Mesa Mark III green stripe head --question about Simul-Class

asookazian · Dec 20, 2006

I just bought a Mark III green stripe head with matching 4x12 half-open back Mesa cab with 150watt Black Shadows. There is a 1/2 power switch on the front near the standby switch. There is a Simul-class sticker on the back of the head. EQ and reverb on this one as well.

There are two 6L6 on the inside and two EL34 on the outside. Is this a simul-class head? I called Mesa and they said that the definitive way of knowing is if it says Simul-class on the transformer(s). I checked that and couldn't see (but I didn't remove the chassis from the head's cab). They also said that there were 3 models of the Mark III; I'm assuming this has nothing to do with the stripe/version.

The owner's manual on the Mesa site does not show a 1/2 power switch on the front but it does show a Class A switch on the back (which mine does not have).

Is this head a Simul-class or not? If so, does it run simul-class in full power and half power modes? This may be the short chassis version, if there was such a thing. It's not as wide as my JCM 800 or Road King.

Anonymous · Dec 21, 2006

If it has the simul-class sticker, then it's most likely simul-class. Since you said if has the half power switch on the front, it's the long chassis version. The long chassis isn't really a long chassis at all, but rather a medium chassis. The short version only has 3 toggle switches on the front. The half power switch on the front is supposobly the same as the simul-class/class A switch, but I'm not sure if this is true or not.

Boogiebabies · Dec 21, 2006

It is a Simul and a long chassis. They did not get longer than 15 inches.
The switch on the front is the Simul / Class A switch.

asookazian · Dec 21, 2006

hey guys, thx for the responses. sounds good to me. this amp is a monster. i have a road king too and this thing with a genz-benz 2x12 scared me in lead channel around 6 & 6 volume. kicks ***! but I wish it had better artificial harmonic (screams!) like the road king.

Boogiebabies · Dec 22, 2006

asookazian said:
hey guys, thx for the responses. sounds good to me. this amp is a monster. i have a road king too and this thing with a genz-benz 2x12 scared me in lead channel around 6 & 6 volume. kicks ***! but I wish it had better artificial harmonic (screams!) like the road king.

Wow,

You have one of my setups. I have the Green Stripe Long Chassis, the RK II and just got a G-Flex yesterday.

It you cannot get the MK III to scream, look at changing the preamp tubes. Mine has old Chinese Mesa ones and it absolutely rips.

Vigo1999 · Dec 26, 2006

asookazian said:
hey guys, thx for the responses. sounds good to me. this amp is a monster. i have a road king too and this thing with a genz-benz 2x12 scared me in lead channel around 6 & 6 volume. kicks ***! but I wish it had better artificial harmonic (screams!) like the road king.

just try to run your treble a lil higher . . . the controls on the III are very sensitive, especially the treble . . . you sure can make this baby scream all over 8)

Elpelotero · Dec 27, 2006

if memory serves me, when MESA told you to look for "simul class" on the transformer, it would mean you should look for the letters "SC" on the output transformer (most likely the smaller of the two further inside the head)