mesa mark iic+ long head - 60\100 or simul

[cc1975]

Posted in another forum as I can't post pics here but need the experts.

Trying to tell if its a simul or 60 100. All tubes in the pics are 6L6s so I know looks akward the two left and two right are the same not inner and outter but they are all 6L6s? Could the simul take all 6L6s or only 2 of them and 2 of the EL34s? I know the transformer says simul?

Any help would be great

Thx

http://www.rig-talk.com/forum/viewtopic.php?f=3&t=150361

 

[Markedman]

I'd say 60/100. Just like mine. Authorized Boogie, can you comment.

 

[snorkel54]

I have a long head markiii that's a simul, it got the same full/half button on the front.

 

[cc1975]

I have a long head markiii that's a simul, it got the same full/half button on the front.

thx. how do you switch between class a/ab? there isn't a switch on this one? one my short head iic++ simul, I have a switch.

 

[MrMarkIII]

Yes, it is a Simul-Class.
Yes, it is a Simul-Class.
Yes, it is a Simul-Class.

The "Half / Full Power" switch on the front panel *IS* the Simul-Class switch.
I know you don't want to believe it, but IT IS TRUE.

EVERY long Simul-Class head I have EVER seen has the same mis-labled switch.

Don't freak out.

And yes, those tubes are in the wrong sockets.
The correct pattern is X-Y-Y-X, an inner pair and an outer pair.
(This is true for just about every amp with four power tubes.)
In a Simul-Class amp, *ONLY* the outer pair may be either 6L6s or EL-34s.
The Simul-Class switch switches between all four power tubes for 75 watts, or "Class A", which is the outer pair only, for 15 watts.
The inner pair is *ALWAYS* 6L6s
Hope this helps.

 

[Markedman]

What if it doesn't have the "simul-class" sticker on the back? The Mesa Mark III manual isn't very clear about this although it does mention that the "half power" switch on the front is the simul-class switch if it is a simul-class. 60/100 is deceptive - the Mark III is 75 watts (green stripe 85) so there really isn't 60 or 100 watts available in the first place. I'm thinking that in non simul-class Mark III's, the 60/100 switch is "tweed" power, but I'm usually wrong. The big question is - how to tell the difference between Simul & 60/100?????? A sticker? Gut check? Two outside tubes go dark or all four just dim? I wish Authorized Boogie would chime in! They do read this forum.

 

[MrMarkIII]

"Simul-Class" and "60 / 100" are two different amps.
The 60 / 100 uses four 6L6s *only*.
Two of the 6L6s get switched out for 60 watts.
So, whenever you hear someone talk about their "Simul-Class amp that switches between 60 and 100 watts", they don't know what they're talking about.
ALL Simul-Class amps (with four power tubes) can use either 6L6s or EL-34s in the outer sockets only. The inner two sockets must always be 6L6s.
The only way to be 100% sure is to check the transformer numbers.
My blue stripe Simul transformer reads:

MESA
561100
EIA 606-821

 

[little-b]

My Red stripe coli was just serviced by Mike and it has the 60/100 switch up front also with the simul sticker on back...sounds fantasticlous!

 

[tony777]

My Red stripe coli was just serviced by Mike and it has the 60/100 switch up front also with the simul sticker on back...sounds fantasticlous!

Lets see a picture of that one, because that is weird.

 

[MrMarkIII]

My Red stripe coli was just serviced by Mike and it has the 60/100 switch up front also with the simul sticker on back...sounds fantasticlous!

Lets see a picture of that one, because that is weird.

Me, too, because it is not a "60/100" switch, it is a "Full/Half Power" switch, innit?

 

[JOEY B.]

My Red stripe coli was just serviced by Mike and it has the 60/100 switch up front also with the simul sticker on back...sounds fantasticlous!

If you have a 100 watt Mark III Coliseum head, somebody farked up bigtime. :roll:

 

[gts]

My Red stripe coli was just serviced by Mike and it has the 60/100 switch up front also with the simul sticker on back...sounds fantasticlous!

If you have a 100 watt Mark III Coliseum head, somebody farked up bigtime. :roll:

:lol: :lol:

 

[Rhoads]

If you have a 100 watt Mark III Coliseum head, somebody farked up bigtime

Good one :lol: :lol: :lol: :lol:

 

[gts]

The big question is - how to tell the difference between Simul & 60/100??????

It's quite simple Markedman: Look at the Output Tranny aka the OT.
If it has Simul-Class on it then it's a Simul-Class amp.
If not then it's a 60/100 watt amp.
End of story!

Here' the pic of the OT on the amp in question.
See where it has Simul-Class on the OT?

 

[little-b]

My Red stripe coli was just serviced by Mike and it has the 60/100 switch up front also with the simul sticker on back...sounds fantasticlous!

Lets see a picture of that one, because that is weird.

heres your pics; .....

 

[tony777]

Just as we thought littleb.
It doesn't say 60/100 it says Full or 1/2 power. I had to picky about the details to avoid any confusion.
I bet it sounds great though.

 

[little-b]

ya..it does sound good..didnt realize there were so many variations of it..So the 60/100 is a totally different beast than the half/full power?...