Getting my C++ back from Mesa today

[DaveP]

Just wondering if anyone would be interested in some gut shots of a factory C++.
It is "out for delivery" and should be here is a couple of hours. I had all the caps replaced, and general
maintenance and cleaning done by Mike B.

 

[Direwolf]

Hi my name is Jeremy and I'm an amp porn addict.

 

[Metaghius]

would love to see gut shots...how much did all that cost to have done?

 

[DaveP]

The caps and maintenance were about 300 plus the 35 it cost to ship the chassis in. The C++ mod was already done
from the factory. I played it and the only difference with the C++ mod appears to be on the clean channel. When the mid pot is
pulled there is a substantial amount of boost. 6-7db increase. It doesn't seem to effect the lead channel. Still playing with it
to find out if there is anything more to it.

 

[Boogiebabies]

Very interested. I have pics of two different versions of the "++". One original from 84 and one more recent
and they are a bit different in the circuit.

 

[DaveP]

Here it is:

 

[jpdennis]

Wow, was everything that clean before (the case, the circuit board, the caps, the components, the standoffs, the - OMG - everything)? :mrgreen: :shock:

Thanks for any reply

Dennis

 

[DaveP]

It wasn't this clean but wasn't that dirty either. All the caps have been replaced, some resisters and anything that looked questionable.
I figured if it's making the trip why not.

 

[jpdennis]

It wasn't this clean but wasn't that dirty either. All the caps have been replaced, some resisters and anything that looked questionable.
I figured if it's making the trip why not.

Thanks. I may have to start a "send 'em to Mesa" fund. I cannot pinpoint the feeling, it is just that having the Mike B man re-work my Mark III seems like a neccessary thing :lol: . And it is even more so since viewing your gut shots. :shock: :shock:

Dennis

 

[av8or3]

Looks like a pretty cool amp Dave, how would it compare to a C+?
It looks like Mesa made the change on the MKIII from the old style thick handmade circuit boards to the newer thinner green mass produced ones we see today.
How does it sound sound?
Jim

 

[chipaudette]

So what do people see here?

I see a big old relay sitting on top of v2. I see a ceramic cap on that relay along with a resistor or two. Cathode bypass cap?

Then I see a couple sets of twisted pair wire going off to the power tubes. One sets goes to the back left power tube socket, where there's something floating over it. What is that? Diodes and cap to make a DC supply from the AC heater supply?

Another pair of wires seems to go to a jack for a footswitch.

So what is the mod? I can't see the values of the caps and resistors on the relay. And, I can't see where they connect in.

I'm dying to know!!!

Cool amp porn... Totally sexy.

Chip

 

[DaveP]

After comparing the III+ to the C+ I have to say the C+ sounds more 3D. Not that the III+ sounds bad just not as organic as the C+.
The III+ mod was definitively worth it. It really improved the tonality of the amp into the C+ zone.
I have had time to play the C++ mode of this one a little more. The mid pushed in it's a regular C+ in both lead and rhythm modes.
With the mid pulled in the rhythm mode gives a huge boost, think of it like the a crunch channel of sorts. Pulled in the lead mode
it adds additional hair on the gain. Not really a huge difference but you can hear it. At volume it's more noticeable.
So overall the C++ is just like a regular C+ with a couple of more tonal options.

 

[Restless Rocks]

The caps and maintenance were about 300 plus the 35 it cost to ship the chassis in. The C++ mod was already done
from the factory. I played it and the only difference with the C++ mod appears to be on the clean channel. When the mid pot is
pulled there is a substantial amount of boost. 6-7db increase. It doesn't seem to effect the lead channel. Still playing with it
to find out if there is anything more to it.

Soooo what you really mean is they were able to make the Mk III R2 circuit before there was a Mk III. Ummmmmhmmmmm!

 

[Boogiebabies]

The caps and maintenance were about 300 plus the 35 it cost to ship the chassis in. The C++ mod was already done
from the factory. I played it and the only difference with the C++ mod appears to be on the clean channel. When the mid pot is
pulled there is a substantial amount of boost. 6-7db increase. It doesn't seem to effect the lead channel. Still playing with it
to find out if there is anything more to it.

Soooo what you really mean is they were able to make the Mk III R2 circuit before there was a Mk III. Ummmmmhmmmmm!

That's pretty much what it is. The current double plus has basically no clean channel so I can 100% confirm there are two types.
I've seen two other amps like yours, but only yours has the relay. Knowing the production dates on the 3300uf supply cap would be interesting.

 

[pokerrules47]

splish, splosh ... spppooooooooggggeee... i need a kleenex and a smoke

 

[av8or3]

Looks like a pretty cool amp Dave, how would it compare to a C+?
It looks like Mesa made the change on the MKIII from the old style thick handmade circuit boards to the newer thinner green mass produced ones we see today.
How does it sound sound?
Jim

Weren't there pictures of a III+ up on this thread? Or am I losing my mind? :?: :shock:
Jim

 

[DaveP]

Weren't there pictures of a III+ up on this thread? Or am I losing my mind? :?: :shock:
Jim

Actually those were in a separate thread but I knew what you meant.

 

[mystidream]

The caps and maintenance were about 300 plus the 35 it cost to ship the chassis in. The C++ mod was already done
from the factory. I played it and the only difference with the C++ mod appears to be on the clean channel. When the mid pot is
pulled there is a substantial amount of boost. 6-7db increase. It doesn't seem to effect the lead channel. Still playing with it
to find out if there is anything more to it.

Soooo what you really mean is they were able to make the Mk III R2 circuit before there was a Mk III. Ummmmmhmmmmm!

That's pretty much what it is. The current double plus has basically no clean channel so I can 100% confirm there are two types.
I've seen two other amps like yours, but only yours has the relay. Knowing the production dates on the 3300uf supply cap would be interesting.

So the ++ mod basically eliminates the clean channel?

 

[DaveP]

So the ++ mod basically eliminates the clean channel?

The clean channel is still intact. With the mid knob pushed in it is a normal C+.
With the mid knob pulled it adds approx. 25db boost in the clean and about 6-7db in the lead.
It acts like the 3rd channel on the Mark III just different in the amount of boost compared to the III.

 

[mystidream]

So the ++ mod basically eliminates the clean channel?

The clean channel is still intact. With the mid knob pushed in it is a normal C+.
With the mid knob pulled it adds approx. 25db boost in the clean and about 6-7db in the lead.
It acts like the 3rd channel on the Mark III just different in the amount of boost compared to the III.

Gotcha. I'll have to hit Mike B. up at some point. I'm thinking about having that mod done to mine. My buddy Joe who's a forum member here has 2 or 3 of the C++'s and they sound phenomenal.