Who knows Mesa power???

Exo-metal

Well-known member
Can anyone tell me here if the power section of a Mesa MKIIb is the same as the IIC+ in terms of circuit and voltage? I know the transformers are different...
 
I didn't know this was too big for this forum, but the day's not over...someone know the answer.
 
The c+ schematic is blurry and hard to read, but there are definite differences in the NFB loop, and the B has a 120pf snubber on one side on the PI plates.



C+
TJynt4.gif



B
9o4KLO.gif
 
Yeah, it is different. I guess the the B has all 6l6, while the C+ has 6l6 mixed with el34.

I don't have a lot of experience with these amps. The only one I've messed with, the guy wanted me to tighten it up and make it less flubby. I don't remember what version it was, nor what I did to it. But he was happy with it afterwards.

I do however remember It had a giant Heat-sink on the back that served absolutely 0 purpose. Literally just riveted to the chassis, no heat generating components coupled to it at all. Oh and it did have 6l6/el34 combination.
 
exo-metal":203x9cl4 said:
The eq is post preamp but it's not pictured.
The graphic EQ is on the preamp schematic and says 'EQ Output' at the out. And then these power amp schematics say 'From EQ' at the input.
 
exo-metal":3riyvtxl said:
The eq is post preamp but it's not pictured.

Here is the full C+ schemo if you want. Has the EQ, and all.

 

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Just curious exo but are you planning to mod a IIB or something? I've been seriously thinking of building a IIC+ HRG recently.
 
CrazyNutz":2863zuaq said:
exo-metal":2863zuaq said:
The eq is post preamp but it's not pictured.

Here is the full C+ schemo if you want. Has the EQ, and all.
Any opinion if this is ideal to slave my Langner preamp for brutal metal tones? I prefer B+ for top end bite and see it is not the same design as the C+ that possibly could be changed to mirror the C+ I'm hoping.
 
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WHERE ARE YOU GUYS!!????
 
I know it's overkill but looking at your rigs...it might work for you. Have you considered/tried something like a Mesa Bass 400? Bass players say it sounds great with 6L6s (6x of them) and it has GEQ but it might be 7-band. The Bass 400+ is 12x 6L6s which just seems like too much.
 
I would have to say it's overkill, not that I'm entirely against that but for now my plan is to use two heads.
 
No... they are different. Big difference in filtering is the additional 2 220uf/300V filter caps (for a total of 4 in the IIC+ & III)... whereas the MKIIB and preceeding amps only have 2 220uf filter caps... which gives them that much looser spongier feel. Plate voltage should be higher in the IIC+ and later amps as well... but not a huge difference.
 
Well I still haven't made my move on the next amp but filtering makes a huge difference. Note taken pal, thx. Hope you're enjoying those wizards.
 
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