because you will likely damage the piping.

Also, only try to take off the wheat grill of the front panel; do not try to remove the wood behind it, because it's screwed and glued.

Good luck.

 

[miguelr]

It was a PITA but I managed to swap all preamp tubes without moving the chassis. But believe me I tried removing the chassis and failed haha.

 

[ACShreds]

Above the transformer there is a bolt with a plate on the end of it. You have to unscrew that to get it out of the chasis.

If you have the amp right side up, and are looking at the back of it. Is it the screw that has a nut and it connected to the headshell and what i assume in the transformer? Because thats like the only thing left that can possibly be holding the chassis in place. If i pushed on the part where in the input jack is it'll start to slide out of the back but the right side wont move.

 

[Big Rich]

i do it without taking the chasis out .... you do need to obviously take out the power tubes, but im gigantic and my hands are massive and i manage to get it to fit in the tight spot which is the v1 position

 

[DEWD]

Yep thats the only thing holding it in besides the four screws on top. You have to use a wrench or pliers to hold it down by that circle plate and another wrench to turn the nut. It is a PITA compared to most amps but after you do it once, its easy. Like the other dude said, be careful of the piping on the front when you slide it back in. It tends to get in the way.

 

[steve_k]

Yep thats the only thing holding it in besides the four screws on top. You have to use a wrench or pliers to hold it down by that circle plate and another wrench to turn the nut. It is a PITA compared to most amps but after you do it once, its easy. Like the other dude said, be careful of the piping on the front when you slide it back in. It tends to get in the way.

A big tip for Mesa Mark owners....if you do pull the chassis the first time, use the opportunity to make it so you don't have to pull it a second time. Remove the grill, take a drill and a keyhole saw and cut out a 3x4 slot in the front to give you access to V1-V4. Reinstall grill. Thank me later.......

Steve

 

[ACShreds]

Yep thats the only thing holding it in besides the four screws on top. You have to use a wrench or pliers to hold it down by that circle plate and another wrench to turn the nut. It is a PITA compared to most amps but after you do it once, its easy. Like the other dude said, be careful of the piping on the front when you slide it back in. It tends to get in the way.

Ok just so im 100% sure about what to do so i dont break anything. I hold the nut at the bottom of the screw with a wrench and then uncscrew the screw at the top where its connected to the transformer and the whole thing will unscrew down out of the transformer? Sorry if im a broken record but i just want make sure i have the exact instructions before i go and break the amp apart or something haha.

 

[tfridgen]

Yep thats the only thing holding it in besides the four screws on top. You have to use a wrench or pliers to hold it down by that circle plate and another wrench to turn the nut. It is a PITA compared to most amps but after you do it once, its easy. Like the other dude said, be careful of the piping on the front when you slide it back in. It tends to get in the way.

Ok just so im 100% sure about what to do so i dont break anything. I hold the nut at the bottom of the screw with a wrench and then uncscrew the screw at the top where its connected to the transformer and the whole thing will unscrew down out of the transformer? Sorry if im a broken record but i just want make sure i have the exact instructions before i go and break the amp apart or something haha.

So... I guess you do need to instructions to know how to rock
Just joking, I really have nothing of value to add. Good luck!

 

[ACShreds]

Yep thats the only thing holding it in besides the four screws on top. You have to use a wrench or pliers to hold it down by that circle plate and another wrench to turn the nut. It is a PITA compared to most amps but after you do it once, its easy. Like the other dude said, be careful of the piping on the front when you slide it back in. It tends to get in the way.

Ok just so im 100% sure about what to do so i dont break anything. I hold the nut at the bottom of the screw with a wrench and then uncscrew the screw at the top where its connected to the transformer and the whole thing will unscrew down out of the transformer? Sorry if im a broken record but i just want make sure i have the exact instructions before i go and break the amp apart or something haha.

So... I guess you do need to instructions to know how to rock
Just joking, I really have nothing of value to add. Good luck!

haha when it comes to rocking out im a natural, but doing tech work on amps is a whole other story.