Anyone interested in a Mesa Boogie 50 Cal + head ?

[Chevy]

Hi Guys,
I have a Boogie 50 Cal + long head that I've worked on that is now at about 90%; I'd like to sell it to someone at a good price that could possibly complete the repair on it and use it, sell it, whatever. It's in very good shape cosmetically, with only one of the slider knobbies missing.
I'm not doing repairs any more due to health reasons, and am just cleaning up my basement/workshop. The amp originally had an arc from B+ trace over to the LDR power supply trace, which I've isolated and corrected. That was the main problem. I replaced the 4 *potentially* involved LDR's and the diode and cap for the LDR supply as well, just for good measure, in case they had somehow been compromised. Also, I upgraded the power supply with all-new F&T and Kendrick electrolytics.
The remaining problem is heat-related, apparently... I can run the amp in the cool basement for hours at nearly full power on the test bench, and just cannot get it to fail. Aargh. But if I take it to our band's practise space, where they have a wood stove heater and the place is just baking, the amp's output will attenuate drastically after about 20 minutes of playing, then come back, then down again, and so on. Shutting the standby off and on again seems to restore it. So... I'm thinking it might be a transistor in the EQ doing it... can't think of anything else that would do that in the heat.
Anyhow, if anyone's interested, please let me know. Thanks.

[soundguruman]

Those amps are pure evil.

[telecaster]

I like the way the Mesa Studio Caliber (and Dual Caliber) amps sound, and soundguruman has a point - they can make you invent new swear words while working on them. I am interested - how much are you looking to get for it?

[Chevy]

I like the way the Mesa Studio Caliber (and Dual Caliber) amps sound, and soundguruman has a point - they can make you invent new swear words while working on them. I am interested - how much are you looking to get for it?

I really dunno what it's worth... debugged fully it would be in the $500. + range; new output tubes, a few preamp tubes, power supply caps, LDR's... I have over $600 invested. How would $300 sound ?... just want to be sure the buyer knows the exact condition, and can take it the last step to 100%.

[soundguruman]

based on real experience, I would charge $650 parts and labor to rebuild it.
Tubes, all new teflon wire, filter and cathode caps, input jack, new volume control, new plate cathode resistors (1W of course all round), new output sockets, all new LDRs, yes F&Ts for sure, but I use mil grade hi rel 125C caps for the rest...yeah, and the rear panel jacks tend to warp from the heat, so replace all those too. Give the controls, board, chassis and faders a real good cleaning...maybe even change the POS reverb. (besides fixing the burns arcing)
I would say $1000 for a fully working rebuilt one. I guarantee 6 months....but after all that I am fairly confident it would last many several years.
I mean let's face it, the design is a joke. But by extending wires to gain more access, make the board removable easily, you not only fix it, but make it more easily fixable in the future.
Sure I love the sound. But the hours to get it going are enormous. I mean that board is a fugging nightmare.
I just finished one, and my COST on the parts was like, no scrit.
1X Input Jack Mesa 610114
2X Knob Mesa 409108
1X Gain control push pull Mesa 591842
5X EQ knob Mesa 408550
Subtotal Mesa Factory Parts $ 39.47
3X 3.3 uF Tantalum 6.88
1X 2.2 uF Tantalum 5.00
2X 15uF Tantalum 5.50
1X .47 Tantalum 2.00
1X 1uF Tantalum 2.50
3X 220 uF 63V Electrolytic 8.75
2X 220 uF 300V Electrolytic F&T 15.00
3X 47uF 500V Electrolytic F&T 20.00
1 10uF Electrolytic 100V 2.75
1X 68K 1W Metal Film .75
1X 56K 1W Metal Film .75
2X 300K 1/2W Metal Film .50
1X 3300 uF Electrolytic 16V 3.00
5X Light Dependent Resistor 5C4 26.25
1X Light Dependent Resistor 5C1 7.00
8X Teflon hook up wire 8.00
7X 2W Metal Oxide Resistor 5.25
6X ½ W Metal Film Resistor 1.50
2X Ceramic Octal Socket 4.00
8X M3 SS screw, nut, washer sets 4.00
1X 6-32 Screw, nut, washer set .75
2X Tube Retainer Claw 4.00
2X 6L6 Groove Tubes, Match Pair 52.00
2X JJ ECC83 16.00
1X JJ ECC 81 8.00
Shop Supplies
2X Solder Wick, Solder, Cleaners, Deoxit… 9.00

Parts Subtotal 258.60
Sales Tax 20.04
Total Due 278.64 (PARTS AT COST NO LABOR)




if you wondered why the caps cost so much, I was using 125C mil grade. Regular consumer grade caps don't last in that amp.
Oh man, I been playin it thru a couple Marshall 1X12 cabs and it's sweeeeeeeeeeeeeeeeeeeeeeeeeeeeet.




_____________________________

[km6xz]

That is a fair price, too bad it is so many miles away, I would have bought it even though I do not have need for one. They are not as bad as their reputation, just hard to get access to parts of the circuit due to construction choices. The current problem is not heat related, most likely, since it is cleared with toggling standby. Doing that keeps everything at the same temperature so no change would be expected from a heat sensitive component. The send/return jacks could behave that way.
If heat is causing distress for an amp due to the heat of the room, the greater concern would be the guitars. Thermal cycling over extremes would do more long term stress on the wood of the instruments than the amp. Tough on players also.
My shop was not far from Mesa so it seemed that everyone and their brother had one due to the liberal distribution of endorsement gear that was floating around. Every time a group came that used Mesa gear or might be interested in using it, a truck would pull up to the studio rear door and unload a ton of amps. Few of them were ever returned at the end of a project. I even ended up with one and I do not play guitar. Needless to say, my shop saw a lot of them since there were so many floating in the wild. Personally, I never found them to be problematic. Any repairs needed were usually pretty simple and straight forward. Never really had an opinion about their "sound", any functioning amp sounds good or bad based on almost entirely on the player.

[soundguruman]

That is a fair price, too bad it is so many miles away, I would have bought it even though I do not have need for one. They are not as bad as their reputation, just hard to get access to parts of the circuit due to construction choices. The current problem is not heat related, most likely, since it is cleared with toggling standby. Doing that keeps everything at the same temperature so no change would be expected from a heat sensitive component. The send/return jacks could behave that way.
If heat is causing distress for an amp due to the heat of the room, the greater concern would be the guitars. Thermal cycling over extremes would do more long term stress on the wood of the instruments than the amp. Tough on players also.
My shop was not far from Mesa so it seemed that everyone and their brother had one due to the liberal distribution of endorsement gear that was floating around. Every time a group came that used Mesa gear or might be interested in using it, a truck would pull up to the studio rear door and unload a ton of amps. Few of them were ever returned at the end of a project. I even ended up with one and I do not play guitar. Needless to say, my shop saw a lot of them since there were so many floating in the wild. Personally, I never found them to be problematic. Any repairs needed were usually pretty simple and straight forward. Never really had an opinion about their "sound", any functioning amp sounds good or bad based on almost entirely on the player.

"They are not as bad as their reputation...."
No, they are much, much worse. Arrogant, evasive and non helpful, at all times.
Sure the amps sound good, but the customer service and support sucks.

The 50 cal, with so many parts crammed into so small a space, runs hot as a toaster oven.
I prefer to use Hi Rel parts, that's just my personal feeling.
(I did not wimp out like other techs who won't work on them)

And check out the new model, with 54 mechanical relays crammed onto the tiny little medical grade circuit board.
Talk about hell on earth. What in Gods name were they thinking?

I would rather a Fender any day.

[telecaster]

Chevy, I sent you a PM with an offer to buy. If it works out, I will update the forum with whatever I find to be the cause of the remaining volume fluctuation problem.

[soundguruman]

More that likely, it's burning through the fiberglass...

[Chevy]

Wowzers... that's some piece of work... I admire your diligence, TLC, and energy, soundguruman... and thank you very much for your help in the past with this amp's repair. Much appreciated!
And heck yeah, I was very fond of the tone of 50 cal + 's I had heard previously. But for me to get excited about things at this point ain't gonna happen unless my health bounces back... I'll likely do some work on my personal amp and for a few friends, but little else.

[Chevy]

More that likely, it's burning through the fiberglass...

No, that's all been taken care of...

[soundguruman]

Wowzers... that's some piece of work... I admire your diligence, TLC, and energy, soundguruman... and thank you very much for your help in the past with this amp's repair. Much appreciated!
And heck yeah, I was very fond of the tone of 50 cal + 's I had heard previously. But for me to get excited about things at this point ain't gonna happen unless my health bounces back... I'll likely do some work on my personal amp and for a few friends, but little else.

Working on this amp is a "hobby."
Nobody is ever going to pay for all the work it takes to make it work correctly.

That's the whole point. If you are not willing to put a huge effort into it....don't ever expect it to keep working right.

[drewl]

Dang, I've repaired several over the years and never had to replace $300 worth of parts.

[soundguruman]

Dang, I've repaired several over the years and never had to replace $300 worth of parts.

My personal preference was to rebuild it.
For example, the amp, 33 years old, had been played so many hours that the insulation on the wire would crack when it flexed.
But if you have seen it, you would know that the wires are cut so short at the factory that it is impossible to remove the board
without unsoldering pretty much most of them....making it fairly UN-serviceable.

The cycle of heat and cold, hundreds of times, makes the wire insulation stiff. when it flexes, the ends break off the board.
You can re-strip the wire and resolder it, but then, it breaks off again, as you move the board around.
I prefer to change the wires, so that the board can be easily pulled out of the chassis. I am using mil grade wire, with many fine strands.
It can be flexed over and over with no breakage. I spend $1 a foot on the wire, and to me, worth every penny.