mark IIc++ (yes two plusses)

[deskman]

when i met petrucci backstage at G3 in sydney
he said that the mark IIC+'s that he has
are actually mark IIc++'s

he said that there was an extra mod done to them by mike bendinelli

anyone know anything about this?

 

[Shep]

hey deskman it's tom SHEP from jp forum and who has a friend who goes to JMC..we both got the mk iv around the same time..

yeah..it's a mod that makes your already nice amp even nicer...boogiebabes is the man to talk to about it as he is most likely the only man other than mike B to know how to do it.he is kinda secretive about how it is done but i think would be willing to say wat it sounds like....

but he got pissed off at some stupid post's on here aimed at him so he doesn't come on here much more..He is a Great guy if you can get on to him and a wealth on knowledge..goodluck

 

[Boogiebabies]

There are a couple of different mods I have noticed and theorized about on JP's amps. The first is a really simple way to add more gain, and different textures of gain. The second is the second Volume 1 which is a mini MK IV pot that is switched in when the lead channel is engaged, thus allowing him to run a clean channel Vol. 1 at 5 and a Lead channel Vol. 1 at whatever he wants. I have tried the dual volume one mod and it works fine. There was a small amount of errant noise, but I am working on getting it quiet. I assume it was the type and length of wiring I was using and basically messy point to point wiring.

It does work very well though.

I have three different versions of the high gain mod, but I need to find the right switch so I can have all three switchable when I want them.
They really make for a versatile amp whether your a blues guy or if you want so much gain it is insane, but controllable. I will work on making them footswitchable later. Not, too hard.

I am still working on the #1 prototype and this guy has put up with being the test subject for a while. After testing a few tones last night, I am sure he will be one happy camper. I was grinning from ear to ear.

 

[axelfatu]

There are a couple of different mods I have noticed and theorized about on JP's amps. The first is a really simple way to add more gain, and different textures of gain. The second is the second Volume 1 which is a mini MK IV pot that is switched in when the lead channel is engaged, thus allowing him to run a clean channel Vol. 1 at 5 and a Lead channel Vol. 1 at whatever he wants. I have tried the dual volume one mod and it works fine. There was a small amount of errant noise, but I am working on getting it quiet. I assume it was the type and length of wiring I was using and basically messy point to point wiring.

It does work very well though.

I have three different versions of the high gain mod, but I need to find the right switch so I can have all three switchable when I want them.
They really make for a versatile amp whether your a blues guy or if you want so much gain it is insane, but controllable. I will work on making them footswitchable later. Not, too hard.

I am still working on the #1 prototype and this guy has put up with being the test subject for a while. After testing a few tones last night, I am sure he will be one happy camper. I was grinning from ear to ear.

Boogiebabies:

Kinda a stupid noob question: since the mod adds significantly more gain, is it still possible that an overdrive pedal can be used to boost some more gain on a stock iic+ to have the same effect?

 

[4nkam]

What about the mod for his graphic EQ that reduces the effect?

 

[Boogiebabies]

There are a couple of different mods I have noticed and theorized about on JP's amps. The first is a really simple way to add more gain, and different textures of gain. The second is the second Volume 1 which is a mini MK IV pot that is switched in when the lead channel is engaged, thus allowing him to run a clean channel Vol. 1 at 5 and a Lead channel Vol. 1 at whatever he wants. I have tried the dual volume one mod and it works fine. There was a small amount of errant noise, but I am working on getting it quiet. I assume it was the type and length of wiring I was using and basically messy point to point wiring.

It does work very well though.

I have three different versions of the high gain mod, but I need to find the right switch so I can have all three switchable when I want them.
They really make for a versatile amp whether your a blues guy or if you want so much gain it is insane, but controllable. I will work on making them footswitchable later. Not, too hard.

I am still working on the #1 prototype and this guy has put up with being the test subject for a while. After testing a few tones last night, I am sure he will be one happy camper. I was grinning from ear to ear.

Boogiebabies:

Kinda a stupid noob question: since the mod adds significantly more gain, is it still possible that an overdrive pedal can be used to boost some more gain on a stock iic+ to have the same effect?

With the two versions of the boost mod, a pedal is not needed. Seriously, not needed on one and another behaves like a boost pedal. It's subtle, but you can easily sense the extra drive.

 

[Boogiebabies]

What about the mod for his graphic EQ that reduces the effect?

I did not know there was one, but I recently stated that the voltages to the graphic over the years has been reduced. Mesa also put a .01 cap on the MK IV before the signal hits the phase inverter to smooth it out. I was just making an example. The IIC+ uses -42.2 volts to the EQ amp. The MK IV uses -23. On the C+ the EQ is fed from the LV tap and the voltage is reversed and dropped by a 470 ohm resistor. It's labeled F. I am interested in the lower voltage, but not that interested. My favorite state of the IIC+ is stock, with the ability to add extra stages of boost and voicing. I just enjoy giving it the ability to do things that it cannot do in stock form, but maintaining usability, not useless fuzz.

 

[4nkam]

Just found the article where he mentions it:

"The C+ has a graphic EQ section that affects everything that goes through it," says Petrucci. "I like a chunky, scooped tone for rhythms, but for leads I prefer a smoother sound, with more mids and less highs. Mark designed this cool little on/off box that adresses this issue--it has a mix control that allows me to reduce the effect of the amp's graphic EQ by as much as I want whenever I switch the box on. It's one of several secret weapons I have that expand my rig's capabilities."

 

[Boogiebabies]

Sounds fine to me. The lower the voltage the less gain the EQ amp will put out. If you put a variable resistor in line with the "F" tap, you can basically tweak the EQ amp. What value the pot would be the research.
I would take a reading on the tap that supplys the EQ amp and try a variable resistor. I would unhook it from the EQ board before I went playing with it. Knowing my dumb *** I would increase the voltage an POOF !!!! :shock:

 

[boogietone]

There are a couple of different mods I have noticed and theorized about on JP's amps. The first is a really simple way to add more gain, and different textures of gain. The second is the second Volume 1 which is a mini MK IV pot that is switched in when the lead channel is engaged, thus allowing him to run a clean channel Vol. 1 at 5 and a Lead channel Vol. 1 at whatever he wants. I have tried the dual volume one mod and it works fine. There was a small amount of errant noise, but I am working on getting it quiet. I assume it was the type and length of wiring I was using and basically messy point to point wiring.

It does work very well though.

I have three different versions of the high gain mod, but I need to find the right switch so I can have all three switchable when I want them.
They really make for a versatile amp whether your a blues guy or if you want so much gain it is insane, but controllable. I will work on making them footswitchable later. Not, too hard.

I am still working on the #1 prototype and this guy has put up with being the test subject for a while. After testing a few tones last night, I am sure he will be one happy camper. I was grinning from ear to ear.

Doe these gain mods work on MKIII's? I'd be very interested in it if does.
Thanks!

 

[Boogiebabies]

I have yet to even think about modding a MK III. I am totally biased to the Green Stripe and have never given it any though. I just think it's perfect the way it is. I do think all MK III's can benefit from an R2 Master Volume, but mine does not bother me either. It would be a while before I sat down and blueprinted the III. The board is totally different and I am much more cautious with the newer style PCB's. It would take a blow torch to ruin a IIC+ board.

 

[Elpelotero]

It would take a blow torch to ruin a IIC+ board.

well that's good news to know.

 

[jvk]

Interesting info boogiebabies, and nice thread.

There are a couple of different mods I have noticed and theorized about on JP's amps. The first is a really simple way to add more gain, and different textures of gain.

I've increased the gain in the MkIVB circuit by increasing the value of the plate resistors on V1a+b and V2a (upto 330k!) and now I'm trying different combinations of cathode resistors and bypass caps. It's difficult to have the plate resistor mod switchable due to the high voltages involved (you don't wanna run 400v through a small switch etc). The increase in gain from using different cathode components is marginal but still usable.

Is your high gain mod also on the cathode/anode resistors (or caps? since you a mention different gain structure, and lower cathode bypass cap = more pronounced mids+highs = more sonic impression of gain etc)

I can't work out anything else to do to this circuit, save another cascading gain stage to squeeze more gain out of it

The second is the second Volume 1 which is a mini MK IV pot that is switched in when the lead channel is engaged, thus allowing him to run a clean channel Vol. 1 at 5 and a Lead channel Vol. 1 at whatever he wants.

So basically this would need a pot to be inserted into the return path from the lead channel, placed before LDR4 to make it switchable when the Lead channel is engaged, right?

 

[boogietone]

I have yet to even think about modding a MK III. I am totally biased to the Green Stripe and have never given it any though. I just think it's perfect the way it is. I do think all MK III's can benefit from an R2 Master Volume, but mine does not bother me either. It would be a while before I sat down and blueprinted the III. The board is totally different and I am much more cautious with the newer style PCB's. It would take a blow torch to ruin a IIC+ board.

Thanks BB!
My MKIII has so much gain already, especially with a pedal in front I seriously doubt I'd know what to do with more anyway.
Thanks again.

 

[Russ]

Wasn't there a mod that they were doing that made a III into a III+?

 

[Russ]

NVM I just saw Reeko's post. I thought that there was a IIIC+ out there...

 

[boogietone]

Wasn't there a mod that they were doing that made a III into a III+?

There is a mod. I almost had it done when I sent my amp in to Mesa not too long ago. I talked it over with a customer service rep but in the end I decided I liked the MKIII just the way it is. If I want a +I'll go buy a IIC+.

 

[Boogiebabies]

Interesting info boogiebabies, and nice thread.

There are a couple of different mods I have noticed and theorized about on JP's amps. The first is a really simple way to add more gain, and different textures of gain.

I've increased the gain in the MkIVB circuit by increasing the value of the plate resistors on V1a+b and V2a (upto 330k!) and now I'm trying different combinations of cathode resistors and bypass caps. It's difficult to have the plate resistor mod switchable due to the high voltages involved (you don't wanna run 400v through a small switch etc). The increase in gain from using different cathode components is marginal but still usable.

Is your high gain mod also on the cathode/anode resistors (or caps? since you a mention different gain structure, and lower cathode bypass cap = more pronounced mids+highs = more sonic impression of gain etc)

I can't work out anything else to do to this circuit, save another cascading gain stage to squeeze more gain out of it

The second is the second Volume 1 which is a mini MK IV pot that is switched in when the lead channel is engaged, thus allowing him to run a clean channel Vol. 1 at 5 and a Lead channel Vol. 1 at whatever he wants.

So basically this would need a pot to be inserted into the return path from the lead channel, placed before LDR4 to make it switchable when the Lead channel is engaged, right?

Are you saying you decreased the plate voltage and got more gain?
The IVB actually lowers the plate voltage to the preamp tubes in R1 and 2 and raises it in the lead mode. There's are great article on plate voltage and cathode values and the effect of bypass caps at www.aikenamps.com under the tech articles advanced section.

The IVB is running lower plate voltages than the IIC+ already. I would increase the plate voltage by using a smaller value series resitor, but I like the B as it is. Depending on the C+ you measure, the V1 on the IV is seeing 38-48 volts less than the C+. So basically your stuck between the Miracle and the Sleeper...

Regarding the dual Volume 1 on a IIC+, no, it does not work off of LDR4.