I restore the thread to those who want it to be just the saturation mod. Besides that, APMAN made a hijack threat..... :shock:
Only way to find out if your amp has the Mesa tone stack fix, you will have to find the extra series resistance on the tone stack...Happy hunting as that circuit board is a jungle and the components in question may not even be on the preamp board....
Mine was signed off on July 16, 2012 (a Monday no less....) I am sure it has the updated tone stack but that did not fix the sterile and vasectomized CH3.
I would agree the Bluestoned that the Crunch mode had the Mojo and CH3 had nogo.
I had played a new Mark V combo when I went to test drive a TC-50 at Russo Music in Hamilton NJ (not plugging the store, it was the closest dealer to me that had more than just one Mesa amp and I live in NC, was on vacation when I went there). That amp sounded great and did not have the tunnel tone of CH3 that my amp has. However the V4 mod is the mojo fix, definitely more hair in the tone department but not the thin 80's tone.
I often wonder If I sold my amp that I have and get another will the same V4 mod do any justice? One does have to question what changes were made since the original release (as is the case with the APMAN re-hijacking the hijacked post, it is all good I hope).
One thing is for sure, I will not be trying the 12AT7 in the JP-2C as I love the amp as is. the Mark V with the V4 change puts it on the same level with more options.
As for the Mark V:35 or 25, I do not believe the IIc+/IV/Extreme has the same tonal character as the Mark V in stock preamp tube format. I just watched one of the videos that showed the settings and thought the Mark V:35 has some great sound to it.
Back to the Big V.... Here is a test for you non believers.... Turn the amp on full power, use pentode mode on CH3, set to Extreme, Set the top row to noon, treble and mids to noon and drop the bass. Bright switch to on, EQ set to preset and play a D chord or any bright chord. If you do not get the broken glass effect from the speakers ( it could be your speakers.....what you may need is an OS Recto 412 with V30, heck even loaded with EV has the same effect). Not a pleasing experience. However with the V4 change to 12AT7 I can play with that all day and even add more treble and presence (sure they are relative to the sum of the cascaded gain stages). Also if you find yourself using only CH1 and CH2 and not much of CH3, you will change your mind once you try it. It is not about the level of gain that matters, the articulated detail of every note and of course the tonal temper of the grind on a chord ring out is just amazing. Sustain, yep it is quite vocal and reactive. If you need more edge try a JAN/GE 5751 but if you have tried the JAN/Phillips 12AT7 it will be hard to make a change. The side effect is not that dramatic and you may even find the tone similar with the stock tube however at higher volume levels the tone will shift and the amp will become brighter and brighter and loss of lower half of the midrange due to cancelling ending up with sterile unusable tone. V4 maintains the stability of the gain stages and you do not loose content across the frequency band of the guitar. No brittleness at all but the tone is still intact and plenty of cut though the mix. Sure the 5751 will give you a bit more top end cut. Take your pick, hit some strings and enjoy the full potential of the Mark V. .....bla...bla....bla....bla..... I better shut up now.