Mark IIIC+ - modding by myself!!

[Reeko81]

Hi! I've found the right Mark IIC+ schematic. During a short comparation i've found which are the "great" differences between mark IIC+ and mark III (obviously excluding transfo) and i've took the decision to mod the amp by myself. I'm in Italy and it's a bit difficult sending my amp to Bendinelli @ Mesa but i believe i'm on the right path! I've found the right values between the two amps and i'll start modding this week!

Anyone has tried before me to make this work?
Has anyone ever compared like me Mark IIC+ and Mark III schematic?
Maybe we could have a nice talk about this!

P.s.

Due to the poor quality of web avalaible mesa schematic i've bought either mark III either Mark IIC+ schematics from musicparts.com

 

[ytse_jam]

Hi Reeko81, are you italian or just resident in Italy at the moment? Good luck with your mod! It would be great if you could post some pics taken during the operaton!

 

[Reeko81]

Sono italiano e vivo in Italia. In questo momento la mia pcb è completamente smontata aspetto di mettermi all'opera.
Il consiglio che do a chiunque voglia cimentarsi in questa modifica è di confrontare bene i due circuiti (mark IIC+ e mark III) e garantisco che la modifica non è nulla di impossibile da realizzare!

 

[4nkam]

Due to the poor quality of web avalaible mesa schematic i've bought either mark III either Mark IIC+ schematics from musicparts.com

Most of the time those are the same schematics as the free ones online

 

[Restless Rocks]

Yup they will all probably look the same! Another thing to consider is the Mark III drawing is thought to be the original 1985 or black dot version. There were some subtle changes made during the stripe evolution. One thing noone has mentioned yet in the never ending quest for the IIC+ sound is the layout of the circuit board and the relationship certain components have due to their proximity (or lack of) to each other. Randall wrote an article about this which can be seen on the Mesa site. Good luck with that and remember that 500 volts DC will knock your *** up against the wall.

 

[ytse_jam]

One thing noone has mentioned yet in the never ending quest for the IIC+ sound is the layout of the circuit board and the relationship certain components have due to their proximity (or lack of) to each other. Randall wrote an article about this which can be seen on the Mesa site.

If it's the same article I've read, Randall was speaking really in general about that... have you got some more specific info? How can the layout help achieving a better tone? I thought the only issue could have been the magnetic field flux through the area of a part of the circuit (hence an inducted current). Is it a big effect? What's more?

 

[Restless Rocks]

As was mentioned in a post by Boogiebabies; the circuit board in a IIC+ and the MkIII are very different. Even by changing certain components to make the III circuit Identical electrically to the IIC+ There may be more "magical" things taking place in the original IIC+ layout, caused by many factors including the size and shapes of the traces and possibly the silver content of the solder coating. Inductance, Reactance, Capacitance and Resistance can all be affected in very subtle ways that created the Legendary IIC+= sound. It may very well have happened by a combination of genius and good ole fashioned luck.

 

[Boogiebabies]

As was mentioned in a post by Boogiebabies; the circuit board in a IIC+ and the MkIII are very different. Even by changing certain components to make the III circuit Identical electrically to the IIC+ There may be more "magical" things taking place in the original IIC+ layout, caused by many factors including the size and shapes of the traces and possibly the silver content of the solder coating. Inductance, Reactance, Capacitance and Resistance can all be affected in very subtle ways that created the Legendary IIC+= sound. It may very well have happened by a combination of genius and good ole fashioned luck.

 

[Reeko81]

I totally disagree...i'm sorry but i think the real sound was made by different values for resistor and caps also the lack or some different traces in some point of the board and at first most important, those real original sweet transfo.
It's a real bullshit thinking about a different quality board that still changes of affects so much the sound!

These are my only two cents, who cares...maybe i'm wrong!

 

[Dasein]

... It's a real bullshit thinking about a different quality board that still changes of affects so much the sound!

These are my only two cents, who cares...maybe i'm wrong!

You'd be wrong... because they'd be knocking these off by the thousands in China or Korea otherwise.
I think it's bullshit that some dude with a solder gun thinks he's gonna download some schematics and reconstruct genius. It displays an ignorance and arrogance about engineering and a complete lack of respect or reverence for what Mesa accomplished with the IIC+.

Just my opinion......

 

[Shep]

i think this is alittle out of hand...lol...


All that reeko was saying is that he is going to try these mod's out and see how it sounds and whether anyone has tried it before..Nothing wrong with that...

Can i add i wouldn't have learnt so much about how thing's work E.g Amp's, pedals and guitars if i didn't pull them to bit's and "try" stuff out on them..

tell us how you go..


My two cent's...

 

[Dasein]

Hey shep -- read again what he actually wrote...

No one is down on experimentation or learning.... it's the quote I referenced above that betrays his belief here and I called him on it.

simple stuff

 

[Shep]

yeah it's all cool..i think board/solder/wire and placement of part is a big part of amp's..to i think tht mean's i agree with you..?/

 

[Reeko81]

I'm sorry, but you misundestood me....
First of all...i've finished my mod, and it sounds as i expected.
Round lead tone, without those high peaks, more midrangey and bass little less focused than mark III but with a lot of punch.

Second step... for those who doesn't believe on my words, i'll repeat my thought.

I don't believe the magic or the hype of that original IIc+ sound has to be on that board, but on every different value and first of all, the most important are trannies...no way out men...
I've started working on my amp after receiving a mail from Mesa (before i asked them how to mod my mark III head) from no one less than MIKE BENDINELLI...clear??
He suggest me infact to compare mark III schematic and mark IIc+ schematic and find the right values and correct them...now that i've done it i'm happier than before with my mark III, and obviously, i can't expect to play it as a real IIc+ because the REAL difference are trannnies....

Just again my 2 cents...

 

[Shep]

so your amp sounds more how you wanted it to sounds...would you be able to take some pictures of the borad? or even some sound clip's..

 

[Reeko81]

so your amp sounds more how you wanted it to sounds...would you be able to take some pictures of the borad? or even some sound clip's..

Need only to open again my amp...but i think i'll do tomorrow.

It has been a hard work to check well all the traces, cause on mesa schematic you can't read the component code, and first of all...don't forget that the schematic you get for mark III represents the first mark III (black dot), and obviously there are slightly differences between a mark III blue stripes and a mark III black dot.

Unluckly during a move i broke a 6l6 tube, so till now i've only tested the amp with only the el34 on class A...
I've noticed a more round lead sound as i wrote before with my LP standard, clean are not good with a gibson if you use high gain setting, but with the same gain (volume 1) setting with my fender 62 reissue i got a sparkly fenderish sound...and don't forget that i'm only using a class A setting with only EL34 in outer sockets...so i can't wait more to test my modded amp in simulclass mode with also 6l6 tubes...

Don't forget that mark III are a natural evolution of IIC+ sound, with the add of a 3rd channel (that is more like a clean with more gain..but men...listen it with a great LP!!).
If you start comparing schematic like i did you will notice it (they're the same), but this modded amp will never sound like a IIC+...
If you like mesa mark sound---then you'll love more a mark III with this mod, you'll lose those marshally high peaks and you'll add those sweet mesa midrangy tone!

 

[Shep]

i am buying a blue stripe simli,eq,export tranny, reverb long head would it be worth doing this mod?

 

[Reeko81]

Extra worth in my opinion...if you find your lead channel to have too much high spikes..don't waste your time and go modding your amp.

Clean is just good on blue stripes...it's the best clean available on mark III series. But i've found with the mod that becomes more sparkly too.It acquires those glassy fenderish highs.

Deep mode becomes more powerful with the mod, is like a gain boost and add a lot of body to the whole sound, better avoid it with higher volume1 and humbucking guitar if you still want to obtain in class A mode a clean sound.

After all i haven't changed so much parts, component values are pretty similar to IIC+... unluckly this is not the same for those sweet trannies

 

[Shep]

Thanks.. i can't wait to try it out..it will be cool to compare it to my mk iv..and how different each channel sound..

 

[Shep]

Reeko81:

can you send me some pic's of your mkIIIc+ guts.. i want to have a go at doing the mod.. I'm am going to change the lead channel to the c+ spec.. smooth it out and get ridd of those spikes.. it's a nice aggressive amp but those spikes are anoyying me now..