Mark V, rediscovered why I like this amp.

[bandit2013]

I have had my Mark V (new) since November of 2012. What I had at my disposal was an OS Recto Slant cab. Early on I was impressed with this amp but as I experimented more and more with the Mark V I began having issues. I kept blowing one or both of the center tubes. After replacing them, it did not take long to get to red plate territory. It was a quick kill on tubes operating the variac power. WTF? In short, it seemed that the 45W mode was hard on the tubes. In retrospect, it may have been micro-fractures in the carbon composition screen resistor on one of the center tubes. After that eventually burned out and I replaced all of the screen resistors with more reliable components, things were better but still had issues with 45W mode causing red hot seams on the plates (only when playing). In 90W mode never had an issue with tubes red plating, but when in 45W mode, one or both of the center tubes always got the 6V6 glow on the plates. Since I have become used to using the amp in 90W mode, it does not appear to have the same appeal to me than it did operating in the 45W mode. Also after obtaining some other amps (RA100, Roadster), the Mark V is no longer at center stage and does not get used as much. Once in a while I will power it up and use it. I originally bought the Head but converted to combo for more versatility as the open back combo sounds much better with the clean channel than does the 412 cab. Just for kicks I decided to run the amp at 45W, and if it burns up a tube, that was okay too. I am just not really into the V anymore. Holy crap, where did that sound come from? I channeled the amp into the Recto cab and instantly fell in love with the amp again CH2 and CH3, all voicings were explored, even changed from pentode to triode, used the rectifier or diode on the other two channels. This amp will sound incredible though a V30 cab at the 45W power setting. I was amazed that I was able to play for 2 hours and no hint of red seams on the plates. Unfortunately, the clean channel suffered with the V30, did not sound good at all when compared to the EV I have in the combo. Just for kicks, I enabled the 90W setting on CH2 and CH3 while still plugged into the 412 and was not impressed (brittle is back). The Mark V sounds the best in 45W mode.

 

[Monstercastle]

What tubes were you using in the V that were red plating? Were they Mesa branded or other? Just bought the V head a couple months ago and love the tones in all settings. I have no intention of tube rolling in my Marks (either the V:25 or the big V), so that's why I'm questioning such short tube life and the brands you were using.

As an aside, I put my 412 Mesa with V30's in storage and am using the widebody 112 with the closed back C90. I really like that cab/speaker better than the V30's.

 

[bandit2013]

They were all Mesa tubes. (one reason why I began using alternate tubes). I suspect I had a component issue (and probably still do) as well as lost one screen resistor about a year after of ownership. Got it repaired and all is well. Still have not had much luck with the Mesa power tubes in the V. They either sound terrible or they start getting red slivers on the plates in short use (happens in 45W mode only). I have had great performance from two sets of =C= (no failures). I have also tried the Mesa tube again and have had better luck with out heating up the plates. Used them for a few months and put the =C= back in due to tonal preference.

The Roadster on the other hand, All Mesa tubes.

 

[Hollis]

I prefer my Electra Dyne on its 45 watt mode too(it's a Simul-class amp like the Mark V).

 

[bandit2013]

The V is an interesting amp, it responds quite well to preamp tube changes of other varieties as well as different power tubes. That being said it also has its drawbacks too, such as ice pick highs with moderate volume levels. The Mesa power tubes do have a warmer tone when compared to others but they seem to sound a bit thin in the V in comparison to others. One exception would go to the Ruby 6L6GCMSTR which is the same tube branded by Mesa (as I was told), nice bold lows, mids are pronounced well and the highs are not piercing. Most tubes from Russia will have that ice pick presence (manufactured by Reflektor, aka: new Sensor trade names Mullard, Tung Sol, Svetlana (not =c=) Sovtek just to name a few). I seem to favor the tubes with dual getters (=C=, TAD ) which are constructed similar to the old tubes of yesterday (SED or =C= can be quite brutal in the higher frequencies, but everything else abut the tube makes up for it). The dual getter does not mean it will sound good. However, my favorite power tube of all time other than the RCA's that came in my Mark III when I bought it would go to the Chinese coke bottle Mesa tubes which were originals in the Mark IVb (Unfortunately they suffered a quick death in the Mark V when I was having tube issues early on.) In a pale comparison, the Mark IVb responded quite well with the current Mesa 6L6GC tubes. Ran them for a month before selling the amp to fund my drum kit. I sort of miss it, but not as much as the Mark III.

I can respect that the Mark V is different than the Roadster and RA100. With the right speaker choice this amp can be a monster in the Metal arena driving the CH2 crunch in high gain setting. The Mark IV mode on CH3 seems to have a bit more compression than did the Mark IVb. I will have to double check my preamp tubes to see if I have current Mesa 12AX7's (JJ) or if the amp still has the vintage Mesa 12ax7 (Chinese with square getter, also the less prone to noise). I think one of the best features is the Class A 10W mode. Despite how often I play though the Mark V, it is a keeper. Getting used to the gain, tone and presence controls and learning how it reacts to shape your sound will take some time. Still it is much easier to dial in than its predecessors.

I am hoping I can use 45W mode more often with out issue. I actually love the character of the amp in the variac power and 45W mode but that is when I had tube issues and red plating. No more than 20 minutes of use, the plates will get red hot at the seams with a gradual dispersed red color spreading from the seams. If I see it and stop playing but not turn the amp off, the tubes will cool down quickly. Also only noticeable in the dark. Perhaps that is an effect of playing loud in the 45W mode (it will still happen in full power too but will take more time to occur). My last session using 45Wmode I noticed that the tubes did not overheat and that was a 2 hour jam (I could not stop playing :shock: ).

 

[Shai`tan]

Sounds like a Mrk V issue that Boogie really should be looking at.

 

[bandit2013]

I believe the issue I have experienced with the amp thus far is not a common issue with the majority of the builds. If there was a known issue, it would be an opportunity for Mesa to revise what is necessary, especially for a flagship product like the Mark V. I doubt that I would buy another Mark V, but overall it is a good amp regardless of the tube issue I am having. I have not given up on the amp and will eventually purchase a tube probe to get plate current and voltage measurements. Also since I rarely use the 45W mode due to the past experience with this amp, I am not totally bummed out about it. However, the 45W modes in all channels is were its at.

 

[Monstercastle]

I too doubt there is an issue here. While I'm new to having the Mark V head (couple months now, purchased brand new) I'm sure the amp meets Mesa's high standards for quality and support. If I didn't think that I would have bought a cheaper less capable amp.

That said, I will keep an eye on it and will see what happens with tube life. I have a spare set in stock, because well....it's a tube amp, and tubes are consumable items to tube amps. Much like filling the gas tank and getting oil changes in a car. People don't think twice when they fill the tank for $50, but complain when they have to drop $50 for a set (pair 6L6 mesa) of tubes that last months or more? I don't get it.

 

[YellowJacket]

It looks like your amp is still under warranty. Maybe you 'bandit2013' need to contact Mesa about this?

 

[bandit2013]

Perhaps I should.

 

[bandit2013]

This is becoming interesting. I have spent the past hour running the amp 45W on all channels, tube set for both CH1 and CH2. This time with the variac power. I could not even get a sliver or slight tint of red on the plates. That is great for now. I would not doubt considering the quality of tubes these days as not being up to par to how they were manufactured prior to changes starting in the early 80's. Also I realized why I love the RA100 so much, since I can get very close to that sound with the 45W power settings with the Mark V (yes, using the same cabinet I use with the RA100).

I think I need a V30 with a 100W rating so I can stuff it in the Mark V combo. I may consider opting for a Scumback BH75-LD with a 100W VC.

 

[bandit2013]

Had to go back and play some more. There is something about this amp that I must part with it. Sounds really good through the 412 cab with V30. I had pulled the smaller Egnator 412 cab out of the other bedroom (has different Celestion speakers and is 16 ohms) and plugged it in as a safe mismatch. There is a bit of a tone difference between the two cabs. That was really interesting. Decided to plug in the EVM12L in the combo in the 4 ohm jack (per the manual this is a safe mismatch, 8ohm speaker in 4 ohm jack with 16ohm speaker in 8 ohm jack). The sound gods have come back to life. After all that, I returned the Mark V to the two EV speakers (both plugged into the 4 ohm jacks) not bad, has some balls and finally just the combo speaker. My love/hate relationship is going in the wrong direction, but I hope it will lead me to the correct path. I am parting myself from EV completely or in partial. Just ordered a Jensen BlackBird 100W Speaker for the Combo. I did like the WGS BlackHawk but the Mark IV had its way and burned up the voice coil. I figured the Jensen BlackBird would have a better chance of survival. If it blows up, I have 5 EVM12L speakers to go back to. I may keep the other in the extension cab for a little longer.