Yamaha CS80

Speaking of replacing caps.  For years, I’ve replaced tantalums whenever working on old gear because of their problems like exploding.  There’s one-per-note on the TSB boards.  I just read in eetimes.com <http://eetimes.com/> that there’s another important reason:

http://electronicdesign.com/blog/conflict-minerals-and-tantalum-capacitor-supply-chain <http://electronicdesign.com/blog/conflict-minerals-and-tantalum-capacitor-supply-chain>

I had no idea they were connected with conflict minerals!

And I also didn’t realized what this did to the price when companies switched to non-conflict sources a few years ago:

http://www.infomine.com/investment/metal-prices/tantalite-ore/all/ <http://www.infomine.com/investment/metal-prices/tantalite-ore/all/>

 David


> On Jan 8, 2017, at 9:17 AM, joachim.milson@... [yamahacs80] <yamahacs80@yahoogroups.com> wrote:
> 
> 
> 
> Hi Tom,
> 
> Thanks for pointing these issues.
> 
> You're right concerning the 100uF capacitors. There are 4 decoupling capacitors; two between ground and +15V, and two between ground and -15V. I changed the 33uF one near the IC1 to a 100uF, and I added a new 100uF one near the IC3 (which corresponds roughly to where it really lies on the board).
> 
> As for the 4.7uF capacitors, those on my boards are in compliance with the schematics. Two are polarized and are yet other decoupling capacitors (between -15V and +15V, this time). The other two are non polarized and are located near IC8 and IC9.
> 
> I updated the overall circuit diagram to reflect these. It is available here <http://joachim.milson.free.fr/cs80/overall-circuit-diagram.html>.
> 
> I also put in the photo gallery of the CS80 group a copy of the M-board schematic (p44 of the service manual) where I highlighted the 42 capacitors, and also fixed a couple of missing components and a label inversion (fixed in red). You can find it here <https://groups.yahoo.com/neo/groups/yamahacs80/photos/photostream/lightbox/39825113>.
> 
> Joachim 
> 
>