Proper Recap List for Pioneer SX-3500

[DavidBowie]

I've got a pioneer sx-3500 that I'm planning on recapping. This is my first time recapping anything, so I'm worried I chose the wrong capacitors for the job. Included are the values of the capacitors I figured out from the service manual on an Excel sheet, the service manual, and the Digikey link to the capacitors I have chosen.

Digikey Link

I took the capacitor values from the service manual I found online. For the capacitors labelled low leakage, I chose Nichicon UKL or KEMET R82 film capacitors. For the rest, I chose capacitors from Würth Elektronik as the price is pretty great, and I've heard they aren't bad. However, I am worried that I should have more low leakage caps. The physical board has orange-coloured caps to indicate low leakage, but also some peach-coloured ELMA capacitors, which I also believe to be low leakage, but I am not 100% sure.

Furthermore, there is a discrepancy between the board and the schematic. The schematic lists non-low-leakage 220uF 10V capacitors, while the board has the peach ELMA 100uF 16V capacitors. I went with what was on the board and found some Nichicon UKL 100uF 16V capacitors to be safe.

I also think I maybe should replace the large 4700uF 35V capacitors that I believe are for mains filtering from what people say online. I couldn't find them listed in the service manual, but I chose what I believe to be a suitable replacement from Chemi-Con. I've also heard online that these sometimes last longer than usual, so they could be fine, but I have no LCR meter to test them.

Did I make the right choices with these capacitors? Should I have more low-leakage capacitors? Are Würth Elektronik capacitors not good enough for the general capacitors that they list? Thanks!

 

[lumoStoria]

Although I haven't used Würth capacitors yet I suppose there's nothing wrong with them as general-purpose capacitors. Würth is a reputable German company with more than 80.000 employees producing (among other things) electronic components in own facilities in Europe, China, Taiwan, and Mexico. Definitely not a "no-name" brand. Personally, I use Nichicon UPW as general-purpose capacitors since they are often recommended in this forum as good replacements.

There is a bit of a debate on whether to use low-leakage electrolytics or film capacitors to replace the original CEANL or CSSA ones. Usually, I use WIMA MKS2 film capacitors up to 2,2µF and Nichicon UKL for higher values. In general, it might be a good idea to replace capacitors by ones with a higher voltage (like 16V or 25V for original 10V ones) since this helps to increase the durability of the capacitors and higher-voltage capacitors are anyway smaller than their original "predecessors". So, fitting them onto the PCB is usually no problem.

For the main filter caps, you're right that they usually are quite long-lasting. In my Pioneer SX-xxx receivers, I haven't found one that was off regarding the measured capacity. However, I still replace them often since there are also other properties of the caps that might have gone south during their lifetime and are hard to measure. When you still want to replace the main caps, you should both increase the capacity and the voltage by at least one step. Instead of 4.700µF / 35V I would go for 6.800µF / 50V or similar. Remember that, nowadays, the capacity of large caps is often at the lower end of their guaranteed 10% or 20% capacity range. Means, a capacitor with nominal 4.700µF might in reality only have a capacity of ~4.000µF and still be "in spec". This seems to have been different in the 70s where the nominal and real capacity were much closer (at least from my empirical observations).

Hope this information is of any use to you.

Cheers, Sven