Mark V 90 Question

The Boogie Board

Help Support The Boogie Board:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

richprice79

Well-known member
Joined
Apr 17, 2017
Messages
51
Reaction score
6
Good afternoon gentleman.

I have a Mark V I purchased online that arrived with 4 "groove tubes" power tubes. The amp is a 2014 model with what I assume are all of the original Mesa pre amp tubes. I like the amp so far and have found that Mark 1 is my favorite channel with the treble and presence dimed and the bass all the way off with no eq. This is one dark channel but setup this way is crushing when turned up a bit. Channel 3 sounds a bit thin for my taste by comparison but I can still find some sounds I like though not nearly as pleasing as my Mark V 25. This thing can really move some air! I have a few questions for the experts.

Are Groove tubes generally considered acceptable power tubes for the Mark amps?

Could they be the culprit of channel 3 not having very much grunt? (though still sounds good to be honest just not as good as channel 2)

The preamp tubes are at best 3 years old and there is no hum or micro-phonics to speak of (dead quite) so I don't think these would be an issue.
 
Hi, I have a Mark V and Mark V 25. Both sound very good. But the mark v 90w Sounds better on any channel than the mark v 25.
If you have the valves since 2014, you don't know the use they had. I think that the valves are not very good if you say Ch 3 does not hear well . Also the valves should have the bias recommended by Mesa. You can have grooves, but they are prepared for MESA bias.
if you have a MK25, you could change the preamp tubes to de Mark V (or only the CH3 preamp tubes V1, V4, V5, v6 and V7). if the problem continues, then the problem are the power tubes.
 
Groove Tubes are just tested and re-labelled versions of other tubes, like Mesa tubes and Ruby tubes. Their ratings between 4-6 fall within the Mesa acceptable ranges. Depending which groove tube model it is, it may in fact be the same brand as Mesa is currently using. They should be acceptable to use. Though Mesa does prefer you use their tubes during the 5 year Warranty period.

Also, you assume the preamp tubes are stock but since some tubes have been changed you really can't know unless you look. Tubes can affect the tone and feel of an amp even when they're good. And they can wear out and sound worse without reaching the obviously bad microphonic stage.

A number of guys have been having good luck using a JAN/Phillips or other 12AT7 in V4 or V7 on the Mark V 90w to take the high end a bit and make CH3 sound beefier. You can read about it here, and might have some luck trying that: http://forum.grailtone.com/viewtopic.php?f=33&t=73352
 
I think it's mostly a learning curve, I have channel 3 dialed in pretty solid now.
 
It is all about taste and what you like. A 12AT7 in V4 alone takes care of the thin tone as it reveals some of the mids, tightens up the bottom and shears off the high order harmonics that strips the drive characteristics of the iconic Mesa tone. I had gotten used to the CH3 characteristic but it also bothered me at the same time. Mine is a 2012. The JAN/Phillips 12AT7 NOS tube does the job quite well in V4, it may have a lower voltage gain than a 12AX7 but a lower gain in the V4 position wakes up the amp. (this has no effect on CH1 or CH2 except for a mild change to the reverb drive signal but I personally have not noticed anything dramatic).

Note that the Mark V is one amp that responds quite well to preamp tube changes such that characteristics can be tuned with different preamp tubes.

+1 on the GT. Those should be okay.
 
Back
Top