Mesa Boogie Simul-Class

Are you asking if there's a stand alone power amp block or are you asking about a feature for particular existing Mesa amp models?
 
Are you asking if there's a stand alone power amp block or are you asking about a feature for particular existing Mesa amp models?
I guess for both? 🤷🏻‍♂️

I know Cliff informed that separating the power amp and preamp may compromise intellectual property or the like.

Infringement issues?

Is it modeled in the USA sims that utilize Simul-Class?

Is the 2:90 modeled?

Should this be in a wish list?
 
If it’s not ....Cliff must have a good reason as the Triaxis and the 2:90 was his main rig for some time.

I think it’s significant...but may be a non-issue
 
My 1986 Mesa Boogie MarkIII has the Simul-Class power circuitry.

The outer 2 power tubes can be used with either EL34s or 6L6s. The inner 2 tubes uses strictly 6L6s.

Later on Mesa recommended to stick with the EL34s as they noticed less tube problems and issues.

At 1/2 power it was just the outer tube pair on at 15 watts Class A power.

Simul-Class kicks in at full power with the additional inner pair tubes for over 75 watts of power!

The USA and all the other models sound superb in all the Axes!

The Mark I, MarkIIA and some MarkIIB were prior to Simul-Class.

Just not at all sure if I’m seeing, hearing Simul-Class modeled in the USA amps? Or as an option? .....A simple Class A amp sim same thing?

Do you know if it’s already “baked” into some of the USA sims?
 
I think one of the core questions is "are any of the modelled Mesa amps using the SimulClass approach, or are they using something more like the standard Class AB of the 60/100w models w/o SimulClass.

Then second would be if there's a way to simulate the mixing of the power tubes.

I know for instance that there is no Triode/Pentode functionality in the Axe, but to force Triode you can switch to the 300B power tubes which are triode. A related thought would be whether the IIC+ models are using Triode (like in SimulClass) or Pentode (like in the Class AB 60/100w models).
 
Maybe it’s modeled in or “baked in” somehow? The USA’s have sounded great since my Ultra days!

Maybe a placebo effect ....but I never found any definitive response to these “Simul-Class” inquiries.

I wonder if the class A amps in the Axe are the same concept and use and just without the simul part.

I understand that in Simul-Class the 2 class operate at the same time but with Class A imparting the overall sound and benefits over Class AB.

Class AB providing the needed higher power or wattage.

I take it too that certain Mark II and the Mark IV in the Axe are Simul-Class modeled?

Has anyone AB’d a USA non-Simul-Class with it’s counter part with Simul-Class in the Axe?

I should try doing that myself lol
 
Last edited:
@2112 Leon, I've appreciated your suggestion of using the Tube Pre as a stand in. Was that based on personal experimentation or a recommendation from someone in the know? As I recall, you use the 50:50. I'm wondering if anyone has AB'd against a Simul 2:90 with the standard 6L6's. Cheers, Daniel
 
Back
Top Bottom