Is my Mark II a C or a C+

[vds5000]

Alrighty, this thread made me pay closer attention to my Mark IIC, and here is what I noticed:
Alrighty, there was another thread I posted this question on, but it was suggested that I start a new thread, so here we go:


1.) The back of mine has your typical 'MB' marking, but it also has the "I" (as discussed in the original post).

2.) The faceplate says 'Pull Deep' over the Master volume.

3.) I tried the 'Loop Test' tonight, and it passed. In other words, when plugging into the 'Effects Return' jack and switching to lead mode, turning the Lead Drive knob had absolutely no effect on the volume or tone.

So, going by the original posting, this could be a C+. Here's where the confusion starts... The serial number is 116XX.

Does anyone have any idea what I'm dealing with here? Any help would be greatly appreciated.

P.S. Thanks Mark!

 

[Boogiebabies]

From the Guide-


In recent months I have witnessed two IIC I’s. These are IIC’s that almost made it to a plus, but had “Pull Deep” faceplates and a stock IIC circuit with the RP11A circuit board. These were very interesting times at Mesa. A customer could have chosen a C or a C+, hence, the “I” looks like the initial swipe of a +, but never got the other horizontal swipe so do your loop tests. I could imagine Mesa having to call on all outstanding IIC orders and asking if they wanted the upgrade. In the C+ transistion around 12,3XX/124XX
a “yes” meant a plus and a “no” could be the “I”.

 

[vds5000]

Yes, the Loop test passed. I assumed that an upgraded version would be marked as such though.

 

[Boogiebabies]

There is a good amount of modification work done in there. With the RP-10 it's not as easy to spot the IIC+ circuit, so I would call Mesa with the serial number. I've seen + upgrades on the RP-10, but none with so much goo, extra wiring and a metalized polyester cap. It may be a +, or close.

 

[vds5000]

Are Mesa the only ones who do the '+' mod? Maybe some hack did it? I'm not the original owner.

 

[Boogiebabies]

Someone else could have done the mods. Mike Bendinelli always marks the "+" and logs the serial number. Without speculating, I would call Mesa to see if the amp ever had a Return Authorization and a $ 3-400 repair bill.