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The REAL Mesa Boogie Mark IIC++

adamdevo

Member
Does anybody know in what consists the Mesa Boogie IIC++ mod ? Can it be reproduced virtually changing some settings ?
From investigation I've done the IIC++ amps floating around have either or both of the following:

A) Push/Pull for Mid
B) Added gain

Pretty sure it's just added gain that most people want though
 

adamdevo

Member
I though the IIC++ was meant to replicate Metallica's early thrash sound, obtained by running the preamp section of a Mesa IIC+ into a Marshall JCM800 power section? Am I missing something here?

This is not true and was never verified. It was a rumour started over one old Metallica pic that had a marshall head in the background. Crunchberries was not slaved in a Marshall power amp.
 

rossipedia

Experienced
I though the IIC++ was meant to replicate Metallica's early thrash sound, obtained by running the preamp section of a Mesa IIC+ into a Marshall JCM800 power section? Am I missing something here?

Straight from James' tech himself:

This model is part of our live sound.
This amp was removed when the new MKII models were added and firmware updated.
I asked if it could be ported for Q3 as I was having a difficult time migrating to the updated firmware and retaining our earlier work.

In theory, you can get the IIC+ and the IIC++ models to sound identical.
 

Clive

Experienced
Pretty sure it's just added gain that most people want though

OK. Which stage is affected by the added gain in the real Mesa Boogie IIC++ ? Volume ? Lead drive ? Lead Master ? Is it more complex than that ? Are there other changes ? Can this be simulated in the Axe ?

Thanks
 

IronSean

Experienced
The "Real" Mark IIC++
The Mesa Boogie Mark IIC++ is a mod done by Mike B of Mesa Boogie on Mesa Mark IIC+ model amps. As others have stated in this thread, this is a mod that adds a lot more input gain, making the clean channel no longer clean and since the clean channel cascades into he lead channel on the IIC+ model adds extra gain there too. Sometimes it was implemented with a push-pull pot on the mid knob which allowed turning the extra gain off and on. Some even postulate this evolved into the Mark III models which had three "channels". Some just had the IIC++ gain always engaged though. James Hetfield of Metallica is widely believed to have had his Crunchberries IIC+ amp modded to IIC++. Only a very small number left the factory this way, and a handful of Metallica fans over the years have had their IIC+'s modded to IIC++ too.

There are rumours this mod just lifts the middle pot from ground which allows more signal to pass through, but I've yet to find someone who had the mod done then did a detailed schematic. I've got a collection of IIC++ gut shots owners were nice enough to send me around somewhere, but since the IIC+ was a mod itself, and the signal wires criss-cross the IIC circuit board it's not the easiest thing to identify by sight alone.

The IIC++ Model
The IIC++ model in the Axe FX actually has nothing to do with the mod at all. In the old days the Axe only had one IIC+ amp model (rather than the 4 variations of bright/deep currently available). Metallica started using the Axe FX for their live sound when that single IIC+ model was the model, and got used to using it for their live sound. M@ has stated he went to Metallica HQ in the past and helped them dial the IIC+ model to match James' Cruchberries acceptably without the need to specifically model James' personal amp.

Then later the IIC+ model was replaced with the 4 variation when Cliff either acquired a IIC+ himself or just decided to re-do the model to add the Bright/Deep switches that were previously missing.

After that the Metallica team reached out to ask for the old model to be returned since they relied on it for their live sound and didn't want to start from scratch on the replacement models. So it was returned as the "Metallica IIC++". It might have been a reference to the IIC++ mod, or just a reference to a second plus being better, or just a reference to the C++ programming language.

Cliff has later stated that just the tapers of the pots are different, but in my testing (using pots at 0 or 10) I've never been able to match the IIC++ to one of the 4 IIC+ models, so I still suspect a bit more is different.

Simulating the IIC++
The most consistent explanation for the mod is increased gain at the input of the amp (as evidenced by the clean channel losing a lot of it's headroom). Using the input trim, input EQ, or natural boost are all ways to cleanly add input level. The input EQ also seems to be altered to cut bass and boost upper mids, which allow the bass and mid knobs to have a larger useful range than stock. (stock you wouldn't want the bass above 2, but with the mod 3-5 can still be OK). So take the input EQ and raise the low cut and create a boost in the upper mids too.
 
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rodzimguitar68

Fractal Fanatic
The "Real" Mark IIC++
So it was returned as the "Metallica IIC++".
Is that model in the Axe FX right now? I just checked the Fractal Wiki and it's not listed. However, there is a note that the amp models are being updated due to Cygnus. I'm trying to determine how recently this Metallica model was put into the Axe.

Thanks

PS - I'm away from my gear at the moment.
 

AJ Vargas

Experienced
Is that model in the Axe FX right now? I just checked the Fractal Wiki and it's not listed. However, there is a note that the amp models are being updated due to Cygnus. I'm trying to determine how recently this Metallica model was put into the Axe.

Thanks

PS - I'm away from my gear at the moment.

IIRC it was introduced back on Quantum 3.XX
 

zenaxe

Fractal Fanatic
The AxeFx c++ was just an old version of the c+ that Cliff restored to the firmware at Hetfields request. This was in response to one the axe II FWs. It is not a model of the Mesa IIc++ or one of James’s amps or anything exotic.

Everyone went briefly crazy over it because of the Metallica connection but it is just another Mesa Mark model. It has plenty enough gain. IMHO.
 

IronSean

Experienced
Is that model in the Axe FX right now? I just checked the Fractal Wiki and it's not listed. However, there is a note that the amp models are being updated due to Cygnus. I'm trying to determine how recently this Metallica model was put into the Axe.

Thanks

PS - I'm away from my gear at the moment.

It's the IIC++ model, it got named more generically somewhere down the line. USA IIC++ is the current name I think?

And you trimmed my quote in a way that made it look like the IIC++ model is of a real IIC++ amp. To be clear this isn't a model of a real IIC++, it's just a legacy version of the IIC+ model named IIC++.
 

Chuck P

Member
The "Real" Mark IIC++
The Mesa Boogie Mark IIC++ is a mod done by Mike B of Mesa Boogie

The IIC++ Model
The IIC++ model in the Axe FX actually has nothing to do with the mod at all.

Simulating the IIC++
The most consistent explanation is increased gain at the input of the amp
Can we replace this entire thread with this post? Thank you @IronSean .
 

Clive

Experienced
From grailtone : http://www.grailtone.com/forum/viewtopic.php?f=38&t=71525

Elpelotero said :

"These are the notes I typed down last year as I spoke to Mike B. when he was doing my amp...

C++ Mod:
• Many people confuse the ++ mod for different things:
o It’s not a Volume 1 mod, that is something else, wherein one of the front ¼” jacks are plugged up to be used as Volume knob for the dirty channel, giving the amp 2 true separate channel volume knobs and a master volume knob.
o It’s not an “R2” mod, to make it more akin to a Mark3, selectable via a push-pull knob. There are some factory C+’s done this way, as this was something Randy and Mike B. were doing almost as a prototype for the Mark3 (which has 3 channels). It basically gives a boost to the clean channel to give it some crunch, essentially turning a C+ into a 3 channel amp of sorts.
o It’s not a Bright Reduction mod, which is very common on Simul heads to help round them out.
o It’s not the Mark 3+ mod, either. This is a mod wherein a Mark3 has some of its specs changed to reflect a C+. It will sound very close, but not 100% like a real C+.
o It is an extra Gain mod, wherein the Bass frequencies are cut out, and there are more upper mids put in. This allows you to dial the Bass and Mid knobs higher than normal (previously from 0 and 2 up to 3, 4, 5, etc). Having the EQ is essential if you do this mod, as it allows you to dial the bass back in that is being sucked out. On a Simul, some of the smooth rounded tone will disappear in favor of a more raw, hairy tone. It is not selectable via a push-pull pot or switch. Once it’s in, it’s in. However, Mike B. is able to remove it and bring the amp back to stock gain."
 

IronSean

Experienced
From grailtone : http://www.grailtone.com/forum/viewtopic.php?f=38&t=71525

Elpelotero said :

"These are the notes I typed down last year as I spoke to Mike B. when he was doing my amp...

C++ Mod:
• Many people confuse the ++ mod for different things:
o It’s not a Volume 1 mod, that is something else, wherein one of the front ¼” jacks are plugged up to be used as Volume knob for the dirty channel, giving the amp 2 true separate channel volume knobs and a master volume knob.
o It’s not an “R2” mod, to make it more akin to a Mark3, selectable via a push-pull knob. There are some factory C+’s done this way, as this was something Randy and Mike B. were doing almost as a prototype for the Mark3 (which has 3 channels). It basically gives a boost to the clean channel to give it some crunch, essentially turning a C+ into a 3 channel amp of sorts.
o It’s not a Bright Reduction mod, which is very common on Simul heads to help round them out.
o It’s not the Mark 3+ mod, either. This is a mod wherein a Mark3 has some of its specs changed to reflect a C+. It will sound very close, but not 100% like a real C+.
o It is an extra Gain mod, wherein the Bass frequencies are cut out, and there are more upper mids put in. This allows you to dial the Bass and Mid knobs higher than normal (previously from 0 and 2 up to 3, 4, 5, etc). Having the EQ is essential if you do this mod, as it allows you to dial the bass back in that is being sucked out. On a Simul, some of the smooth rounded tone will disappear in favor of a more raw, hairy tone. It is not selectable via a push-pull pot or switch. Once it’s in, it’s in. However, Mike B. is able to remove it and bring the amp back to stock gain."

Though later on he stated:
"I talked with Mike again. He reluctantly admitted that there actually were some C++s made with the push/pull mid pot for switching between C+ and C++ modes, even mentioning kippiejr's amp as being among them. He doesn't like telling a lot of people about it because its a very time consuming, pain-in-the-butt job to do, which is why he may have been slightly less than forthcoming about it the last time he and I spoke. The master clearly doesn't want to go there anymore."

So some were indeed switchable too, in a different way than the 3 channel mod was. The EQ tweak is a detail I forgot, as I do remember now it opening up the usable range of the bass knob.

So to replicate, probably you want to boost your high mids and raise the low cut in the input EQ, and boost the gain either there too, with a neutral boost, or with the input trim. Some Leon Todd was already doing to his IIC+ sounds anyway.
 

touch33

Inspired
So, slope and taper are interchangeable terms?
I don’t believe so, no. “Slope” implies a “straight line” whose only variance is the rate at which the start value and end value are reached (linear — like a wedge from low to high). “Taper” generally implies a non-linear (variable) “curved” slope — which could be a pot that’s “fast to reach 80% value then the final 20% comes on more slowly”.
I think...
 

Underwood

New Member
o It is an extra Gain mod, wherein the Bass frequencies are cut out, and there are more upper mids put in. This allows you to dial the Bass and Mid knobs higher than normal (previously from 0 and 2 up to 3, 4, 5, etc). Having the EQ is essential if you do this mod, as it allows you to dial the bass back in that is being sucked out. On a Simul, some of the smooth rounded tone will disappear in favor of a more raw, hairy tone. It is not selectable via a push-pull pot or switch. Once it’s in, it’s in. However, Mike B. is able to remove it and bring the amp back to stock gain."

Interesting. I'm an Axe Fx II user.

With an Axe II, how would you :

- cut out bass frequencies

- boost upper mids (what frequency range)

Would you use a filter block or a PEQ block and how would you set it ?


Thanks guys.
 

rossipedia

Experienced
I don’t believe so, no. “Slope” implies a “straight line” whose only variance is the rate at which the start value and end value are reached (linear — like a wedge from low to high). “Taper” generally implies a non-linear (variable) “curved” slope — which could be a pot that’s “fast to reach 80% value then the final 20% comes on more slowly”.
I think...
You're mostly there, I think. They overlap but they're not identical. A linear taper is a slope, as you've defined it. So "slope" would be one kind of "taper", but other kinds exist.
 

touch33

Inspired
You're mostly there, I think. They overlap but they're not identical. A linear taper is a slope, as you've defined it. So "slope" would be one kind of "taper", but other kinds exist.
Here’s the Wikipedia def:
“In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line.”

More succinctly, slope is always a linear function between two points on an X/Y plot and is the simplest form of taper (known as “constant”). What the OP asked (before this thread went into the mathematical weeds) was if pot taper differences implied more “maximum available” gain (nope). While a non-linear pot “taper” can have a mathematically infinite number of point-to-point slopes within its total range, slope is always a directly linear function.
 

IronSean

Experienced
On a 500K pot, the value at one extreme is always 0 ohms (0 +/-), and the value at the other extreme is 500K (+/- tolerence). Between those two values is where the different tapers come into play, but they always start and stop at the same spot, otherwise it wouldn't be a 500K pot anymore.
 

mr_fender

Axe-Master
Many non-linear pots don't actually have a smooth response curve. Many Logarithmic pots are often approximations of a logarithmic curve using two different linear slopes joined somewhere in the middle. Like this:

potentiometer_taper.png


They are likely much easier (and cheaper) to produce this way and the end result is usually close enough for Rock N' Roll. The actual response largely depends on the specific pot brand, model, etc. in question.
 

rossipedia

Experienced
Here’s the Wikipedia def:
“In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line.”

More succinctly, slope is always a linear function between two points on an X/Y plot and is the simplest form of taper (known as “constant”). What the OP asked (before this thread went into the mathematical weeds) was if pot taper differences implied more “maximum available” gain (nope). While a non-linear pot “taper” can have a mathematically infinite number of point-to-point slopes within its total range, slope is always a directly linear function.
That's a much more accurate way of saying it 🤘
 
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