Preference: 100/60 Switch or Simul-Class?

[bpm91]

Guess you find something new everyday. If a Mark has the 100/60 watt switch, it is not Simul-Class and cannot run El34s? Right or wrong, what is the difference? What is your preference?

 

[Elpelotero]

100/60 = no el34's

 

[bpm91]

Can a Mark with Full/Half Power switch have Simul-Class?

 

[Blueracer]

Can a Mark with Full/Half Power switch have Simul-Class?

Yes! I have a med/long head IIC+ that is set up this way.

 

[Elpelotero]

yes, it can have simul-class, BUT it can also have 100/60. The only surefire way to know is by checking the coding on the output transformer

 

[merendina]

Can a Mark with Full/Half Power switch have Simul-Class?

Yes! I have a med/long head IIC+ that is set up this way.

me too

 

[BiZzAr0]

yes, it can have simul-class, BUT it can also have 100/60. The only surefire way to know is by checking the coding on the output transformer

How does one decode it?

 

[MrMarkIII]

yes, it can have simul-class, BUT it can also have 100/60. The only surefire way to know is by checking the coding on the output transformer

Both? I think it's one or the other. I doubt you can have Simul-Class AND 100/60.
Many long heads are mislabeled "Full/Half Power" (front panel) when they are indeed Simul-Class. There may or may not be a Simul-Class sticker on the rear of the chassis.

 

[Boogiebabies]

Not all long chassis had the Simul sticker, especially the C+, so you need to remove the power tubes, grab a flashlight and look at the transformer at the right rear side of the amp. The IIC+ Simul is SC-152019B and the MK III Simul would be SC-152019B for early III's, 562003 for most, and some late Green Stripes have the 562004.

It should look like:

Mesa Eng.

562003

EIA 606-548

 

[bpm91]

yes, it can have simul-class, BUT it can also have 100/60. The only surefire way to know is by checking the coding on the output transformer

Both? I think it's one or the other. I doubt you can have Simul-Class AND 100/60.
Many long heads are mislabeled "Full/Half Power" (front panel) when they are indeed Simul-Class. There may or may not be a Simul-Class sticker on the rear of the chassis.

I've seen a shorthead recently that has the half-power switch on the front and Simulclass sticker on the back with el34s and 6l6s....

Unless this is actually a long head.... I'm just trying to eye it up... speak up if otherwise.

And thanks for all the responses.

 

[Boogiebabies]

That's a long head.

 

[Elpelotero]

yes, it can have simul-class, BUT it can also have 100/60. The only surefire way to know is by checking the coding on the output transformer

Both? I think it's one or the other. I doubt you can have Simul-Class AND 100/60.
Many long heads are mislabeled "Full/Half Power" (front panel) when they are indeed Simul-Class. There may or may not be a Simul-Class sticker on the rear of the chassis.

exactly you got it right...I didn't write that out very clearly.

 

[bpm91]

That's a long head.

I win!

Really off my game this past week.

 

[MrMarkIII]

Eight knobs and four switches on the front panel = long head.
Although, there's certainly nothing wrong with a little head.

 

[bpm91]

Eight knobs and four switches on the front panel = long head.
Although, there's certainly nothing wrong with a little head.

Nope, but it may look silly sitting on my Thiele... unless my measurements are off yet again. Short heads sit perfectly on it, and longheads overhang on each side about an inch, right?

So that red stripe I posted above.... The Full/Half power switch may actually be a Simulclass/Class A switch?

 

[Boogiebabies]

99.98% Simul-Class. 60/100 MK III's seem to be quite rare after the black dots and blue stripes, they do pop up seldomly.

 

[bpm91]

99.98% Simul-Class.

.02% Extraterrestrial Radio Combobulator.

 

[Boogiebabies]

I wonder, now that we are sure it's a Simul Red Stripe, how much more gain you can get by removing C30 off the V3. It's basically the bright reduction mod from the C+.

 

[bpm91]

I wonder, now that we are sure it's a Simul Red Stripe, how much more gain you can get by removing C30 off the V3. It's basically the bright reduction mod from the C+.

Not sure what that entails... However, I am trying to get a hold of this head this weekend.

 

[Boogiebabies]

Sweet. A long chassis flame thrower. If it helps, I bought my mid 90 Green Stripe long chassis for $ 497 with tax at GC about 18 months ago.