Help with Identifying this Mark (Three?) (Picture Heavy)

[jhooper]

Hey all! This is my first time posting, but I've stopped by these forums quite a few times for information regarding Mesas in the past! Thanks for all the information you've already given to me and thanks in advance for any future insight!

Bought my first Mesa at a pawn shop recently and am pumped to finally own one! I'm wondering if you guys can help me identify this guy. From what I gather from threads I've read here, it's probably a Mark iii Coliseum series? I'm just confused however because I thought the K series serial numbers did not go this high (K563.) There is a date code, 2/86,with MB on both the inside and outside of the Chassis. There is also a black dot above the power socket. Please refer to the pictures for more detailed information! I'm leery to take the chassis out of the cabinet unless I have to and am hoping this amp can be identified without looking at the circuitry!


I'd be stoked to learn anything and everything as I can about this amp!



Thanks in advance guys!

Hoop

 

[Agustín Collia]

From what I can gather it is a Mark III (the fact that it has a Rhythm 2 channel and the faceplate give that away) Coliseum (as can be seen by the 6 power tubes and the size of the transformer). What I can't figure out is the stripe, as it doesn't have one where it should be... Anyway, I'm guessing Red Stripe.

 

[themisfit138]

It looks like a Black Dot Coliseum to me. But that date on it would be around the start of the purple stripes. What are the numbers on the Power transformer and rectifier? That would help in identifying. It would not be a red stripe they didn't start until about '87.

 

[jhooper]

Thanks guys! Let me find those numbers!

 

[jhooper]

Alright, output transformer (i think): 562180 EIA606-521

Rectifier (once again, I think) 550185 E1A606-549

Sound right?

 

[themisfit138]

Here are the gut shots from the black dot I use to own. it is different numbers, but that could be because it is a coliseum or it is the transition form the IIC+ parts.

 

[Agustín Collia]

God, I'm so sleepy I didn't even see the black dot above the power cord!
Then yes, it should be a Mark III Black Dot (Stripe) Coliseum!

 

[jhooper]

Nice! Thanks for the information guys!

 

[themisfit138]

So I just checked my blue stripe, it even has different numbers
EIA606-824
EIA606-848
EIA606-832

 

[jhooper]

So I wonder why it has a black dot? It seems like the markings can be kind of cryptic?

 

[themisfit138]

Not all black dots had the IIC+ parts. Yours would be right about the time of the purple stripe. They might have just been in a transition.

 

[jhooper]

Hmmm! So does that mean it's a Mark iii or a mark iiC+? And additionally, how can you tell what parts were being used in the transition?

Can you guys lend any more info on the mark iii coliseum? I'm finding lots of info online, but nothing on black dot colis!

 

[themisfit138]

I don't know a lot about the coliseums. Fretout would be one to ask about that. The black dot is the start of the Mark IIIs. Yours would be at the end of the black dot run and the start of the purple stripe that would be why it has different parts from my black dot which was at the start of the Mark IIIs.
The Mark IIIs go, black dot, purple stripe, red stripe, blue stripe, green stripe.

 

[jhooper]

Understood! Thank you! I appreciate the help! I'd still love to hear more about the coliseums- are they rare? Are they sought after at all? Why does this amp only have two power tubes installed, instead of 6? (It powers up and plays fine.)

 

[jhooper]

Also, is there any way (besides the sticker on the back) to determine if my amp is Simulclass? I see that it has a full/half power switch, but that is not the same function as Simulclass, am I right? I'm doing more research as we speak, but I'd like to know specifically about my amp!

Thanks guys!

 

[igfraso]

It's obviously a Coliseum Mark III.

Regarding the stripe and taking into account the DOB 2/86 and s/n K563:

- I know we are talking about a Coli but the last black Mark III I have seen is an 1/86 with s/n 16715 and the first purple Mk III is a s/n 16657 (probably born on the same month).
- Apparently, Mark III Coliseums started with s/n K500
- The first picture shows a black dot above the power cord but also a shadow of a purple stripe on the upper left-hand side. How does it really look like in person? Is it just a stain or is it a real purple marker stripe? If affirmative, the dot could have been applied at a later date by an owner thinking that a black stripe is more valuable than a purple stripe.

Just my 2 cents. Hope it helps.

 

[igfraso]

Also, is there any way (besides the sticker on the back) to determine if my amp is Simulclass? I see that it has a full/half power switch, but that is not the same function as Simulclass, am I right? I'm doing more research as we speak, but I'd like to know specifically about my amp!

Thanks guys!

There are more technical savvy people here that can give you an answer.

As far as I know, long heads and Colis have the full/have power switch regardless whether they are Simulclass or not.

But you can do a quick visual check on your output transformer and see if it says Simul-Class (like in themisfil138 pictures).

 

[jhooper]

Alrighty! I'll check both when I get home this evening! Thank you!

 

[jhooper]

Two more questions guys!

1. As it sits, what is this guy worth? I KNOW I got a screaming deal just by reading posts about similar amps around here vs. what the pawn shop was asking. Me thinks they didn't do their research very well; To be fair, I didn't know what it was either. I was just pumped it was a Mesa.

2. If I were to take the chassis out and clean it up a little (not the circuit board, tube sockets or guts) is there anything I need to know?

Once again, thank you guys.

 

[jhooper]

- The first picture shows a black dot above the power cord but also a shadow of a purple stripe on the upper left-hand side. How does it really look like in person? Is it just a stain or is it a real purple marker stripe? If affirmative, the dot could have been applied at a later date by an owner thinking that a black stripe is more valuable than a purple stripe.

Nope, this is just a stain. The only markings are a the black dot and the MB you see in the pictures!

Also, this is not a Simulclass amp, as confirmed by looking at the markings on the OT.