Help I.D. this head please

Hello all. I've been snooping around this forum for a few months and I find it to be extremely helpful and resourceful. I was wondering if I could borrow your knowledge and hope you guys could help me identify this head. I bought this from a really cool vintage music shop in Minneapolis. The place is small and really cluttered. You really have to dig around and move heads and cabs to find whats behind or under other amps. Its a really unique place and I'm sure if you asked the owner nicely he would also sell you a Gremlin. So I know the amp is a Coliseum but I'm wondering if its a iib or a iic. The only info I could find on the early marks was from Wikipedia and I really don't consider that a reliable source. What I did read was some coliseums used older surplus parts so they can be difficult to identify. I pulled the chassis out and I couldn't find any kind of date on it except for one on the fan that read it was made in 1982. It also has the letters KG written in sharpie all over the chassis. It also has Prince 2 written on the chassis. Considering we are both from Minneapolis it is certainly possible that this was one of two made for him. Here are the pics and I look forward to hearing everyones thoughts. Cheers, Ross.






The serial number is K311. I forgot to mention that this thing sounds amazing. I was looking for that old Metallica sound and it delivers all day long. The distortion is really tight and fluid. I love my mark iv and my DC-5 but this amp is what I've been looking for since I started playing Mesa's. I couldn't be happier with the tones.

It's definitely a IIC. Do the loop test to make sure if it's a + or not.
This is a rare bird for sure.

KG is a code for Coliseum & Graphic EQ.
As far as I can see the motherboard is SP11, is that right?, I thought they came in the c+ production, but I might be wrong, it's the non-reverb motherboard anyway. At the moment there is a IIB coli with higher serial number on the bay, so I would call Mesa to know if they have any info about the amp.
Anyway if it delivers about the same amount of gain as your MKIV, it's most likely a C+.

Of all the amps that I've seen posted here on the boogie board lately, this should be the one sent into Mike B. at Mesa to have a good going over. Do yourself a favor and go back to that music store and look for an amp marked Dumble. Mesa could also tell you if it was made for Prince.

Dude... You SCORED!

Thanks for the info Tony. I really didn't notice the number on the motherboard but I will post some pics of it. Inside the chassis written in marker it has the initials of MB. Is this the same Mike B I have read about around here ? I'm going to contact Mesa about having someone look it over once I pick up a live in head case for it. I was also wondering about the two quarter inch input jacks on the bottom of the chassis next to the preamp tubes. Is this for the reverb ? I'm wondering if maybe it did at one time have reverb and someone removed the tank. I haven't done the loop test yet but the gain on this head is just as heavy as my mark iv. Interesting enough, I run my mark iv pretty hot to get the saturation and I tame the volume with my Rivera Rockcrusher. This mark iic gets that same distortion at lower volumes without needing the power brake at all. Thanks again for info, Ross.
http://i124.photobucket.com/albums/p20/drinkingdeath01/IMG_1817_zpsyteyuew1.jpg
http://i124.photobucket.com/albums/p20/drinkingdeath01/IMG_1818_zpsuqhnlxkh.jpg

Markedman, yeah no Dumble to be seen but if one did pop up it would definitely be in his shop. I plan on sending it back to mesa for a look over once I get a head case for it. Thank you for the info, cheers, Ross.

Did you do the loop test:

The Loop Test –

1) Plug your guitar into the Effects Return jack
2) Switch to lead mode
3) Turn the Lead Drive and Gain controls with a note ringing.
4) If they have NO effect on the volume and sound you have a+.

The jacks on the bottom are EQ footswitch, and a preamp/poweramp split. Go to Mesa website and download the manual and you'll find out which is which, I can't quite remember. I never use them. And; your amp has never had reverb.

tony777 said:

Did you do the loop test:

The Loop Test –

1) Plug your guitar into the Effects Return jack
2) Switch to lead mode
3) Turn the Lead Drive and Gain controls with a note ringing.
4) If they have NO effect on the volume and sound you have a+.

The jacks on the bottom are EQ footswitch, and a preamp/poweramp split. Go to Mesa website and download the manual and you'll find out which is which, I can't quite remember. I never use them. And; your amp has never had reverb.

Click to expand...

It is a C and if it is not a + mike can make it one.. Weird on the serial, I have a IIB Coli K33X

Thanks guys for your replies and help but I'm going to throw a wrench into the whole mix. So I did the loop test and it appears that it is a C+. The problem is that I also called Mesa and after talking with Jerry in service I'm left with more questions then answers. He ran the serial number and it comes back as a iib. When I mentioned that we all were leaning toward a C he said no, that my chassis was made in 79 and it can't possibly be a C. I then mentioned that it appears to have the original fan in it and the fan is dated 82. He then said its possible the amp was made in 82 or later. I then mentioned the loop test and he didn't seem to know what that was. Really quick let me mention that Jerry was a very nice guy and I can tell he was trying to help me as best he could. I don't want to give the impression that I had a negative experience with him because I certainly didn't. So with that being said, I'm still trying to figure out what model this thing is. Oh I did ask about the chassis having Prince's name on it and he said Mesa wouldn't have any kind of record of who it was made for. I do plan on sending it in to Mesa for service within the next couple of weeks so maybe once its there they can figure it out. Does anyone here happen to have a schematic or pics of the circuit board listed somewhere so I can do a side by side ? That would help. On a side note, I play metal and this thing has more gain then my Kerry King JCM 800 and my Ampeg VH140C. I play it with the gain boost off and its sounds amazing. If this is a iib then I can't imagine what a real iic+ sounds like. Thanks again for all your help. Cheers, Ross.

I"d lean to a C because the preamp board has a ton of LDR's but the IiB and IIA had none... and they had the relay which your pic doesn't seem to have.

Deeper mystery for sure...

Serial number would be Mark IIB - but Board Rev will tell all. Thanks!

OK, I just got the details from Mike B.

Your amp is indeed one that was converted to a C+ for Prince on the Purple Rain tour. It was originally a IIB (per the serial number) - but Prince liked the punch of the C+. Great score!!

:mrgreen:

Terriffic help from Authorised Boogie !!

I'm wondering as it's marked "Prince 2" if this baby has a brother or sister ?

Now that would be quite a find...

And bloody hell, imagine the onstage punch if it/they were used in anger.....

McBarry said:

Terriffic help from Authorised Boogie !!

I'm wondering as it's marked "Prince 2" if this baby has a brother or sister ?

Now that would be quite a find...

And bloody hell, imagine the onstage punch if it/they were used in anger.....

Click to expand...

Yes, Prince had a couple of them modded to C+ specs. After we spoke on the phone I got a chance to discuss things with Mike B...he had some great stories about the amps. Apparently they were rehearsing for the Purple Rain tour and guitar techs were getting axed left and right because they couldn't work out "the tone" - Prince was at the point he was skipping through the guitar solos due to his unhappiness. Mike B was flown out to figure out the C+ modded amps, and saw that they had 2 sets of cabinets - one of which was wired in series and the other wired in parallel. There was an impedance issue causing bad tone (!)...once he sorted it out Prince was happy, the tour went off beautifully, and the rest is history!

Authorized Boogie said:

McBarry said:

Terriffic help from Authorised Boogie !!

I'm wondering as it's marked "Prince 2" if this baby has a brother or sister ?

Now that would be quite a find...

And bloody hell, imagine the onstage punch if it/they were used in anger.....

Click to expand...

Yes, Prince had a couple of them modded to C+ specs. After we spoke on the phone I got a chance to discuss things with Mike B...he had some great stories about the amps. Apparently they were rehearsing for the Purple Rain tour and guitar techs were getting axed left and right because they couldn't work out "the tone" - Prince was at the point he was skipping through the guitar solos due to his unhappiness. Mike B was flown out to figure out the C+ modded amps, and saw that they had 2 sets of cabinets - one of which was wired in series and the other wired in parallel. There was an impedance issue causing bad tone (!)...once he sorted it out Prince was happy, the tour went off beautifully, and the rest is history!

Click to expand...

....and all was well again

Neat story!

Hello all. First off let me apologize for my absence, I was having all kinds of trouble logging in this last weekend. I was reading the news and comments and banging my head against the screen because I couldn't reply. Thanks to Ned I'm back in business. Honestly I'm not sure what to say, I'm just floored on what I managed to score in a little cluttered music store that's right down the road from my house. The story behind this amp only ads to the greatness that is Mesa Boogie. The sound, innovation and customer support is untouchable. The fact that Mesa takes the time to do some research on behalf of some random guy on the internet just blows me away. Authorized Boogie, I can't thank you enough.
I also want to thank everyone who commented on this thread. Your input and expertise is top notch.
As a weekend gearhead warrior all I can say is keep hitting up the obscure. I've spent numerous hours in silly music stores and seedy pawn shops only to be disappointed, but every once in awhile, you hit pay dirt. I've found some great gear for great prices but nothing like this. I feel like I've found a Picasso at a garage sale.

That is one AWESOME find! Congratulations!

drinkingdeath01 said:

Hello all. I've been snooping around this forum for a few months and I find it to be extremely helpful and resourceful. I was wondering if I could borrow your knowledge and hope you guys could help me identify this head. I bought this from a really cool vintage music shop in Minneapolis. The place is small and really cluttered. You really have to dig around and move heads and cabs to find whats behind or under other amps. Its a really unique place and I'm sure if you asked the owner nicely he would also sell you a Gremlin. So I know the amp is a Coliseum but I'm wondering if its a iib or a iic. The only info I could find on the early marks was from Wikipedia and I really don't consider that a reliable source. What I did read was some coliseums used older surplus parts so they can be difficult to identify. I pulled the chassis out and I couldn't find any kind of date on it except for one on the fan that read it was made in 1982. It also has the letters KG written in sharpie all over the chassis. It also has Prince 2 written on the chassis. Considering we are both from Minneapolis it is certainly possible that this was one of two made for him. Here are the pics and I look forward to hearing everyones thoughts. Cheers, Ross.






The serial number is K311. I forgot to mention that this thing sounds amazing. I was looking for that old Metallica sound and it delivers all day long. The distortion is really tight and fluid. I love my mark iv and my DC-5 but this amp is what I've been looking for since I started playing Mesa's. I couldn't be happier with the tones.

Click to expand...

Very cool find and a great story. Hold on to that one forever.

A Prince Coli....wow
RIP