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WIGGLING 'LITE' IN GUEST MODE

I accidentally a mesa boogie
MUFF WIGGLER Forum Index -> Guitars, Basses, Amps & FX  
Author I accidentally a mesa boogie
sduck
So I've always wanted a mesa boogie. The basic thing, one of the mark series - the original kind. Ever since I was in high school and one of the local bands was the Zobo Funn Band whose lead guitarist, David Torn, who was a friend of mine, had one of the original ones. They've always been out of my price range whenever I've been amp shopping though. Over the years as the models have progressed and improved my lust has remained. For many years the mark IV has been a dream amp for me.

So I've had a search set up on ebay for years, and constantly am getting emails about ones that I can almost afford, and then the price goes out the roof at the end. Even so, I've almost bought one several times in the last 5 years. So, a week and a few days ago someone posted a project mark IV - busted, but possibly repairable. At a price that was impossible to resist. As I've just recently built an amp, perhaps I'm feeling a bit confident about the repair potential. Anyway, I won the auction, and it arrived today.



As you can see, no cab. No reverb tank. No fan. No footswitch. A project. But wait, there's more...

Missing 2 knobs.



Yes, there's only one input jack on this thing. That other hole is where a knob with push/pull switch is supposed to be - the pot shaft is broken off. This presents several possible options for repair - replace the pot, which is a huge undertaking, as the pot above it has to be removed to get access, and there are a LOT of wires involved. Or possible get a substitute pot shaft made and glue it in - less attractive, but maybe easier. But wait - that's the easy problem...



It's missing 3 power caps. I don't know the history of this, but it looks like perhaps one of them exploded, or perhaps someone tried to do some surgery on this who didn't know that you have to discharge these kind of caps a certain way or you'll get electrocuted - but there's some other parts loose, unconnected, or just missing. And this hole in the pcb...



...is a bit alarming, although as far as I can tell none of the traces are disrupted by it.

So anyway, it's going to be an interesting project, and even if I have to end up taking it to a tech to get it working I'll get it going somehow.

Oh, btw, in case you didn't notice from the pics - this thing is loaded with vactrols. Dozens of them. Sometimes stacked up 4 high!
MrBiggs
eek!

I'm impressed with your tenacious spirit. Damn the torpedoes and go for it.
Good. Fucking. Luck
mckenic
Sir, I admire your balls!

Keep us posted?
sduck
I'm not so sure my balls are that tenacious.

My current plan with this is to relist it on ebay, along with another amp, and use the proceeds to get a complete, working version. Turns out there are a lot more missing parts than I originally thought, and getting it working 100% will probably involve pulling the pcb, which is way beyond my skills (well, patience anyway) and will cost a fortune for a tech to do.
Howie_Doodat
Too bad. I don't like m/b one bit, but that mk iv is a great amp.
MrBiggs
Hey this made me think of something. And please take this in the philosophical meandring spirit in which I mean it.

But once you get this all fixed up and working, what exactly will make it at that point a Mesa Boogie? Is these guts, and the basic circuit design, what makes this amp this amp? Can you build your own cabinet, add a speaker and a reverb and tubes and all the other stuff, and still have that thing? Or is a Mesa Boogie amp the sum of all the parts, built by the workers at the company, in the building the company operates?

Of course the same question could be asked about someone rehabbing a motorcycle, taking apart a Fender Strat, etc. How far can it be stripped down and still be the thing it says it is? I don't know much about amps, and I'm not sure what parts of them are the key parts.
sduck
Dunno. It's on ebay right now - it's destined to be someone else's problem/project.

Tough question, of course. Like my guitar - it's a Fender strat, right? Except I built it out of parts I got from warmoth, wilkinson, emg - there's not actually any fender parts in there. It kind of looks like one, and sounds pretty close, but plays quite a bit different.
sduck
Follow up - sold the piece of crap amp-shaped-object. Bid on a few other, fully working ones, and finally won one! It arrived today, works and I'm a very happy camper! Oh, wait - I'm not camping - I live here. Sorry.
mckenic
Sweet!

Audio?
metasonix
I'm glad you didn't ask for my opinion of that MkIV. Having seen the insides of scores of MB amps of all vintages, I can state with reasonable certainty that the chassis in your photos has got a SHIT-TON of problems, and you were smart to sell it. Most likely, the filter caps blew up and caused considerable damage to the power supply, and (if you're really lucky) the output tube bias failed too, and killed the output transformer. Speaking from experience here.

And yes, the MkIV is packed with fistfuls of Vactrols. Randall's early attempt to control everydamnthing via footswitches and/or optional MIDI controller, circa 1988. A maintenance nightmare. A piece of history, from back when he could hire little Vietnamese housewives for $5/hour and train them to stuff PC boards with components piled on top of components. He once bragged to me that he was the "world's largest buyer of Vactrols".

Whoever bought that wreck will strip it for parts, if he knows some electronics. If not, he'll take it to a technician, who will tell him it will cost several hundred dollars to repair. Chances are good it will end up in the trash thereafter......
sduck
Yes, I didn't ask your opinion, but I got it anyway! Such is the power of the internet BWAHAHAHA!

Your opinion coincides with several mesa specific techie ones. I also posted on the mesa boogie board, and got several opinions, almost all of which suggested selling it to someone who could use the parts rather than trying to fix it. I got a breakdown of the costs to put it into a working head state, and if the backside of the pcb wasn't ruined (I.E. didn't need to be pulled to be fixed) it was still going to cost more than just buying a working one, not including the labor time to do the repairs. Pretty silly to work on, in other words.

That backside of the pcb seemed to be the killing point on this - there was no way to tell how much damage really existed back there without pulling it, which is a huge job; and really not much point in doing the other repairs without knowing as it quite likely would be a waste of time.

Strangely enough I had a record number of watchers of that auction, and got quite a few bids at the end. And I got all kinds of weird questions - including some from these same techies who wanted me to do crazy stuff like pulling the psu and testing it before they would bid (yea, right).
JonathanG
Mesa/Boogie products certainly look good, but I have yet to really connect with the way their tones are usually shaped. The last one I had was the F-50, and I found the gain channel quite murky and muddy and sloppy, yet it was hailed as one of Mesa's best products ever at the time of it's release. Dunno, maybe the tubes were blown, but it seems to happen to me every time I pick up one of their amps. Perhaps my ears prefer more British tones..
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