Help! Is my Mark IIb Simul-class or not?

[erickompositör72]

It has a "Simul-class/Class A" switch on the back

The original owner gave me the original paperwork, but the order states "Hundred Watt Option with 100/60 Watt Switch and Fan"

However, the order doesn't mention anything about the export PT that it has, so I don't know what to think.

When I picked it up from him, it was in "Class A" mode, but he had the speaker plugged into the 4 ohm speaker output, which would be consistent with the usage guidelines of a 100/60, correct?

The amp has four 6L6GC's - STR 430's. I don't want to throw in EL34's unless I verify this is truly simul-class.

Are there any other ways to know for sure? Did they make 100/60 (HRG) amps that had the 100/60 switch mislabeled like a simul-class switch?

BTW, this amp sounds unreal!

 

[s-fresh]

There's always the chance someone screwed around with it, but those "Simul-class/Class A" plates don't exactly grow on trees so the simple answer is that yes, this is a Simul-class IIB. They didn't make individual manuals for each feature combination so I wouldn't worry about that part either. I'm sure the circuit gurus could probably point you to something inside, but that is beyond me.

Cool amp! Looks like they checked every box on the order sheet for that one.

 

[erickompositör72]

Thanks. I'm loving this amp, and got an incredible deal.

It does seem odd, though- the '84 pricing guide that was posted lists the "simul-class" option as a $25 option, on top of the $175 for "Hundred Watt Option with 100/60 Watt Switch and Fan." That $175 option is on the receipt, but simul-class is not.

But then again, there is also no charge for "Export Switch & Transformer (For All World Operation)," which should be an additional $50.

n.b. - the amp was originally purchased in '82.

 

[NineShallDie]

Check the OT. If it’s says simul-class on it, it’s simulclass. Does the number start with 100, it’s 100/60W.

 

[erickompositör72]

Thanks! I had to get my wife's makeup mirror, have her shine a flashlight, and take a picture with my cell phone, but sure enough, I could read "Simul Class" backwards in the mirror!

Very interesting they decided not to charge him for Simul-Class or the export transformer, according to the receipt.

 

[GreyHills]

That's the cleanest tranny I've ever seen (of that era) - doesn't have lacquer oozing out of it.

 

[strattex14]

I believe some of the later Mark IIB's were Simul Class, but I'm not sure when. I have a Mark IIB, with the 60/100 switch. I had it Simul Classed by Mr. Mike Bendinelli at Mesa Boogie. Now my amp is 15W Class A, and 60w Class AB. I have an Electro Voice speaker, and a cab with a Cannaibis Rex in it, as well. I bought it new in 1980. What an amp!