Mark III and IIc+ differences

Hi,
Has anybody here compared a Mark III and IIc+ directly? What are the differences between the two amps concerning the settings? Is it true that the mark III has more gain and what knobs react differently?

so far,
ahoi

This has been an almost endless debate. Here is my take, if you can't find or afford a IIC+, then a MK III will do. It is almost 98% the same circuit, but it uses a different PC board and output transformer. With that being said, I am not a beliver that the the III is identical to the IIC+. The III does not have more gain. Some say it has too much sizzle which can translate into seeming to have more gain. I find the MK III to be close, but no cuban cigar. Both amps need a graphic EQ regardless and I would not pesonally buy any onther power amp than a simul-class.
I think the power transformer, componentry and PCB layout and design lead to a slightly different sound from the MK III. The same goes for a MK IV, but I find the MK IV to be closer than the III to the IIC+. It's way smoother.

You may also benefit from the fact that not all IIC+'s sound the same either, but they all share the same PCB, PT and OT.

My opinion is based on my 3 Simul-EQ-Reverb IIC+s and my 1993 MK IV.


I have been having fun tweaking a two day old Road King to see how close it comes to a IIC+ and I am getting close.


Best of luck.

About the mark IV i heard the opposite. It should be a bit rawer than the III or the IIc+... . I definetely have to check a mark IV if i get my hands on one . Its much more versatile with seperated treble control and fx loop switching, it would have everything i need feature wise.
I already knew the differences you described. The question was more about the way the amps react to the knobs. The quad for example has a mark III and a mark IIC+ Channel which are described as being different to dial in (concerning vol 1 for example). I wonder if anyone here who a/b ed a IIc+ and a mark III made similar experiences ?

besides i already own a mark III red stripe and i am really happy about this amp - i would never sell this amp unless i find a mark IV that is as good in tone and feel

... and concerning the road king : it has very cool features. I like the the idea of having 4 channels, but it must be really heavy to carry, incredibly loud and quite expensive :shock:

There are different versions of the MK IV as well. Mesa always tinkered with the amps. I have heard of brash or raw MK IV's. I must not have one. It is a
12/93 amp in the 6800 range and is a pure work of art and sound. I run GT
6L6 GE's and GT 6CA7's as well as a GT 12AZ7M in the V1 and V5. The rest are Ruby 9th gen. Chinese 12AX7's. I run this setup on my IIC+ head and seemed to tame it down a bit. Out of the three IIC+'s the head had so much natural gain it was scary. The other tow have a perfect balance of gain, but I enjoy running the same preamp tube configuration, but with different power tubes.

If your red stipe is a great tone monster and not too brash, i would say you are as close as you can get to the real thing without a home equity loan.


Enjoy!!!

The Road King head is way lighter than any IIC+ or MK IV combo. The local GC discontinued it from stock and I nabbed it new for $1699.00.

I was a real pig for IIC+'s for a long time. I went through around 12 or so of them over the years. I was really crazy about the 100 watters. They are great amps. On a whim I bought an early MKIII simul. I got it super cheap so I figured why not. Anyway I sent it to Mike B. at Boogie. He did his thing to it. I like to call it a MK IIIC+. For me this is the ultimate amp. I like it better than IIC+'s I owned. I still have a 60 watt IIC+. I currently own 3 MK IIIC+'s. So I'm still a pig for Boogies. While I believe the MK IIC+ is great classic amp. The MK III is a **** fine machine as well. Especially when fine tuned by Mike B.

The 100 Watters actually had less gain due to a circuit mod. You could open the treble up more and let er' rip. With the Simul IIC's and III's there is a cap missing from the gain stages. Go figure. I was very pleased ay how nice the MK IV copped the IIC+ vibe and I am very pleased at the Road King using the 6L6/EL34 combination. It is amazingly similar the the IIC+. I may actually nail it. I replace the V1 and V5 with the GT 12AX7M and it was a dramatic impovement. I do not mind the russian 12AX7's in the loop or gain stages either.

Take care.

Alot of the gain on a III is in the power amp, a IIC+ is all pre-amp.. The IIC+ is a smoother gain, so you'll find that comparing settings to get the same tone, you'll run the III at lower treble settings, and lower presence..
You then will lose some gain compared to the IIC+, so the lead drive will be set higher, and you'll need to pull the middle, or R2 knob, to add gain and smoothness. I can get super close to a IIC+ with my blue striper, but it still doesn't get all the way there. But the tone is 99% there... I actually like the III just as much as the IIC+, but it's just not as collectable...
I play the crap out of mine, and it serves me well. I use all 3 channels, and change my settings alot for different songs. I'm not a collector. I'll put my Mark III and thieles against any IIC+ in a tone war, and listeners will never hear the difference......But when a guitarist A B's the 2 amps, they will FEEL the difference, and that's about it...
ax. :twisted:

"Alot of the gain on a III is in the power amp, a IIC+ is all pre-amp."

Doesn´t that depend on simulclass ? If its simulclass, then you have to get the tubes in class A working. If not, its only the preamp ... ?

... btw : Hi Axe ! I just migrated here from the Mesa boogie amp forum

axwielding1 said:

Alot of the gain on a III is in the power amp, a IIC+ is all pre-amp.. The IIC+ is a smoother gain, so you'll find that comparing settings to get the same tone, you'll run the III at lower treble settings, and lower presence..
You then will lose some gain compared to the IIC+, so the lead drive will be set higher, and you'll need to pull the middle, or R2 knob, to add gain and smoothness. I can get super close to a IIC+ with my blue striper, but it still doesn't get all the way there. But the tone is 99% there... I actually like the III just as much as the IIC+, but it's just not as collectable...
I play the crap out of mine, and it serves me well. I use all 3 channels, and change my settings alot for different songs. I'm not a collector. I'll put my Mark III and thieles against any IIC+ in a tone war, and listeners will never hear the difference......But when a guitarist A B's the 2 amps, they will FEEL the difference, and that's about it...
ax. :twisted:

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I could not disagree more. If the general public did not notice that the MK III was not a IIC+, then Mesa sure did and it took five attemps to duplicate
it. There has not been since, and will probably never be an exact duplicate that is " spot on". After 22 years I can hear the difference from a mile away.

I've never owned a IIC+ but I have a Mark III blue stripe and I can get close to most of the tones I've heard come from a IIC+. I have played a IV and IMO, the III just sounds tighter to me. My III has more than enough gain, I don't even have the lead drive set past 2.5.

What was Mesa's intentions when they redesigned the MK II into the Mk III? Usually a manufacturer is trying to move their product in some direction. They might just want to add features or make it cheaper. I don't have any experience with the MK III.

The addition of Rhythm 2 was the main thing. This allowed for 3 levels of gain. Rhy. 1 is clean, Rhy. 2 provides a dirtier rhythm, (or crunch rhythm as they called it) and lead which can have lots of gain. MK II's had only Rhy. 1 and Lead.

Most of these over processed clips of the IIC+ are way off of what the amp can really do. I can do a clip on my Imac G5 with garage band and amplitube and feed it to you as a IIC+. I never found clips to be a reliable source for an amps true tone. There are too many EQ and processing variables. To be honest, the more I tweak the Road King on Channel 3 Vintage with the 2 6L6/ 2 EL34 power amp, the more I hear the IIC+. I have always found the MK III to just have too much attack and sizzle. The componentry is 98% the same, but the board itself and the layout can have effects on the overall tone of an amp. As well as the PT. The whole stripe debacle is a mess. Hence, I do not own or will probably ever buy a MK III. With the opportunity to buy any amp I want, I have passed on the MK III many times, but what suits me may not suit you. Everyone has their right to their opinion regarding the MK III being so close to the C+, but I have trouble getting three IIC+'s to sound identical. Could you imagine 10,000 MK III's and 5 different variations. The only amp that has ever trully been a dissapointment was the Diezel VH-4. I sold it three months after I bought it and was happier with a three channel Dual Rectifier. I find the Road King can hang with the VH-4 all day. I have been at this tube amp thing since I was 12 and have been cursed with Eric Johnsonitis. An ultra picky tone ***** with ears that catch certain nuances that I either hate or love. I find that the MK III is a good amp, but not a IIC+. For my normal every day amp I find the MK IV to get me where I want to go and mine at least to my ears does the IIC+ very, very well.

I would have to concur with many of your comments. Especially about the clips found on the internet. They are better than nothing, but not much better.
Although I have found that MK III's work best for me. All of mine have been tweaked by Mike B. at Boogie. So at this point I don't think I have a good grasp of what a stock MK III sounds like. Maybe I wouldn't like it. But I sure like the one's I have.

I have to agree with your Mike B modded III. Mike B. was not the designer of the IIC, but he was the person who modified the circuit to become the IIC+. The glory is all his. He tweaked it in late '83 while Randy Smith was in Germany at the Musikmesse. Mike and Doug West got together and tweaked the circuit and the rest is history. If you get a MK III into Mike's hands, he knows how to get it as close as humanly possible to the IIC+. He can recall these amps down to the resistor!!!
The thing that gets me has always been the differences in the componentry used on the MKIIC+ and the MK III. On the IIC+'s alone I have seen so many amps with resistors of different makes and compositions. On my three IIC+'s, the plate load resistors on one are carbon film, another carbon film from a different manufacturer and one with metal film. The same goes for the coupling caps. Some are Sprague and some are Mallory and either could be 715P or 225P all over the amp.
Even Mike B. knows that using a 225P to feed the power tubes will give you a rounder tone. My newest IIC+ has these, yet has more gain than the other two!!! The taper of the pots are all over the place as well. The master pot got so bad Mike modded the circuit and added the 22K resistor in series with the output just to cool it off. The earlier IIC+'s do not have this, and I find the the master volume to work much better. It does not kill your cat at 2. On my three with all the same type, tested preamp tubes and running the identical power tubes from the same batch ( GT6L6GE/GT6CA7GE) each one sounds different. The oldest one with the good master pot and no series resistor is smooth with a ton of gain and has a singing quality. The middle one has superb gain, yet is more detailed and clear with a bit of sting. The newest head has so much gain it is ridiculous and has the attack of a Zulu tribe on Acid. The MK III has the same deal. I have seen a hundred PCB's and there are the same component issues on almost every one. Whatever was on the shelf, or on sale at the time is what was used. The MK III and IV were however more consitent in using metal film resistors on the lead mode gain stages.

Ooops, time for my Klonopin.