NAD- Mesa Mark IIB Coliseum, Loop Modded insanity!

[Exo-metal]

Dave, that's something to seriously consider.

 

[Racerxrated]

Sounds cool. Here's my issue with the idea of modifying a IIB to get it closer to a IIC+ tone... the reduced filtering of the power section. The IIB (all IIB series amps and earlier) only have 2 220uf/300V filter caps for the power section... not 4 caps... which is why the IIB series amps and earlier sound softer, mushier, saggier, and flabbier. This is why Mesa went with separate power filter printed circuit boards in the Mark IIC and later amps, which all have 4 220uf/300V (2 on top and 2 more on the bottom)... and they definitely sound tighter because of it. Ask Mike B. he will tell you the same. I'm sure the 150W Coli PT/OT set add a certain something, and maybe a little extra oomph... but it's not going to be as tight as a IIC+, III, and definitely softer, saggier than an original IIC+ Coli or III Coli... no way. The feel and response alone. There is only 50% of the power section filtering present. Not even taking in to account the differences in the preamp section. I own multiples of these amps, both original and modified, so I am also very familiar with them.

And as for any long chassis Mark IIC+ sounding better than a short chassis version... applesauce. Extra chunky applesauce. Nuff said there.

After talking with Mike B he did mention the late 2B Coliseums having the same power section as the 2C and C+. Again, this is from Mike as I just chatted with him recently. All the Coliseum transformers are the same, and are also what went into the Strategy 400 series. My amp is VERY tight like a C/C+/III without any boost, and the different power section would account for that. I've owned 2 previous 2B Coliseums and they had the sag/looseness you mention, but not this one. Mike also told me once he upgrades it to a C+ Coli it will resemble an HRG on steroids...tight tight tight. Mostly because of the power section. Jeremy's is K33$ and mine is K34$, clearly having transitional serials as the 2C was right around the corner.

Wiz, I'll have to take a look today/tomorrow as I'm removing the chassis for shipment on Thurs for the conversion. That increased filtering would explain the huge difference between this one and the previous 2 2B Colis I owned.

 

[Racerxrated]

^^^ So, I just pulled the chassis and on the PS-2B board I have 3 can caps, one is 40/350 and the other 2 are 30/500. In front of those are 8 220/285 can caps, 4 on top of 4. Not on a board though.
Seems to be quite different than your previous 2B power section, I'd imagine this is the reason mine is Mark III tight.

 

[Exo-metal]

What about yours Jeremy?

 

[Wizard of Ozz]

^^^ So, I just pulled the chassis and on the PS-2B board I have 3 can caps, one is 40/350 and the other 2 are 30/500. In front of those are 8 220/285 can caps, 4 on top of 4. Not on a board though.
Seems to be quite different than your previous 2B power section, I'd imagine this is the reason mine is Mark III tight.

Yeah... if the power section has been modified with a total of 8 220uf/285V filter caps, that's a different story. The added filtering will make it tighter for sure. Since there is no additional pcb, that's why they are stacked on top of each other. Post a pic if you can while the chassis is out, it would be cool to see what the inside looks like now.

 

[Wizard of Ozz]

On a somewhat related note... I'd like to see what these can do head to head against my Rev C Triple Recto. That would be a steel cage death match.

 

[braintheory]

On a somewhat related note... I'd like to see what these can do head to head against my Rev C Triple Recto. That would be a steel cage death match.

I didn’t know they made rev C’s for triple rectos (just duals I thought). Was yours a different rev before and modded to c specs by Mike B by any chance?

 

[Racerxrated]

Here’s a couple shots...

 

[Wizard of Ozz]

Here’s a couple shots...

Hmmm... those look like the original filter caps... definitely not what Mesa is using now. So that would explain why the power section is like a IIC+ and not like a IIB. Interesting.

 

[Racerxrated]

Here’s a couple shots...

Hmmm... those look like the original filter caps... definitely not what Mesa is using now. So that would explain why the power section is like a IIC+ and not like a IIB. Interesting.

When I talked to Mike about the possibility of putting a 2C board in this, he was surprised at mine not being a 2C based on the serial. He did say that there is always the possibility of transitional amps when you get close to the serials ending for one series and the beginning of the next. This also has the limiter, which was only a 2C/C+ Coli feature if I'm not mistaken.
When this comes back a C+ Coli it will be the one bucket list amp I've always wanted to try, even more than the MCI.

 

[GJgo]

Here are pics factory stock vs. post Mike B work a couple weeks ago. Mine also has 8 caps in the bank, though it didn't start life exactly the same as Racer's.

 

[GJgo]

On a somewhat related note... I'd like to see what these can do head to head against my Rev C Triple Recto. That would be a steel cage death match.

Comparing my Coli to my Rev G triple, it's really apples to oranges. The hugeness sits in a different place. I tend to prefer the Recto's place in audio nature, but the Coli I do think is bigger.
Running these two amps as a stereo rig would be DEVASTATING.

 

[Racerxrated]

^^Definitely more filtering than older 2Bs, like mine. These late 2B Colis have more in common with the C series than they are different, at least in the power section.

 

[GJgo]

Well when we bought these we were hoping to get lucky with some transitional C parts, looks like in some ways we did.

 

[Racerxrated]

Well when we bought these we were hoping to get lucky with some transitional C parts, looks like in some ways we did.

Yes sir!

 

[Exo-metal]

Looks like things were changed after the trip to Mike, and that worked out lol I can't see a triple rec having the upper hand over a IIC+ Coliseum with GEQ. The point of the eq puts it wherever you want in the mix and the rectifiers don't have that.

 

[GJgo]

My Triple has the upper hand in my band mix compared to my DRG++. The GEQ simply can't put the Mark in the same place as the Recto- their basic character is too different. I'll try my ++ slaved into the Coli power section because we all want to know, and I expect it to be bigger, but I don't expect it to cut like the Triple.

IIC+ are the most amazing amps for us overly analytical guitarists to play with ourselves, with, but having been through 3 of them now I don't think they cut a 2 guitar band mix anywhere near as well as a Recto or a Marshall. Of all the Marks I think it's possible that the aggressiveness & rawness of the III might cut the mix the best, and it's the least popular!

I've been through a lot of Boogies. If I could only have one amp, for everything, it would be a Multi-Watt Triple Recto. No question. Fortunately that's not the case & I can get OCD with all y'all.

 

[Exo-metal]

You misunderstood, the GEQ isn't the only component to what I said earlier. The C+ needs it but with the rest makes the magic. If you slave your ++ into the Coliseum better get ready to sell the recto Jeremy.

 

[Racerxrated]

My Triple has the upper hand in my band mix compared to my DRG++. The GEQ simply can't put the Mark in the same place as the Recto- their basic character is too different. I'll try my ++ slaved into the Coli power section because we all want to know, and I expect it to be bigger, but I don't expect it to cut like the Triple.

IIC+ are the most amazing amps for us overly analytical guitarists to play with ourselves, with, but having been through 3 of them now I don't think they cut a 2 guitar band mix anywhere near as well as a Recto or a Marshall. Of all the Marks I think it's possible that the aggressiveness & rawness of the III might cut the mix the best, and it's the least popular!

I've been through a lot of Boogies. If I could only have one amp, for everything, it would be a Multi-Watt Triple Recto. No question. Fortunately that's not the case & I can get OCD with all y'all.

One overlooked option with the dark nature of the Mark series is, don't be afraid to try an upper mid flavored boost pedal to help it cut better. Just drop that gain way back, and throw a Boss SD1, Tube Screamer, Cusack, OD1X etc etc in front and you'd be surprised at how those new upper mids cut like a knife. That's how I had to run my first C+ when I gigged with it. Through V30s it had no problem cutting through with my singers rig.

 

[ZR4400]

I love my 2b Coli with loop mod, EQ, and reverb!!