50 Caliber Plus - Class A or AB?

[Ric4001]

Is the 50 Caliber Plus a Class A or Class AB amp?

 

[James]

Class A/B I think

 

[LHanson]

Which one? The amp was made in both EL84 and 6L6 tubes. I know for sure the 6L6 version is not class a.

 

[geetarhero]

yea i had the same question. mine has a switch in the back to switch from class A to B so that makes it class A/B right?

 

[Joey707]

As far as I know both versions of the 50 Cal were class A/B. That switch on the back is the ground switch. It switches the polarity of the ac. It does not change the way the power section is operating.

 

[tubelix]

My .50 Caliber Combo with EL84 tubes says Class A on the back (5 x 12AX7 and 4 x EL84). It's not the + version. It has no EQ (optional feature).

It's my belief that the EL84 version amp is not 50 Watt despite the name. True/False?


http://www.mesaboogie.com/manuals/50%20Caliber%20Series.pdf

http://www.harmony-central.com/Guitar/Data/Mesa_Boogie/_50_Caliber-01.html


Edit: "+" marks 6L6 instead of EL84 powertubes.

 

[Anthony50Cal+]

My 50 cal+ is class a/b

 

[fatboy135]

:lol:
great topic, I don´t know if the 50 caliber is A or AB but I could bet 5 on 1 that it is a class AB for one mainly reason.
When you polarizate a tube on class AB you are setting the bias point in the nearest position to the cut zone, with these tube position you ensure that the audio signal will be amplified on all the dinamic range of the tube.
When you polarizate on class A you are setting the bias point just iin the middle of the load curve, so in the best case you could only achieve the half of the max power rating of the tube.
So, a 6l6 could get aprox. 25 watt/per tube, and a el84 11 watts/ per tube on a class AB. In a class A the tubes pushes about 12 watts the 6l6 and 5 watts the el84.
If the caliber 50 watts is a class A you will need 4 6l6 tubes ( that it is possible ) or 10 el84 :lol:
on the other hand 50 watts of pure class A could enrich your electrical company. For that reasons I think that caliber 50 is nearest to class AB than class A.
Anyway I could wrong but my aracnic sense says to me class AB

 

[tommyhawk13]

This has been on my mind as well. I have the "Class A" version, and it's loud as hell. I have read somewhere that Class A can still be used in push/pull applications, and still be considered Class A. Does this have anything to do with it?

Inquring minds want to know.

 

[fatboy135]

in orthodoxism terms a class A is not compatible with a push pull topology, but in guitar amps, that terms are very diffuse, they speak on class A, single ended as the same thing and they are a very good aproach, but... in other fields class A and single ended are not just the same, they are quite similar but they are two modes

 

[rvschulz]

but what is this class a a/b thing and why should it be important ?? inquiring minds want to know.

 

[tubelix]

but what is this class a a/b thing and why should it be important ?? inquiring minds want to know.

Randall Smith's white paper on Class A: http://www.mesaboogie.com/US/Smith/ClassA.htm

 

[mule#1]

I believe the .50+ has 6L6's and the .50 (without the +) has EL84's. I am also pretty sure all .50+'s as AB.

 

[MrMarkIII]

I believe the .50+ has 6L6's and the .50 (without the +) has EL84's. I am also pretty sure all .50+'s as AB.

Correct-o-mundo.
The "+" is often erroneously associated with the optional Graphic EQ.
Again, in the 50 Cal. series, the "+" refers to 6L6s instead of EL-84s.
In the Studio .22 series, the "+" refers to the additional Lead Master control.
The "+" has never had anything to do with whether or not the amp has a Graphic EQ.
Myth dispelled. You're welcome. :lol:

 

[scottcrud]

My .50 Caliber Combo with EL84 tubes says Class A on the back (5 x 12AX7 and 4 x EL84). It's not the + version. It has no EQ (optional feature).

It's my belief that the EL84 version amp is not 50 Watt despite the name. True/False?


http://www.mesaboogie.com/manuals/50%20Caliber%20Series.pdf

http://www.harmony-central.com/Guitar/Data/Mesa_Boogie/_50_Caliber-01.html


Edit: "+" marks 6L6 instead of EL84 powertubes.

Neither versions are 50 watts. The output transformer are 30-35 watt transformers.

 

[auburnshredder]

For not being an actual 50 watts, mine is sure friggin loud

I actually fried a 50 watt attenuator with it...

 

[mule#1]

For not being an actual 50 watts, mine is sure friggin loud

I actually fried a 50 watt attenuator with it...

My 50+ may be the loudest Boogie I own! In the manual they mention it as being one of the loudest amps they put out at that time. It is also very full sounding.

 

[GuitarGoat]

The + model should definitely be A/B...

 

[mxr2000]

Return of the living dead threads. :lol: The 50 caliber plus is a fantastic amp for the price. I like caliber series amps (.22,.22+,.50,.50+) a lot more than the DC series amps or any other of the economy line amps from mesa so far to this date.

 

[mule#1]

+1