Elpelotero
Well-known member
Has anyone ever A/B these things? Do they sound and function the same? Is one "smoother" or anything like that?
Any diff b/w a modded C+ and factory c+?
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PRS-Ian
Well-known member
I'd be interested as well, as I'm in the process of shipping my mk2C back to the States for the '+' and simu-class upgrade.
Boogiebabies
Well-known member
Some early IIC's used the RP9 board and the 100 transformer.
Supposedly, only the latest IIC's used the RP11A and the 105 transformer.
I have seen late IIC upgrades that still had the 100 transformer, so there is no safe bet unless you have a 100% legit IIC+ with the RP11A and the 105 OT. So in essence, either could be upgraded but may have differences in the circuit board and PT. When upgraded, both with have technically the same preamp circuit.
Supposedly, only the latest IIC's used the RP11A and the 105 transformer.
I have seen late IIC upgrades that still had the 100 transformer, so there is no safe bet unless you have a 100% legit IIC+ with the RP11A and the 105 OT. So in essence, either could be upgraded but may have differences in the circuit board and PT. When upgraded, both with have technically the same preamp circuit.
steelyzappa
Member
I talked with Mike B extensively a few times regarding this subject. He upgraded my main fully loaded (simul/rev/EQ) 2C to a 2C+ and also repaired another 2C+ that I later sold on ebay. THere were actually 2 different looking pre-amp PCB boards that Mesa used durring the 2C and 2C+ production run. Anyway that's a whole different story (without any documented sonic differences) that we can discuss another time. MY main amp...the upgraded 2C to a 2C+ serial # 11,960...I thought sounded smoother and had noticably more gain then the 2C+ (simul/rev/EQ also) which I later bought and sold on ebay (it was in the 12,5XX range I think). My second 2C+ I did have to send to Mike because some of the solder joints were bad and 2 resistors were blown...He fixed it back to spec for around $150 with ship inclu. I AB'd both amps on class A and simul settings in combo form with EVM 12L's in both and exactly the same settings. THe results were similar but not exactly the same (also I had the same tubes in both). THe upgraded one that I still have I think sounded better. I have a bunch of pics and info that I've been waiting to post sometime but just haven't gotten around to doing it.
steelyzappa
Member
Here is part of my accumilated info which I assembled while talking to Mike a few years back. I will later post a link for the complete document with pictures included:
1. In Simul-class models, both 2C’s and 2C+’s utilized the exact same circuit boards with the exception of the preamp board, which came in 2 varieties. Both preamp boards can be found in 2C’s and 2C+’s because their installations overlapped. Even though they were marked RP 10 and 11, schematically and sonically they are identical (the upper pic is the RP10 and the lower pic RP11).
2. The original 2C+’s only differed physically from the 2C’s in the fact that a few resistors/capacitors and some of the wiring changed. Sonically and functionally 2C+’s are superior.
3. As stated in The Unofficial History of the Mesa/Boogie Mark Series- “The Mark IIC with simul-class & EQ, plus or minus the "+", is now considered very collectable, since the Mark IIC models are widely considered to have the best rhythm tone of all Boogies. The price on these seems to be steadily going up.” (http://homepage.mac.com/mesaboogie/MarkSeries.html)
4. And MOST IMPORTANTLY: Recently upgraded 2C+’s sound better and are more reliable than original 2C+’s because Mike now replaces and upgrades components that commonly fail AND he tweaks the reverb and overdrive circuits to sound better than EVER before!
5. Mesa switched power transformers in the middle of the Mark 2C+ production timeline to a larger more powerful unit optimized for the Mesa STR 415 (aka Sylvania 6L6GC) which is no longer made, hard to find, and very expensive if you can find them (they do sound wonderful though!).
The sole advantage to the larger transformer is more wattage; a truer 75 watts. The disadvantages of the lager transformer found on latter 2C+’s are that it makes the amp sound more sterile, less warm, and causes power tubes to sometimes blow and/or wear out faster, with the exception of the STR 415. Simul-class Mark 2C’s and earlier 2C+’s with the smaller transformer (1983 and some 1984 units) are compatible to a wider array of power tubes AND they will last notably longer. Here is a picture of two Mark 2C+’s from 1983 (top) and 1984 (bottom). Both amps are Simul-class and have EQ and Reverb.
Mike said “Latter 2C+’s with the larger transformer are prone to blowing out power tubes. Earlier 2C’s and +’s are slightly less powerful but they sound sweeter and rounder”. Mike’s recommendation for tubes for 2C+’s are as follows (for Simul-class models):
a. red or yellow STR 430 or 425’s for the OUTER sockets (red or yellow because of these sockets are biased lower)
b. green, grey or blue STR 430’s for the INNER sockets.
c. for pre-amp tubes Chinese 12ax7’s are recommended.
d. The original Sylvania 6L6GC’s (STR 415) are the best but are no longer made.
e. Svetlana 6L6’s are NOT recommended. (I can’t remember why)
Which Mark 3 sounds most like the 2C+ stock and can be modified to sound closer to a 2C+ than other Mark 3’s? RED STRIPE!…BUT, Mike said he can modify any Mark 3 to sound more like the 2C+ if that’s what the customer wants!
1. In Simul-class models, both 2C’s and 2C+’s utilized the exact same circuit boards with the exception of the preamp board, which came in 2 varieties. Both preamp boards can be found in 2C’s and 2C+’s because their installations overlapped. Even though they were marked RP 10 and 11, schematically and sonically they are identical (the upper pic is the RP10 and the lower pic RP11).
2. The original 2C+’s only differed physically from the 2C’s in the fact that a few resistors/capacitors and some of the wiring changed. Sonically and functionally 2C+’s are superior.
3. As stated in The Unofficial History of the Mesa/Boogie Mark Series- “The Mark IIC with simul-class & EQ, plus or minus the "+", is now considered very collectable, since the Mark IIC models are widely considered to have the best rhythm tone of all Boogies. The price on these seems to be steadily going up.” (http://homepage.mac.com/mesaboogie/MarkSeries.html)
4. And MOST IMPORTANTLY: Recently upgraded 2C+’s sound better and are more reliable than original 2C+’s because Mike now replaces and upgrades components that commonly fail AND he tweaks the reverb and overdrive circuits to sound better than EVER before!
5. Mesa switched power transformers in the middle of the Mark 2C+ production timeline to a larger more powerful unit optimized for the Mesa STR 415 (aka Sylvania 6L6GC) which is no longer made, hard to find, and very expensive if you can find them (they do sound wonderful though!).
The sole advantage to the larger transformer is more wattage; a truer 75 watts. The disadvantages of the lager transformer found on latter 2C+’s are that it makes the amp sound more sterile, less warm, and causes power tubes to sometimes blow and/or wear out faster, with the exception of the STR 415. Simul-class Mark 2C’s and earlier 2C+’s with the smaller transformer (1983 and some 1984 units) are compatible to a wider array of power tubes AND they will last notably longer. Here is a picture of two Mark 2C+’s from 1983 (top) and 1984 (bottom). Both amps are Simul-class and have EQ and Reverb.
Mike said “Latter 2C+’s with the larger transformer are prone to blowing out power tubes. Earlier 2C’s and +’s are slightly less powerful but they sound sweeter and rounder”. Mike’s recommendation for tubes for 2C+’s are as follows (for Simul-class models):
a. red or yellow STR 430 or 425’s for the OUTER sockets (red or yellow because of these sockets are biased lower)
b. green, grey or blue STR 430’s for the INNER sockets.
c. for pre-amp tubes Chinese 12ax7’s are recommended.
d. The original Sylvania 6L6GC’s (STR 415) are the best but are no longer made.
e. Svetlana 6L6’s are NOT recommended. (I can’t remember why)
Which Mark 3 sounds most like the 2C+ stock and can be modified to sound closer to a 2C+ than other Mark 3’s? RED STRIPE!…BUT, Mike said he can modify any Mark 3 to sound more like the 2C+ if that’s what the customer wants!
Elpelotero
Well-known member
WOW. Great info guys! thanks a lot.
steelyzappa
Member
I never asked Mike about modding a Mark 4 to sound like a 2C+ but from what I remember (and I could be wrong), the Mark 4 was purposly designed to sound more like a 2C+ with alot of added bells and whistles. I've read comparisons from people who owned and compared both amps that feel the Mark 4 really doesn't need any modding and comes the closest to a 2C+ (the drive channel) in terms or focus and the amount of useable gain. I really couldn't say which sounds "more like" a 2C+, a Mk 3 or 4 not to mention the different Mk 3 "stripes", tubes, etc etc.
steelyzappa said:
steelyzappa said:
Hi steelyzappa. Some very interesting facts you posted there. I could really use that link you mentioned right now, or some pics of the RP9, RP10A and RP11A boards.
Much appreciated,
J.
Elpelotero
Well-known member
wow talk about digging up a post from the grave!! I haven't seen steelyzappa around for a while...you might have better luck sending him a PM or an email
Octavarius
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jvk said:
jvk said:thanks, did that
I'm very curious about that document and pics as well. Would you mind sharing this with the rest of us as well if you get it?
sundaypunch
Well-known member
"steelyzappa" hasn't had a post in nearly a year. I wouldn't plan on him replying based on seeing a post here.
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