Mesa MarkV / Saturation 'mod'

[Wayno]

Been busy with the soldering iron today :twisted: and i'm happy to report no drama's 8)

The Mark V is now even more of a beast!

Done a straight jumper (wire not resistor) on the same lines as Bandits V6a cathode mod. All modes on ch3 are beefier now, iiC+ is much closer to what it should be,well how i would run it on a real iiC+ anyway. iV is like Bandit said "insane" and Extreme just rips your face off even more than it already did. Not sure whether or not i'm going to play with the EQ coupling cap yet as i like the clear difference between the modes that i have at the moment. We'll see. For now i'm very happy.

I have a naff quality phone recording to put up in a mo so i welcome your feedback.

Mods i have installed;

V4 Jan GE AT7
C39 removed
V6A Cathode caps jumped

Tubes as follows;

V1 Tungsol
V2 Stock Mesa
V3 Stock Mesa
V4 Jan GE 12AT7
V5 Stock Mesa
V6 Stock Mesa
V7 Sovtek LPS
V8-11 JJ EL34ii

Thought i'd go back to pretty much stock for recording a little clip so as to give a pretty standard result rather than having a concoction of different tubes in there.

Also been thinking further about the Caps on V1a cathode but have been leaning towards the mindset that adding more low end to the first stage is probably going to overload the bass response too early and just result in flub. After reading the following post in this thread ( http://www.forum.grailtone.com/viewtopic.php?f=3&t=67396 ) it reaffirmed my suspicions,

From Chipaudette;

"In both cases, the bass shift and pull deep knobs connect a capacitor into the circuit. So, with the knob pushed in, the capacitors are not in the circuit (ie, they have no effect) and with the knob pulled out, the capacitors in are in the circuit (ie, they do have an effect).

In both cases, the capacitor is being added to the "cathode" portion of each tube. You'll note that in both cases there is also a resistor and a small capacitor already connecting between the tube's cathode pin and ground. This resistor and capacitor control the low-frequency roll-off of that gain stage. The small value of the capacitor means that (when the knob is pushed in) the low frequencies are attenuated.

When you pull the knob, it brings the bigger valued capacitor. This pushes the low-frequency roll-off of that gain stage to be much lower (way lower) in frequency. As a result, the bass is stronger and deeper.

In the case of the "Pull Shift" on the bass knob, pulling the knob makes this part of the circuit look like the corresponding portion of a classic blackface Fender from the 60s (e.g. Deluxe Reverb or Twin Reverb), which is what the Mark series was originally based on.

Mesa decided to alter this part of the circuit because, with all that bass, the Boogie's overdriven lead sound was too flabby for some people. Therefore, by switching to a smaller cathode cap, it removed some bass prior to the lead circuit, which made the lead sound more smooth. For those who still wanted the Fender clean sound, the gave you "Pull Shift" to be able to bring that deep bass back into the sound, if you wanted.

In the case of the "Pull Deep" knob, this is doing exactly the same trick, but it happens to occur after the effects loop (which is also after the lead circuit). Being after the lead circuit, it does not have the same "flabby / not-flabby" effect on the lead tone. Here, its effect on the bass is simply a matter of whether you like more low-mids and bass frequencies or whether you like less. Do you like beefy girth, or do you like a more focused and slicing sound? It's your call.

Chip"

So in effect i have the Pull Deep engaged on all modes of ch3 with the V6a cathode jumper mod. Pull Shift activates the bigger cap on V1a which is what i was considering before. Think i'll leave that one alone. Maybe the Jfet there (J175A) is what gets switched in between Clean and Fat modes on Ch1 maybe?

DO NOT attempt this if you are not familiar with valve/tube amps and the very real danger of electrocution and DEATH. DO NOT attempt this if you are not comfortable with soldering on tightly populated circuit boards. If you are not comfortable with either as mentioned before but still want the mods done, get a tech to do it for you.

 

[Wayno]

Hey Bandit,

Which hosting site do you use to post pics on here. Mine not working for some reason.

Thanks,

Wayne.

 

[Wayno]

https://soundcloud.com/waynogeoff/mark-v-v4-at7-c39-v6a-cathode-caps-jumper

Excuse the crap playing (very cold in my garage disclaimer) and the crap quality (very cold in my garage which burst a water pipe and destroyed my recording PC ). Used my crappy phone mic to record direct in front about 4' away. The treble keeps dropping out and the bass is distorting but the raw aggression is still there!

Also please excuse the really poor effort at Master at the end, can't believe i forgot how to play that one!!!

Anyway, there's two parts, "Aerials" and "Holier than thou" each played through once in all three modes in order, iiC+ then iV then Extreme. Dropped the master volume on Extreme just to keep the levels similar.

This quote again from Chipaudette explains whats going on with the V6a cathode bypass caps,

As BB said, the "Pull Deep" affects the frequency response of one of the tube stages in the preamp. For the IIC+, it affects the response of the tube stage that is right after the effects loop before the signal heads off to the GEQ and the power amp.

Here's the change in frequency response of this last tube stage with and without the Pull Deep...

http://www.flickr.com/photos/50442673@N03/4629417552/

So, it's interesting to note that, when "Pull Deep" is not engaged (ie, the knob is pushed) that last gain stage actually boosts the treble frequencies more than the bass frequencies. Then, when you engage the "pull deep", the low frequency response of the stage is restored, which makes it feel like the bass has been boosted. But really, the "Pull Deep" simply restores the naturally flat response of that gain stage.

It's also important to note that the boost by the "Pull Deep" isn't actually that large. To recreate the "Pull Deep" you only need to boost the low frequencies about 5.5 dB. Your graphic eq pedal might do +/- 15 dB. Therefore, you don't need to go rail-to-rail with your EQ pedal to simulate "Pull Deep"...unless you really dig the sound!

Chip

 

[bandit2013]

Hey Bandit,

Which hosting site do you use to post pics on here. Mine not working for some reason.

Thanks,

Wayne.

Wayno,
I am using flicker. Cost nothing. No adds to screw with you and allows you to share pictures anywhere.

Actually sharing an image is much easier. Click on the share icon and Ctrl-C and then Ctrl-V. Then delete everything before the "[img" and after"img]" bingo, image appears once you submit. easy. Flicker is tricky but once you figure it out it is not too bad. Even has an editor that I used to add the text and hand drawn arrows as well as crop. Download picture, winds up in cameraroll, select and choose make public and then add to an album. I do not have to wait for the adds to disappear or that crap that photo bucket has turned into. What is the point of that mess anyways. Flicker is much better.

 

[bandit2013]

Here is another version (photo edit) that is the same thing. I blurred out the resistor I used as a jumper so one does not think that is required. Jumper wire represented as a red line. Connect the two capacitors as shown. This will be tricky but can be done with some care. This also may be easier to do as the via I used with the resistor may require a bit more practice with the solder iron before attempting. Also it is best to fit and pre-bend your parts before soldering as is the case with the resistor method I used. The jumper wire method will do the same thing. Also note: if you disconnect anything in the amp such as a wire harness or ribbon cable assembly, do not forget to re-connect it.

I should still continue to make this statement: Please do not attempt to modify your amplifier if you do not have the sufficient skills to do so. If you cannot use a multi-meter or do not know what one is, do not do this period. Before making any attempt to change your amp, understand what it is you are doing. Do not just assume what is shown will be the same for you. I personally had to determine what components are connected where.... the schematic was helpful but also had to confirm that the components in question were actually connected to the V6A cathode using a multi-meter as a continuity test. If the devices on the board lust look like things to you without understanding what they are do not go any further as you probably should not have opened up the chassis in the first place. This or any mod even if it is to replace a bad part with a new one will void your warranty.

 

[bandit2013]

I just realized this thread has been derailed, sort of. It is not required to modify your amp in such a manner. Most of this was experimental and had some good results.

The 12AT7 in V4 or V6 may all you need to make you happy. After all, that does not require you to remove the chassis or use a soldering iron. Some of you may not even need to have the 12AT7 so it would probably be no point doing other things to your amp.

I personally have been disappointed with my Mark V as it has undesirable characteristics that I found to be useless and not musical. Basically CH3 was an ice pick generator that was not pleasing to listen too. If you love how CH3 sounds there would be no harm to try the 12AT7 if you so wonder what the change will sound like. I would not go any further into making changes to the actual preamp. I do not care if the Mark V does not sound like a IIC+ or a MKIV. If it sounds good leave it alone. I would also consider selling or trading the Mark V for something else you may find more desirable. I already have other Mesa amps so to me making a change here or there was a learning experience. It the end result was that impressive I have posted such findings and what I did to achieve that. Mods are at your own risk. You must also understand what it is you are doing, what that change is, what area is affected and confirm that parts are what they are before attempting any such activity. The Mark V was not designed to be a tinker's amp by any means. It is heavily populated, tight spaced and compact in design on purpose. This is not an easy amp to work on. Be smart, play it safe and consult a technician for advice and or service work. Odd things can happen if you make a mistake or solder to something that should not be connected together. Sure it may look or appear simple but it is not. MOST IMPORTANT: BE AWARE THAT MODIFICATIONS TO A HIGH INTERNAL VOLTAGE PRODUCT SUCH AS A TUBE AMP COULD POSSIBLY RENDER THE DEVICE DANGEROUS TO USE IN A SAFE MANNER. ACCIDENTAL CONNECTIONS FROM HIGH VOLTAGE TO ANY INTENTIONAL LOW VOLTAGE CIRCUIT COULD RESULT IN ELECTRIC SHOCK, FIRE, OR LOSS OF LIFE. AND THE USUAL STATEMENT: LARGE CAPACITORS WILL STORE ELECTRICAL ENERGY AND CAN LEAD TO ELECTRIC SHOCK OR WORSE EVEN WHEN THE AC CORD IS UNPLUGGED.

 

[Wayno]

Thanks Bandit.

Here's my jumper mod.

 

[bandit2013]

Sorry if this comment goes against the grain. I personally feel the Mark V was the worse one ever produced. Other than the Edge mode on CH2, the rest of that channel is ok. CH1 is a bit noisy (low level hum, not to mention the tube sing or rattle with lower frequency notes but that may be common with Simul Class amps as the Mark III and Mark IV had that same thing going with reduced level playing, if you have or had one of those you know that is not easy to do as those just go from quiet to blistering loud in a fraction of a turn on the master volume control). Just the other night I plugged in the Mark V to the OS Recto 412 and was playing for a bit. Not bad but then I decided to get into lead mode. Playing notes on the High E string past the 12th fret was unbearable. I still have the ice pick tone even after the mods. I believe this has more to do with the tone stack for CH3 than the over drive circuit composed of V5A and V4B. However, due to design, V4B has the highest gain factor for the upper frequencies. But yet that same identical circuit is used going back to the IIC+, it is identical in the Mark III and Mark IV. I would like to be able to get away from the 12AT7 in V4. Other changes in the Mark V that differ greatly from its predecessors is the tone stack design. The 2009's had a different tone stack or shall I say a different RC network used as a bright boost bypass. 2010 they changed that due to complaints and extremely brittle tone. However, the IIC+, III and IV have a few differences to the Mark V. For starters, there is no bright bypass network to shunt part of the voltage divider that feeds into V1B. Actually those early models use a 1Meg ohm pot (volume control) to feed into the second gain stage. Also there is a 10Meg resistor between the 750pF and 250pF along with a switch to bypass the 10M resistor. Not sure if that is the issue here. But the bright bypass cap that bypasses the upper portion of the voltage divider is not part of the original designs. Time to experiment and see if I can warm up the amp. May just cut a lead on the 82k resistor or cut the cap out. For the 2009's perhaps removal of the brightness cap C18 would do the trick. 2010 and following has the C18 remapped so it ties into the treble control and couples to the output of the voltage divider through a series resistor of 82k. Adding a series resistor to the 750pF cap may be a bit more difficult. (was thinking of installing a 1Meg resistor). I know the bright cap is there as I have found it. I wonder if the newer one's are any different than my 2012 model. I personally did not buy this amp to cut into it. I just want to play though it and enjoy but why does is sound so brittle? Time to find my tools to get started and see what happens. Before I forget, was it the blue wire or the red wire? Do I cut both? :roll: It should not explode so no drama here, but just to be safe I should remove the C4 (not regarding C4 on the PCB as that should stay there or your clean channel will not sound too good with just bass and midrange.

 

[bandit2013]

Just a warnig.....do not do this. void warranty. electrocution. death. and the "you need to be technically skilled to so any particular work on a device as a tube amp". No pictures today. No soldering required so lifted traces or blobs of solder landing on the PCB to cause more trouble. No ribbon connectors to remove (remember to return those you did take out :roll: I am guilty of this myself). Oh yeah, one last note: if you are not having ice pick woes with CH3 this is not for you. If you are, this may help.....

I had thought about changing the slope resistor on the tone stack but easier said than done. It is possible to do such but may be easier to tack on a resistor in parallel to alter the slope resistor. However, this is not about that component but something different. I did have to review all of the schematics once more to confirm my eyes were not deceiving me. Still no clue to the Mark V tone compared to the rest, it could be related to the fixed voltage divider vs the 1meg pot used as a early volume control. Not quite the mod I would consider. I gave up so I cut both wires (reference to my last post if you want to make sense of the comment), boom! well not exactly but I did cut two wires or leads. Also have to slice though some blob of glue to remove the cap. Yep. C18 is no longer in my amp, gone, kaput, fizzed out and the dog ate it. He found something stuck in the carpet. That too will pass (I hope). The truth is I put it in the garbage and the dog did not eat it, it may have been my guitar pick I was looking for when I was tube rolling the Mark V. C18 appeared to be the lesser of two evils and easier to replace if I had to put it back. That definitely broke the ice down some (will tell immediately if the ice is gone for good once I move the amp into the studio and hook up to the OS Recto 412 loaded with V30s). Actually that sounded better than I thought it would. Messed around with some preamp tubes to find the best combination. 12AT7 still in V4. Everything else is Mesa stock. Played quite a bit with my a humbucker equipped guitar, both bridge and neck positions. Top end is much better, more creamy than icy. Amp still has plenty of bite to break though the mix. Even up on the neck above the 12th fret I could hear music in my ear and not breaking glass. Now for the acid test, the Strat that gave me grief yesterday. Sounded quite similar to the other guitar but more strat like. Did I break the ice and warmed it up a bit. Probably. Will be able to determine once I hook up to the 412 cab. Amp is more musical and vocal. Also seems that the dynamics improved a bit. That may have always been there and never have noticed but quite similar to the JP on using the guitar volume. I can't think of anything else that would make the amp sound any better.... except for new tubes.

 

[bandit2013]

Result is in after carrying the Mark V combo to the other room. It sounded great through a stock OS Recto slant front 412 cab. However one thing I did notice a bit more with the 412 when compared to the horizontal 212 cab, note definition of the upper strings was not as apparent. Not sure if it really was in the first place. Could be the 12AT7 in V4. Will have to give it another round with a 12AX7 instead. Could have easily just change the slope resistor by soldering another onto the 100k to adjust the tone stack. As for now it is stock. The 12AX7 should bring out more top end if it is needed. At least I did not hear any glass breaking in my ears when I ran the Dave Murray strat into the Mark V. All three voices with and without the bright switch.

 

[bandit2013]

Well the Mark V combo has good balance with the installed EV speaker. So far the C18 mod improved the amp for me anyway. It does depend on what guitar I am using though. The Strat with the hot rails may need some pickup adjustments. I would say that hot rails bridge is not my favorite pickup for an Alder body strat. Sounded better with Limba body Carvin Bolt (which is strat like). Any how, since I have a trembucker sized Pearly gates in limba bodied guitar, there is plenty of tope end chime. Also sounded great with mahogany set neck guitar with humbuckers. I was considering restoring the C18 and change the 82k to a higher value but for now it will remain as is, no C18. For those with the 2009 model, just remove C18 and no more ice pick. The rest of the preamp should be the same as the 2010 + model. This is the first time I actually enjoyed playing the Mark V though the OS Recto 412 cab for any extended period of time. I did not get tired of it. The pair of EV speakers I have set up (one I the combo) and one in an extension cab sounded really good too. Those EV black labels can be much brighter than the V30 in the OS Recto cab. Bottom end seems to be much tighter than it was before but that is due to the IIC+ mod I did with the jumper resistors to couple the relay contacts in the appropriate circuits. Have not tried the 12AX7 in V4 yet. I still like the 12AT7 there.

 

[mace]

Not sure what to make of all this..other than the quest for perfect tone that one hears in one’s own head. it has been interesting to follow all of these mods on the Mark V, and the motivation to get the amp to perform more like one imagines it. It seems that after each mod, all is better. But alas, after a few days or weeks, the amp is painful and brittle. Next mod and things are great, then brittle again.

I’m thankful for the “tin ear” I have (as opposed to the all hearing “golden ear”, in which the slightest nuanced change in tone sounds abhorrent) and after putting the Jan AT7 in V4, I couldn’t be happier. What sounded great 6 months ago still sounds great today. I still want to A/B record the original AX7 to AT7 mod someday, just to give a close comparative listen.

Mace

 

[bandit2013]

Not sure what to make of all this..other than the quest for perfect tone that one hears in one’s own head. it has been interesting to follow all of these mods on the Mark V, and the motivation to get the amp to perform more like one imagines it. It seems that after each mod, all is better. But alas, after a few days or weeks, the amp is painful and brittle. Next mod and things are great, then brittle again.

I’m thankful for the “tin ear” I have (as opposed to the all hearing “golden ear”, in which the slightest nuanced change in tone sounds abhorrent) and after putting the Jan AT7 in V4, I couldn’t be happier. What sounded great 6 months ago still sounds great today. I still want to A/B record the original AX7 to AT7 mod someday, just to give a close comparative listen.

Mace

Keep in mind, I do not always use the Mark V. I make changes and it seems better then it sits in the corner of the room unused as I have other amps that hold my interests much longer than the Mark V. I do come back to it and then realize it still is not right. I could just sell it real cheap and get another one as I found more recent builds to have better sound. Last time I played though it was this morning. Sounded just as good as it did the night before. If things are great I will not bother to post. If you prefer, I will end my tone quest with the Mark V and remain silent.

 

[mace]

Keep in mind, I do not always use the Mark V. I make changes and it seems better then it sits in the corner of the room unused as I have other amps that hold my interests much longer than the Mark V. I do come back to it and then realize it still is not right. I could just sell it real cheap and get another one as I found more recent builds to have better sound. Last time I played though it was this morning. Sounded just as good as it did the night before. If things are great I will not bother to post. If you prefer, I will end my tone quest with the Mark V and remain silent.

Don’t misunderstand me! I love the insights and info you have on these things. Keep the info coming! For example, I never would’ve checked out the vertical 2x12 without your positive comments...and it is by far my favorite cab now!

My point was, I really am happy with the Mark V with the V4 mod (your idea, based on Apeman’s V6 mod). Again, your insights have helped! Hope someday you’ll find peace with that Mark V of yours.

 

[bandit2013]

That my friend has come. I actually love the Mark V now. Too bad I had to go through all that to get there. I would have to say one thing positive about the Mark V as I believe it has the most perceived gain that Mesa has made thus far. It has all of the character of the JP-2C and more, and it even goes beyond the TC-50 or TC-100. One thing I did not expect was a tighter bass response. Not sure if that is due in part to the 12AT7 in V4 or the IIC+ mod I did that many others have been discussing else where. Taking out the bright cap on the tone stack improved the upper frequency response a bit and yet may have retarded some too. Will have to compare the Mark V to my other amps. Actually I was playing though it last night and then the Roadster (dang is that a fine amp with the right preamp tubes in it to cure the bottom drone). I can finally say I am impressed with the Mark V. It may not sound like the stock amp due to the changes (minor as they are). Basic tone is still there and it sounds much like a Mark series amp should sound like. My next post will be how much I hate the amp and the reason why it sits in a corner and does not get used in favor of the JP-2C or the TC-100. Honestly I hope those days are past me now. I so much wanted to rave about this amp as much as anyone else. Now I think I can. Done with mods, all I want to do is play the guitar. I am tired of chasing the tone balloon with this amp.

 

[sherrillsml]

Bandit, I too seem to experience a little brittleness still yet with the V I purchased new in 2010 though the AT7 in V4 has made this a much better amp for me. Could you post a short summary of each mod you have made to date? I dont want to wade thru the greater than 600 posts to weed out the mods you have performed. Detail is not necessary. Thanks!

 

[bandit2013]

Bandit, I too seem to experience a little brittleness still yet with the V I purchased new in 2010 though the AT7 in V4 has made this a much better amp for me. Could you post a short summary of each mod you have made to date? I dont want to wade thru the greater than 600 posts to weed out the mods you have performed. Detail is not necessary. Thanks!

You asked for it.... this may be a long one but will try to keep it short.

First mod was experimenting with the 12AT7 in V4 and or V6 using only stock tubes in all other positions. Yes, you need to check other channels character with the FX loop active to confirm this is for you when using 12AT7 in V6.

Related but way off topic as the following is actual circuit mods: I have to include this with any circuit mods as some that may read this may think "sure I can do this". Please regard doing this with care, Do be aware there is the potential to be electrocuted by the amp even with the power chord removed. High voltage may be present on the power supply capacitors that could result in electric shock, burns, or death. Always wear eye protection when sticking your face into an amp. Always confirm that the stored energy in the large electrolytic caps has drained properly. Do not short the terminals of the capacitors. There are built in bleed resistors on the circuit so give it time to drain the stored energy. Some of the mods may require you to remove some of the ribbon cable connectors for better access. Be careful when removing them as damage to the wires is possible. Also they must be returned to their original position (confirm that the cable is connected properly, i.e. the housing is sitting over all the pins on the header). Always take pictures of the amp in its original state especially if you need to remove something you can put it back where it belongs before powering up the amp after modifications. Use of a volt meter, solder iron and having knowledge of the innards of a tube amp, know what you can touch and what you should avoid! DO THIS AT YOUR OWN RISK!

These are in order of what I did. Does not mean it is mandatory to follow the same order.

First circuit mod: Removed C39, result was brighter tone but increased upper midrange. it did cut some ice out but not entirely. The cap is unessential really but it does effect the tone to some extent by cutting the upper mids and treble from V5A drive circuit. (Do this one last if you decide to cut anything out, this one is most difficult to remove and to return to stock due to space constraints).

Second circuit mod: Added a 150 ohm resistor jumper to couple the negative terminals of C42 and C106. What I have also tried was a 15 ohm 1/4W resistor as the leads are small. A jumper can be used but I found the small resistance to work well in my case. Once you locate the area to be altered, shape the leads of the resistor first. Just bend one lead over completely so that both leads of the resistor are pointing in the same direction. You only need 1/8 of an inch or a bit more to insert into the via so cut the lead that was not bent to about that length. The bent lead should be cut approximately at the mid point of the resistor body and then form it out. If the via hole has solder in it, use care when installing the resistor jumper. Solder or tin the lead on the short resistor lead and then add solder to the solder tip, This will help melt the solder in the via and allow you to slip the resistor lead into the hole, do not force it to go it and do not apply too much pressure on the PCB as you can easily damage the via or copper trace on the board. Then solder the formed end to the negative terminal of C42. Do not over blob the part with solder, just enough to couple the leads together. Also try not to get solder everywhere, keep track of what may fall off the solder iron so you can remove it. Good soldering skills are key to success on this mod. However, you may also just add a jumper wire between the two capacitors and not bother with the via (hole). This mod will effect the bass response of IIC+, it will thicken up its character and also increase the gain response of V6A. It also enhances Mark IV mode as well as Extreme. I would have included the other mode but that did not change much if anything at all (jumper resistor to couple the IIC+ and normal voltage dividers on the GEQ ) so I did not include it here.

Resistor jumper mod:

Alternate: jumper wire mod: (note that I blurred out the resistor mod from above)

The last mod I did was to remove C18 (180pF cap) from the tone stack of CH3. Amp will remain bright but not as brittle. This may reduce some clarity or note definition but definitely cut the ice pick out. Not sure if related to the other mods as I did this one last. I would probably start here and do the others later.

 

[bandit2013]

Not sure exactly how long I did the last mod, here is another one..... plug in the guitar and just play. **** does the Mark V sound incredible. Finally I have the amp I wanted..... now the question is do I still need the JP-2C? tough call. The answer is still yes, love that amp for what it is but the Mark V is stepping all over it now. Mark IV voice is more than I can handle. Still bright enough to cut though the heavy mix and does not kill my ears with that annoying tone it used to have. Not sure what mode really matters. C18, should have done that first. There was a definite change in upper midrange tone with C39 too (takes away some of the sterile tone ) The jumper to couple the two caps on V6A circuit is essential. I would call that the IIC+ correction mod. The other IIC+ mod for the GEQ probably not important. I am currently running the Mark V combo with the loaded EVM12L black label speaker and with another in a deep 1x12 cab. Now that is a Mark amp to enjoy. OS Recto 412, ****, I wish I did not convert the Mark V to a combo. Too bad I sold the head shell. May have to consider getting one made as this thing rocks. Yes this means I am finally happy with the Mark V. Oh yeah, on the V6 mod, if your Mark V was sort of on the flubby side or farts a lot, this will definitely cure the loose bottom and tighten it up. One thing for sure, I will not be installing the MC90 into the combo any time soon. To think I used to hate this amp. Now it has more boogie than the JP. Still running with the 12AT7 in V4 as that adds to the mojo of the amp.

 

[bandit2013]

one more thing to boast about.... I believe the second IIC+ mod (GEQ fix) had improved CH2 and CH1. I am loving every aspect of the Mark V since I made the transformation of mods or corrections. I was playing for quite a while last night and did not get tired of the tone or characteristics on any channel. I did not even notice any tube sing or rattle but it was probably there as I was playing quite loud. One happy camper. Uncertain as to what changes may have been made to the current builds, mine is a 2012 so it would include that year or earlier. I have cycled through just about every guitar I have including the three super strats. Not one complaint except that I wish it was a head again vs combo due to the added weight. If Mesa comes out with another Mark version, it would have to top the JP-2C or the modified Mark V for me to want it.

 

[sherrillsml]

Sorry Bandit, I need clarification. You posted "one more thing to boast about.... I believe the second IIC+ mod (GEQ fix) had improved CH2 and CH1". Is this referring to the 3.3k across C49 and C99 mod? Is this a mod that helped in your amp?

My amp was assembled in May of 2010 and I have a feeling we share the same design and problems, and I would hope to get to the point of satisfaction you are at. Thanks again for your patience and excellent help with this matter!