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

[jbeckva]

Can't I just superglue 'em on the back and run some 24 ga wire to the diode bridges?

 

[jbeckva]

About 50 bucks total. Good deal for two

 

[avionic]

Should have picked up 4 of them..

 

[jbeckva]

And a coupla weeks later.... as the "Shpongle Turns", so to speak...

I'm still looking at these two huge frickin caps, thinking.. And I think I'm just gonna "trailer-neck" it (that's a cross between trailer and redneck, btw.. neat term eh?). I'm gonna strap 'em to the back and run heavy gauge wire into the PS circuit board.

So that's leaving the 2 33's for the "big ones". Now.. I'm wondering about those right now. They're the same physical size (about 63 x 63mm or so). And what's important there is that all four (originally) were the support for the PS circuit board i.e. the board is soldered to all four, which in turn are clamped down with a 4 position cap clamp bolted to the back plate.

Soo.. I could go a coupla ways there..

First are these caps that are as close as I can find.. 50mm x 50mm. That would mean I'd need to put some spacers on the caps to still have the clamp hold them. I'm figuring that if I had at least 2 of the 4 caps still in place, that should provide enough support for the PS board.

Or, the other idea.. If I can find some 33K's that are also computer grade BUT I could stand up on end on the inside (won't be any room on the outside after the two big bammer-jammer 48K's get strapped on). That leaves the PS board to worry about, but why not just stand it off from the back? I'd need 4 stand off rods (or whatever they're called) about 65mm long. Then mount the PCB on one end and secure them on the other through the back plate.

Soo picture the back end for a min... (here's an earlier photo here.. )

The caps and clamp go away. Then the PCB is stood off the same distance as if the caps were still there, which should leave enough room to mount the 2 33's vertically. And again just like the 48's outside, the 33's too would have heavy-duty jumpers to the original mounting holes on the PS board.

Hmmmm... might just happen next week, methinkin... I hope to "Shpongle" a few things off walls when it's all done...

 

[laatsch55]

Good Shpongulating Jerry!!!!!!!!

 

[orange]

Are we there yet?

 

[jbeckva]

Yes, we are getting there now. I figured the 33's were ok.. didn't see any leakage on them, and really... without them being the size they are, it would have been pretty tough.

(but why am I now hearing "Edgar Winter" in my head.. buah ha ha ha)

Break time.. maybe later I'll work on getting the top half hooked back up again..

 

[laatsch55]

Got the biggies in there?? Pic loaded slow, see em now.

 

[jbeckva]

Got the biggies in there?? Pic loaded slow, see em now.

Here's another angle...

 

[laatsch55]

My kinda amp mod!!!! Need some cool flames painted on em like fenders.

 

[avionic]

Sweet....Exposed DC rails right next to the phono input plugs..A surprise just waiting to happen.....Bad Idea !

 

[jbeckva]

Sweet....Exposed DC rails right next to the phono input plugs..A surprise just waiting to happen.....Bad Idea !

Yep, I'll be sure to keep my cat out of my room, not drink when I decide to play in the back of it, and use decent INSULATED RCA cables...

(geeze... )

 

[Web Police]

I'd worry about the cats snacking on them for lunch. Better tie a wire from one of the output posts to that grounding terminal on the back of the case to be on the safe side.

 

[jbeckva]

Naah.. door stays closed, and definitely stays closed when the audio equipment is on. Believe me, i fully understand what I am doing and if it was something I'd regret later then I wouldn't be doing it.

 

[avionic]

Didn't mean to upset you...
Just trying to point out safety issues.. I do this stuff everyday. Repair all makes and models.If I find any potential hazards ie. electrocution or fire. I am obligated to correct the issue before returning the unit to its owner.. SAFETY FIRST !

The potential at those caps is 100-160 vdc roughly, with more than enough current to kill.

 

[jbeckva]

Ahh.. but in my case, I am the owner. Nah, I wouldn't do crazy stuff like this to equipment I'm being paid to fix that's not mine. If I didn't have the exact parts like in this situation, that's where it would probably end, or tell them to wait for me to get a parts junk unit. But, since these big bama-jama caps are just begging me to do something with them...

I could also put rubber boots on 'em too, which I probably will if after all this the amp actually comes out of protection, hehe. It's one of those things where I want to see "what happens" first, then clean 'er up before calling the job done. I do appreciate the safety thought tho, and apologize if I got a lil snippy with ya.

ps. I think I figured out where that white/OSC wire went, but I really could use a pic of the bottom side from you (did you get me email?)... just to make absolutely sure I have it "right" before applying power..

 

[avionic]

I didn't get and e-mail..

 

[jbeckva]

The potential at those caps is 100-160 vdc roughly, with more than enough current to kill.

Eh? Oh.. you mean between positive and negative rails, right? Yeah.. wow.. I'll definitely get 'em insulated, one way or another! Thanks for making me take a step back and think, seriously!

 

[jbeckva]

I didn't get and e-mail..

Weird.. ok, check your PM's..

 

[avionic]

M-80 belly shot...