Mark V:25 Microphonic noise - HELP!

[VoronArgentum]

Just got my MarkV:25, and have two questions:

1. I got a very loud microphonic noise when I turn gaine and treble at 2:30 - 3 o'clock and the volume at noon. Does your MarkV:25 got the same problem or I've a bad luck?
Yes I read in the manual that Mesa advise do not use extreme settings with loud volume. but it's not so extreme. I mean it's not all the way up! Really confused about it

2. Is your fans loud as hell or I've got a broken one? I remember that it was able to turn it off in MarkV but here it is all time on and quite loud. Very loud!

Any help is really appreciated!

 

[jmontgomery]

It's probably a microphonic tube.
My fan is not loud. I don't even notice it.

 

[VoronArgentum]

Ok. It mean bad luck twice :mrgreen:

 

[Monstercastle]

My fan is pretty quiet as well. See if it spins by hand freely, without any noise or resistance. Possible it's a bad fan, but will is under warranty. Probably swap-able by you with basic tools if Mesa will ship you a new fan.

As for the microphonics, it's either a tube or you need to dial back the treble a bit. I wasn't having issues with mine, but I have since replaced the factory pre's with the SPAX7s because I wanted to put them in all slots. I also don't need the treble above noon to get what I need. Try dialing back the treble on the knob, but add back what you need on the GEQ or presence knob.

 

[VoronArgentum]

I will change this head tuesday in local store, already talk to my friend (because it's his store :lol: )
So we will look at this and compare with another head tuesday.

 

[pvdmac]

Can you guys tell me/point me in the right direction of how I would go to change preamp tubes...where would be the best place to start with taking per-installed tubes out for replacement. I have a Mk5-25 and am thinking of replacing tubes. It's pretty cramped in back of Mk5-25 for my hands...what do I start to take out first.
Cheers.

 

[VoronArgentum]

Tried 3 different Mark V:25 and they are all squeals at some point. So I choose one that is more stable and have quite fan

Demo arrive soon!!!

 

[VoronArgentum]

Can you guys tell me/point me in the right direction of how I would go to change preamp tubes...where would be the best place to start with taking per-installed tubes out for replacement. I have a Mk5-25 and am thinking of replacing tubes. It's pretty cramped in back of Mk5-25 for my hands...what do I start to take out first.
Cheers.

I think you need to take out chassis by removing 4 top screws or maybe removing the front panel. I don't open mine for the moment

 

[VoronArgentum]

So here is small demo with my Mark V:25

http://youtu.be/2UMvbPaQGpQ