''Caliber history''

[bartchamdoh]

Here for your edification is a short history of the studio caliber series amps....most of the information here is sourced from the vintage guitar price guide(2008) and the mesa product guides for 1984/1986/1995 and 2004 respectively.The caliber series was launched in November 1985 with the release of the studio caliber.22.As the name suggests it was Boogies first low wattage practice amp and the low price ensured it was a huge hit as now guitarists could afford a boogie without remorgaging their house lol.The next step was to extend this budget range with higher output models the .38 special(four el84 tubes,38 watts) and the.50 caliber(two 6l6 tubes,50 watts) or so advertised the 1986 product guide!!! in practice the four el84 model came out in January 1987 and ran until the end of 1988 and was repackaged as the .50 caliber and was revamped with 6l6 tubes and a pull channel switch from 1992 til 1993 and called the .50+ cal.The original studio .22 was revamped as the studio .22+(in December 1988) with an added lead master switch and plastic toggle switches for on/off,stand by and eq which were previously the metal mark series type(this was the same for the revamped .50+ cal).In 1993 this range was replaced by mesa,s second budget range the Dual Caliber amps.

 

[GD_NC]

Thanks great info. Most people don't realize the .50 cal was an EL-84 amp. Adding "+" does not seem like a great way to indicate that you have completely changed the power amp ! Funny, they didn't stick with the original .22/.38/.55 naming scheme but returned to it with the DC-2/3/5.

I've never heard of or seen a .38 special. Anybody out there have one of these? Did they ever make it to production? Pics? You have to wonder if a band with a similar name had something to do with the name going away.

 

[Fxrs]

Thanks great info. Most people don't realize the .50 cal was an EL-84 amp. Adding "+" does not seem like a great way to indicate that you have completely changed the power amp ! Funny, they didn't stick with the original .22/.38/.55 naming scheme but returned to it with the DC-2/3/5.

I've never heard of or seen a .38 special. Anybody out there have one of these? Did they ever make it to production? Pics? You have to wonder if a band with a similar name had something to do with the name going away.

I have the 1995 (I think) catalog from when I bought my DC-5, and in the DC section there's a blonde amp called the Palomino whose description was interesting, but I believe I read somewhere on this board that it was never released. Maybe the same w/.38 Special?

 

[bartchamdoh]

That's a cool observation i had never thought about the Palamino amp and i,ve the 1995 product guide since it came out lol.

 

[&drew]

Thanks bartchamdoh for the info.

I bought my .22 in summer 1988 for £650 just a few months before the .22+ was released - now I'm trying to turn it into a '+' with the Master Lead and Lead Gain mods. If only I'd waited...

The .22 was R. Smith's first 'hit single' according to the blurb I have. His signature is on the inside of my amp's chassis.

I've just cleaned all the contacts and pots for their first time in 22 years and it sounds better than ever. What a great amp. Well worth a "TUNE-UP". Tried various pre-amp valves to get best tone/least hiss with good results -
12ax7's: RFT give great early overdrive, Mullard lovely openness, 7025 lower noise but less overdrive,
but MESA EL84's are safest bet regarding bias IMHO and work perfectly.

If anyone picks up a tatty one for peanuts and restores/renovates it they will have a Boogie capable of many classic tones.

The only fault I've had has been to replace resistor R131 with a 1K, 2W version. They usually burn out as the original design was under-rated. But it's only for the foot switch so no signal/tone worries there.

 

[Old BF Shred]

I have a catalog from the late 80's that mentions the 38 special in the product list on the last page, but is not actually shown anywhere in the catalog itself. I always found that odd.

Perhaps now I know why.... :wink:

 

[jpdennis]

12ax7's: RFT give great early overdrive, Mullard lovely openness, 7025 lower noise but less overdrive,
but MESA EL84's are safest bet regarding bias IMHO and work perfectly ... The only fault I've had has been to replace resistor R131 with a 1K, 2W version. They usually burn out as the original design was under-rated ...

Thanks for the information about the tubes and about the resistor. I am in the process of a tube quest as well as checking worn electrical components on two of my amps. Good information to hold onto.

Dennis

 

[&drew]

A pleasure Dennis.

I've also read that over time some of the capacitors can wear out too, which I may look into. Maybe more important on an amp that has toured for years.

For any old amp (even un-used & in storage for years) I would suggest cleaning the pots with Faderlube and all the contacts with Deoxit D5. There may be other brands of de-oxidant/lube available. Not cheap but worth it.

I know I'm often saying about cleaning the pots & contacts - but I've just discovered what an amazing difference it can make to an old amp.

My 1988 Studio .22 now sounds as good as when I bought it 22 years ago, coincidently when I was 22 years old.

Sounds even better actually - as I didn't have a real LesPaul back then. Straight in, no FX, some fine tuning of controls and it sings, growls and crunches. Awesome.
Even the Rhythm mode sounds good now, though not as good as my Nomad Ch1 cleans, which I understand are more like DC5 cleans.

[By-the-way, a complete set of Mesa tubes should work just fine in any Mesa amp IMHO but tone neurotics like myself can find nuances in sound by using different ones. All pre-amps are 'Class A' and don't need have their bias set, so any compatible tube can be used - but they will all sound slightly different (at least).

For Mesa amps a good tube vendor should be able to sell you power valves that are in the MESA bias range. I picked up 4 Hama EL84s that were selected to suite the fixed bias of my Mesa Nomad. Otherwise I would use Mesa power tubes in Mesa amps. Any thoughts anyone?]

 

[Sixstringpsycho]

Great post of the caliber history.

 

[igfraso]

If I recall this correctly, serial number range for Studios .22+ goes from FP11,500 (December 88) up to FP28,560 (August 93).

 

[igfraso]

Also, the 2 Caliber products that never saw the light (at least, as intended) were:

- the Caliber 2x12 vertical cabinet (with 2 x V30)
- the Dual Caliber Palomino (with 4 x EL84?)

Maybe, the Palomino morphed into the Maverick or the Lone Star Special and the Caliber cab was absorbed by the recto cabs.

 

[eschoendorff]

Any more details on the Caliber history (lineage) would be appreciated. Great stuff!!

 

[mxr2000]

Hello anybody here knows a place to get the schematic for the mesa boogie caliber .50 plus clean channel extra master mod, this amp for me is the best boogie for the price the only thing that could make it perfect is to add an additional master for the mismatch in volume for the lead and clean channels

 

[MesaBodgie]

bartchamdoh, good history of the Caliber.
I think the dates you supplied for the 50 + are a bit wrong.
I have a Caliber 50 + and the signatures on the chassis, in felt pen, are dated mid 1990.
Cheers.

 

[O==00==O]

So, this "studio caliber" (no .22 silk-screenage) is from possibly '84? Pfft. Almost as old as me... With the tone to match.

 

[Fxrs]

Also, the 2 Caliber products that never saw the light (at least, as intended) were:

- the Caliber 2x12 vertical cabinet (with 2 x V30)
- the Dual Caliber Palomino (with 4 x EL84?)

Maybe, the Palomino morphed into the Maverick or the Lone Star Special and the Caliber cab was absorbed by the recto cabs.

The Palomino and the Maverick are both in my catalog.

 

[igfraso]

The Palomino never saw the light.
Regarding the Maverick, there were the prototypes (dark panel) and the normal series (brown panel).

 

[mxr2000]

Hello anybody here knows a place to get the schematic for the mesa boogie caliber .50 plus clean channel extra master mod, this amp for me is the best boogie for the price the only thing that could make it perfect is to add an additional master for the mismatch in volume for the lead and clean channels

bump

 

[&drew]

Hello anybody here knows a place to get the schematic for the mesa boogie caliber .50 plus clean channel extra master mod, this amp for me is the best boogie for the price the only thing that could make it perfect is to add an additional master for the mismatch in volume for the lead and clean channels

Hi
I would suggest a search of this Forum or google for the Caliber .22 master volume mod.

As far as I know the mod is the same for Caliber .22 as .50

Good hunting

 

[bulby]

bartchamdoh, good history of the Caliber.
I think the dates you supplied for the 50 + are a bit wrong.
I have a Caliber 50 + and the signatures on the chassis, in felt pen, are dated mid 1990.
Cheers.

I also have a .50 Caliber+ and the signature says 89/4.

P.S. New to the board, I got this amp a week ago and it is my first Mesa