What is simul-class

[mtnb1kr]

In real world terms, what is simul-class? The boogie web site says "Choose Class A for two-tube operation, where clip begins around 15 watts, or Simul-Class for 85 watts of blended magic." Doesthis mean I can get bedroom and small club volumes with the Mark IV? I have a DC-3 now but I think I want to move up to a Mark series, either a III or IV to get heavier rock and metal tones. I just purchased a 2x12 recto slant cab, don't have it yet shipped today, so I considering selling the DC or trading it for a Mark head. Alot of the playing will be at home though and I can't afford both amps.

 

[axwielding1]

I have a Mark III, and in class A it does break up earlier, but it's still VERY loud.. Just not as much headroom. I use class A primarily in R2 for a marshally tone. It works quite well. The techies here can tell you more about the inside stuff. I just know how to apply it.
Mark III or IV will be quite an eye opening experience for ya...
ax. :twisted:

 

[Grandor]

Yeah Class A is still pretty loud.
I use Class A and my gig master volume is just above 2...

 

[dylan7620]

played to 500+ people with 38 class A watts.... it was loud enough :twisted:

 

[vulture2600]

simul class is combining the outputs of two class AB sets of tubes,
4 in all. the first two are connected to the outer most windings of
the output transformer (50 watts). the second set are connected
to windings that are moved in a bit from the first set (40 or so watts).
this is why the 2:90 is 90 watts per channel where as the 2:100 is
100.

 

[Dale B.]

Simul-Class is pretty easy. It's basically combining Class A/B and Class A within the same power section. I don't know if Mesa uses true Class A or if it's a hotter Class A/B push/pull. I'm thinking it a hotter Class A/B.

I know the Lone Star Special isn't true Class A until you run it at it's lowest power rating, which is like 5 or 6 watts. It will run one tube in Single Ended Class A in that power amp mode. A Vox AC/30 isn't a true Class A amp either. It's just a very hot Class A/B push/pull.

I haven't pulled my Mark IV's chassis to see how hot it's running in the outter sockets.

 

[mtnb1kr]

So in it's lowest setting how much power is the MarkIV putting out? Comparable to my 35 watt DC-3?

 

[RussB]

So in it's lowest setting how much power is the MarkIV putting out? Comparable to my 35 watt DC-3?

MKIV's are unique because in addition to running the amp in "Class A", there is a "Tweed" setting which lowers the overall voltage to the power section...this allows you to use 6V6 power tubes. Then there is the Triode/Pentode switch.

Go to the Mesa website and download Randall Smith's latest paper...it explains the various power sections in extreme detail!

 

[t0aj15]

So in it's lowest setting how much power is the MarkIV putting out? Comparable to my 35 watt DC-3?

According to the Mark IV manual it puts out 30, 50, 75, or 85 watts. So to answer your question, 30 watts.

 

[Grandor]

So in it's lowest setting how much power is the MarkIV putting out? Comparable to my 35 watt DC-3?

According to the Mark IV manual it puts out 30, 50, 75, or 85 watts. So to answer your question, 30 watts.

It also says that if you fully saturate the power section then you can get double the wattage. I think this means 170watts is avaliable if you want bleeding ears.