A Lemon?

After trolling through the AT7 Saturation Mod thread for months, I was finally able to buy a 2009 Mark V. The previous owner told me that he still had the original tubes in the amp. I honestly kind of doubt that judging from the wear on the tube sockets. He also told me there was a JFET replaced on the reverb circuit and I have the Mesa invoice for the repair.

Right from the start, I found Ch 3 to not have much drive. I dimed the gain on MKIIC+ mode, and, honestly, my Electra Dyne had much more gain in comparison. The lo gain mode of the Dyne dimed had more gain and saturation. MK IV mode was a little better, but not by much. With the original tubes, Extreme mode was very harsh. I blamed the 2009 tubes and replaced every tube in the amp, including the rectifier. I spent several hours going through the amp, trying different settings, guitars, cables, speakers, etc, and still the gain just isn't at the level I know it can be from all the demos I have watched. All these tests were done in full power, 90 watt mode, with and without the GEQ and it's variations.

Ch 1 also didn't seem as rich as I have heard online. I know videos are never the same as in person, but I had higher expectations and also found Clean and Fat modes to feel like they were on the edge of break up with the gain at noon. With no prior Mark experience, I don't know if that is expected, but I would tend to doubt it.

Ch 2 was kind of lifeless. It didn't matter if I used my EVM, V30, C90, or any of the WGS variants I have. The WGS 2x12 with an ET90 and Reaper HP had the most sparkle, but no matter what I used, it just wasn't all that thrilling.

Very disappointed now, and I don't feel like I can't sell it in its current state with a clean conscience. I will probably have to bite the bullet and send it back to Petaluma. So much for a great bargain! Any other suggestions are welcome. It's pretty easy to be blinded by disappointment.

I had to have the same reverb repair on mine, somewhat common on early models. Find another Mark V and compare it . There must be a used or new one around were you live?

Not much around me aside from Guitar Center. They have a Nomad 45, but nothing else. There is supposed to be an authorized repair center here, though. But after reading customer comments, I question if I will ever get my amp back, let alone fixed.

i always boost ch 2 & 3 with a custom ts808. i find it kinda dull without. also, unless your playing bedroom levels it's more about tight than gain. i just went for a new tone, a cross between overkill and pantera on iv mode, 750 all the way down, 6600 and 80 almost all the way up, and crank it, and it sounds mean and tight. channel 1 i have the gain at 10 o clock and the master at 2:30 on 45 watt tube, and crank it also for tight and sweet .

Tightness, I can completely agree with. My TC-50 can be much more boomy without it's mode switched to tight. I considered adding by BB to the mix, but honestly believed I shouldn't have to.

You don't. Something is wrong. Maybe just tubes, but this thing has plenty of gain in all three modes of C3. Try tubes first, turn your loop on and off and see if that changes anything. Flip the power modes... just see if any of those things make a difference. If not, I wouldn't even consider taking it to a repair shop until after a complete retube. People don't normally lie about how old the tubes are, usually it's the opposite.

Tubes were my original concern. But there literally was no difference between the original and new tubes. I did quickly flip through the power modes (and there were obvious differences in output volume), but did not try disabling the loop. That will be up next. Thank you!

Dreamtheaterrules said:

You don't. Something is wrong. Maybe just tubes, but this thing has plenty of gain in all three modes of C3. Try tubes first, turn your loop on and off and see if that changes anything. Flip the power modes... just see if any of those things make a difference. If not, I wouldn't even consider taking it to a repair shop until after a complete retube. People don't normally lie about how old the tubes are, usually it's the opposite.

Click to expand...

I wasn't talking about boosting to add gain. I along with most people boost their 5150's and there is tons of gain. But yes, there should be plenty of gain on tap.

All my tests were with the loop set in footswitch assign (and footswitch was not plugged in) but I did NOT have it set to hard bypass mode. Once I get through this next nightmare gig, I will have to give it another round of tests.

What are you running for settings?

The Treble control on CH3 also adds gain, and usually will be set above 2:00, and bass lower to reduce flub.

If it's a 2009 one it might be the original circuit released which has a little bit higher gain but was a touch harsher. Mesa made a revision around 2010 to reduce the gain and some of the high end on Ch3. But that sounds like you aren't getting as much as you expected.

Also, consider using the Graphic EQ in more of the V scooped shape? The Channel normally is so mid focused and tight that you don't realize how much gain is there until you bring out more of the high and low end.

Otherwise, getting a tech to look at it might be the way.

I have used many of the settings I have seen here, especially Apeman's for his Saturation Mod. That was my entire motivation for getting a V in the first place. I have used the GEQ in just about every possible configuration, scooping, using the preset at various levels, etc. In Apeman's first post on the saturation mod, he shared a link to his settings, which I copied verbatim. I have also tweaked the treble, bass, and mids, high, low, and almost everything in between. I spent an entire evening tweaking the amp just about every way I could, and only Extreme mode really had any guts - but was not too pleasing to hear. In the process, I tried not only the original tubes (which I was told were stock), and new tubes. The best thing that came out of the whole process was just how good EHX 6CA7s sounded in the V. But, I also used some TAD 6L6STRs, and some new Mesa EL34s. I also had 2 different matched pairs of new Mesa 6L6s. I tried all brand new JJ's in the preamp, switching them around way before I thought about adding the JAN-Phillips AT7. From all the sound clips I've heard all over the interweb, I simply did not have the same amount of gain. Speakers used were an EVM 12L, WGS Reaper HP, WGS ET90 (and those 2 WGS paired together), and a V30. When my Celestion Redback arrived, I gave it a shot, too. I changed cables, guitars, everything I could think of. My last experiment is to hard bypass the loop. Just haven't had enough time to sit down with it again. The chassis has 8-26-2009 written on it, so, yeah, I assume it was one of the first generation.

Apeman is using a Mahogany body guitar, so that might make a difference even if you are using the same settings. Like Apeman, I have the 12AT7 at V6 and settings are quite similar, except presence is at 1 0' Clock.

Regardless, it does sound like your Mark V might have something lacking with all the permutations and combinations you have tried. Would it be too much for you to ship it to Mesa for a diagnosis ? I am sure they can find out if there is an issue.

From what I've seen on Mesa's site, it will cost me about $200 plus shipping to send it to Petaluma. There is supposed to be a certified Mesa tech not too far from where I live, but his FaceBook comments scare the crap out of me. Things like "Bring back the equipment you stole..." and "I never got my gear back...." Different users a couple years apart. Don't think I'll be trusting them, lol!

My LP is mahogany - just don't play it too much since it has P90s in it. Most of the other guitars I have sport pretty hot pickups - all passive.

I am thinking I will have to bite the bullet and send it to Mesa.

You have a problem somewhere in the amp. If fresh preamps tubes do not cure the issue there may be something else at play. Confirm that the reverb tank is connected properly (white wire towards the rear of the chassis, dark gray/black towards the front. If the reverb tank is reversed the amp will not work very well if the reverb circuit is active. Note if you are not using the footswitch connected, the Reverb is active by default.

All three channels (CH1 in tweed) have enough drive to sound a tree shredder. If it is weak or low in signal chances are a bad tube may be in the signal chain or there is something on the circuit board around the tube sockets causing a fault. Compressed air usually will help displace any debris.

My concern considering the age of the amp, are there any mods done to the amp? Just a thought only... If you open it up, take several pictures of the PCB's inside and perhaps someone else with the same model year may be able to identify if there are any visual differences. I found a poorly installed mod in a Stiletto Deuce that way and removed it, sounded better without the extra parts installed.

The tubes I purchased to re-tube the amp were not Mesa tubes aside from the rectifier tube. But, all my preamp tubes were JJs, and I told TubeDepot what amp they were going in. So, I just ordered a full compliment of Mesa tubes. That probably won't make any difference, but before I send it back to Petaluma, I want to be sure I have all new Mesa tubes in the amp. I mentioned before that it had the reverb JFET replaced just last June and will include that invoice in the box when I ship it back. Taking that chassis out of the shell is a huge PITA. Each time I have done so, I was very careful to put the reverb connections where they originally were. There isn't a whole lot of slack for either set, but I will definitely double-check those again. I expect to be shipping the amp back to Mesa within the next couple of weeks. I was so hoping it was just a tube issue, but it seems my fears were pretty spot on. I almost wish I got the V:35 instead. But, I wanted the full versatility of the V:90 and I gambled on used gear. Plus, the price was less than a new V:35. Now, I think I know why! In the end, even after all new tubes and a Mesa factory repair, I will still be in an acceptable price range, but the time lost is what bothers me the most. I wanted to be using this amp in the handful of gigs I have left for this year. My TC-50 is handling those for now, which isn't bad at all, either.

I got my new order of all Mesa tubes. While changing them, I sprayed the RadioShack version of Deoxit on each tube socket. I don't know if it was the spray or just using Mesa branded tubes, but I now believe I have the full gain the amp is supposed to have. On Ch 3, either in IIC+ or Mk IV mode, I have plenty of gain on tap. Extreme mode causes quite a volume bump, and I can't say I find that mode too useful yet, but I am waiting for the tubes to cool off so I can try the AT7 mod. I was pretty bummed about this for quite a while and I am now feeling a very good sense of relief. To the Mark's credit, I have been used to the TC50's level of gain, which is a bit more than the V, so there really isn't a fair comparison between the 2, but now my V sings like I feel it is supposed to. Unfortunately, the only cab I had nearby was my Eminence Swamp Thang, and I can't say I feel the V and that speaker are a good combo. I may have to break out my RK cab and run the amp through its paces after I install the AT7 in V4. Sofa king much happier now! Way better to spend a little over 200 on new tubes, than to pay that much in a guestimated repair and not have the amp for a while.

Is the AT7 to go in V6 or V4? I thought it was V6?

BoogieHog said:

Is the AT7 to go in V6 or V4? I thought it was V6?

Click to expand...

Either produce good results. V6 is more subtle, just a slight taming of the high end but on all three channels (but not effect in LOOP BYPASS).

V4 actually changes the gain structure of Channel 3 a bit more while taming it, but only affects Channel 3 and works with Loop Bypassed as well.

jnoel64, I'd wager that the deoxit did the trick, or just one of those old tubes happened to be faulty in both sets. You can always swap some back now to test yourself.

I tried the AT7 in V4 only. I really need to use a different speaker; I just didn't want to drag one to the basement that late. But, mostly what I noticed was a slight drop in gain. The Swamp Thang didn't really produce much of a tonal difference to my ears. But, then, I didn't crank it up too much beyond bedroom levels. I've thought about putting the JAN/Phillips in both V4 and V6 as well as an NOS Chinese in V2. What I really don't want to do is pull the chassis from the shell again. Ugh. Do all V's have that bolt to support the output transformer? Having the reverb tank exposed beneath the shell is an odd thing as well. Why not just make the shell a bit taller? Anyway, finally getting to hear the V roar with all its testicles was a real relief and pleasure. In about a month I will have my house all to myself and I hope to push the amp harder and really hear its full glory.