Jerry's Gotten-off-butt Yamaha M80 Rebuild Thread

Well, time for a break. My seven year old "apprentice" has suggested the M80 could use a couple of toy wheels she has laying around, so I have to mull that over a bit, lol... :cheers:
 
YAMAHA MOBILE AUDIO

That girl is a genius!
 
Jer, I have a couple pair of those outputs should you ever need them.
 
So yep, the main caps are definitely suspect. Here's the bank after I pulled it...

m80-capbank.jpg


Both 47K's are definitely not good.. check this one out first... note what looks like a black dot in the center...

m80-captop.jpg


I think this is what it eventually becomes... yeah, that's a hole in the cap!

m80-caphole.jpg


Here's all of them after yanked...

m80-capline.jpg


Now, the trick here is... the dimensions I am after are about 70mm high, 62.5mm diameter, and lead spacing of about 25mm. Electrically, 2 are 33K/50V and 2 are 47K/56V. I can probably go shorter, but not taller. I can also probably go thinner, as what I could do there is put some "cushioning" in between the caps and the clamp.

I'm thinking of these guys here

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P13275-ND

Still looking for the 47K's.. ugh...
 
Handmade Electronics, Percy Audio, Apex Jr., AmpsLabs may have some of that weirder shit.
 
Jer, did you put a cap checker on em? I'm real curious to see if they hold any joules at all.
 
laatsch55 said:
And space is tight right??
Click to expand...

Sure is.. the caps are horizontal and provide the support for the PS board that is soldered onto each one, then a clamp holds the caps to the back panel. There's an indention in the main PCB that only goes so far in.. about 100mm horizontal clearance between the back panel and the lip of the PCB. The components on the PS board plus the clearance underneath to the caps take up the rest of the room.

Might have to do some creative thinkin' here... maybe do some cap "banks" with some custom hardware.. hmmm!
 
laatsch55 said:
Jer, did you put a cap checker on em? I'm real curious to see if they hold any joules at all.
Click to expand...

No-gotem cap checker. I could stick my tongue on 'em? :cyclops:

Yeah, I'd be curious too. Probably no reserve current at all.. I know a "good" M80 has to have more balls that this one did(does..).. :study:
 
How bout 3 30 X 50 @15000, in a 3 pak what would the dia be?
 
laatsch55 said:
The 47k @50 is weird, tried 2 24 or 25 stubbies?
Click to expand...

Hmm.. the 47's are actually at 56V ratings, which hurts. I have a couple at 50V I could make work, but I don't know about that...

(ok.. big HMMMM now!) I am looking at the schematic now, and it calls for 45V ratings on the 47K's and 56V ratings on the 33K's. Compare that with what I actually pulled out... the 33's are rated at 50 (lower than "spec"), while the 47's are rated at 56 (higher than "spec").

Hey Dave... next time you have one open and powered up, can you see what's actually going across each? If I can get away with having the 47's at 50 volts, then I think I can make this work.

Or heck.. I'll break out me CAD stuff and do the "bank"... :study:
 
Dude, ......................................................................
 
Just got done going to Lowes, cutting up some scrap building stuff, taking trash to the dump, mowing the yard, and finally cleaning all the birdcrap outta the pool... :cheers:

(yeah, a very rare moment where I do work around the house here... lol)
 
You must log in or register to reply here.
Back
Top