Mark IV doesn't quite sound right...

[ryan1234]

I recently purchased a used mark iv on ebay. Even though I had never played one before, I had played a mark v at gc and I loved it. Since I didn't have the money for a v I went for a used iv. But I digress... I got this amp and something doesn't seem quite right. First off I'm getting a lot of buzzing. But more importantly, the distortion sounds more like fuzz and overall the tone is kind of harsh. Also I can't play on the clean channel without getting some breakup. I replaced all four power tubes and it didn't fix the problem. I know it's a complicated amp and I have spent a lot of time messing with the settings but to no avail. It's like it's operating at 60% of where it should be tone wise. Definitely no where near the mark v I played previously. I'm not bashing the mark iv, I've listened to some sound clips online and I'm fairly certain something isn't right with mine.

I want to take it to a shop but I would feel very foolish telling them I was there because "my amp doesn't sound good". I'm not sure I trust this guy to be completely fair in an evaluation of my amp (even if there is nothing wrong with it) if I'm going in with a problem like that. So, do you guys have any ideas?

Any help will be much appreciated.

 

[Rob Lockwood]

The clean channel on the Mark iv should give a very clean sound with no break-up unless the gain is set really high - usually above 8 depending on your pickups output. If you cant adjust the gain/clean channel master to get a good strong clean sound then something is wrong. The fuzzy distortion could be a subjective thing but the clean problem and the buzzing is a definite fault that a shop should recognise.

It could be a preamp tube problem especially if you dont know when they were last changed. You could buy one tube or get a known good one and swap each one in turn to see if there is any effect, or if the amps history is unknown it may be better to replace all 5 then you are starting from a known point. As there is a problem in the clean channel V1 and V2 or the phase inverter V5 would be the most likely to be causing the problem.

One check you could do is to plug your guitar into the effects return socket. You should get a very clean sound although quite low volume. If you still have buzzing and distortion then the problem is in the V5 phase inverter tube or the power amp side.

 

[topcat0399]

I recently purchased a used mark iv on ebay. Even though I had never played one before, I had played a mark v at gc and I loved it. Since I didn't have the money for a v I went for a used iv. But I digress... I got this amp and something doesn't seem quite right. First off I'm getting a lot of buzzing. But more importantly, the distortion sounds more like fuzz and overall the tone is kind of harsh. Also I can't play on the clean channel without getting some breakup. I replaced all four power tubes and it didn't fix the problem. I know it's a complicated amp and I have spent a lot of time messing with the settings but to no avail. It's like it's operating at 60% of where it should be tone wise. Definitely no where near the mark v I played previously. I'm not bashing the mark iv, I've listened to some sound clips online and I'm fairly certain something isn't right with mine.

I want to take it to a shop but I would feel very foolish telling them I was there because "my amp doesn't sound good". I'm not sure I trust this guy to be completely fair in an evaluation of my amp (even if there is nothing wrong with it) if I'm going in with a problem like that. So, do you guys have any ideas?

Any help will be much appreciated.

I'm not so sure you should ever buy an amp or amp type you've never played. A Mark V is not a Mark IV.
Some people never get used to a Mark IV - its not for everyone.

You have to spend alot of time with a Mark IV at first - I HATED mine for the first year: Now I wouldn't live without it.
In fact I have to live without it for now because its at Mesa for overhaul and I have to use my sub-par Fender Twin (my FORMER go to...). The entire band misses my Mark IV.

Now that you have it:

Play with it alot. Try all different settings, Don't be afraid to move the tubes around to see if there's improvement.
This forum is FULL of sample settings and experience - read read read.

A Mark IV just played in a room by itself can sound harsh. But that "harshness" in a band setting shines. It sits perfectly in a live mix. If its overly harsh then your settings are probably too extreme. Read up. If you want something that just sounds good in the room then get yourself a fancy digital sound processor. In my experience - something that sounds warm and fuzzy and happy in a room is lost and weak in a live mix. A Mark IV is an IN YOUR FACE amp. It doesn't forgive anything. Its made me a much much better player.

Make sure the BUZZ is not electrical power related. My MkIV is dead quiet. If you think the buzz is distortion related - set your channel gains lower and your outputs higher.

Good luck and welcome to the Maaahhhhkkk side skywalker.

 

[dodger916]

Do you know the age of the amp? Serial number would help; your settings too (all switches and knobs).