Yamaha C2A preamp: another thread about crackling and popping

Same goes for the C-2a. If its not Rice Crispies. I wouldn't bother with it.
 
Let yer clutch out!

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Them's some small resistors, and all conveniently marked "R" with no further identifier.
 
@clinic-audio
You don't happen to have the parts list for this endeavor do you? This could get confusing real quick removing/measuring/ordering.

I've got the manual but it's not much help.
 
I still need to do this to my C2a as well. I've actually been looking for another one since mine is greyish from fading and if I'm going to be changing out a million little parts I may as well start with a nicer looking example.
 
As you identify each resistor. Compare the printed value on the resistor to the parts list/schematic. If any differences. Go with whats installed.Have fun..
 
Spent most of the day staring blankly at the board print, schematic and actual board.
I started in the dark and over time the light began to flicker. By the end of the day I had it figured out, found what I think was a couple of mistakes on the diagram (two R522s, R520 mislabeled as R521 and another that I can't remember), made a note and pressed on.
Tonight, if the garage isn't too hot, I'll start desoldering indexing and measuring.

Thanks for being there, this would be inconceivable without AK support.
 
Manual obtained from the Yamaha Reference Library (thanks for putting it together AK)

Pics:
R522 #1 (the right one)

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R522 #2 (the wrong? one). Looking at the diagram it should be on the anode of D512 and one post of C514. There is a resistor there, just can't figure out the proper number.

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R521 should be R520?

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@clinic-audio
I'm glad you didn't make a parts list because that was what you'd call a "learning experience". It took hours of poring over the schematic on the computer and a blown up print of the board to marry up the values and make a list of my own.
Now I'll type them up on some kind of order and try to formulate a Mouser order (because I don't have a clue this thread suggested 250MW Vishay RN, any other suggestions welcome)

The deep end, probably not the best place to start.
 
@lowredmoon I hope you don't mind me hijacking your post.

The reason I like to do these is for the next guy with the same problem, I did a thread on my Sansui 881 (love that thing) and if that can help someone in the future I've done a good deed.

Anyway...93 degrees (34c for you @clinic-audio) in my shop today but I pressed on, about half done with the removal. Good thing I don't charge by the hour.
 
All removed (except R561, it's under a flange).

My primary issue:
I assume R551 and R552 are sister resisters(sic) for L/R channel?
R551 is 15 ohms and R552 is 330 ohms.

All of my other 330 ohm sets are accounted for. (507/508, 509/510)

Does the factory screw up?

Everything else is pretty straightforward (so far)
 
Does the physical location of these two ( R551 & R552 ) jive with the parts location sheet in the service manual ?
Does the factory screw up?
Factories are operated by humans...Anything is possible. Maybe repaired before with and incorrect OEM part.
 
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