Picking right capacitors for old HI-FI repair

Question

Hello everybody,

As a fresh member, I am asking for help to the community as i'm about to repair a broken vintage Stereo my uncle loves. (I want to surprise him!)

I suspected old capacitors leaks and that is exactly what I found. those are soldered on the power PCB.

Il managed to get the reference on it and this is what i got :

- 6800uf 42WV 85°C LQ(M) (2 pieces)

- 3300uf 25V 85°C SU (2 pieces)

- 2200uf 25V 85°C SU (1 piece)

All capacitors are radial, electrolytic and Nichicon branded.

Here are some questions i have :

- I managed to find 6800uf capacitors but not on 42V tension, i only found 40V and 50v references. What tension should i pick? (I guess i'll have to pick 50V, but i whant to be sure)

- I don't understand the "LQ(M) " and "SU" marked on the capacitors, is it something i have to take into account when picking my new capacitors?

He is a screenshot of the parts i think of getting, what do you think? If you think other types and or brands can be better, please tell me.

I also really want to learn new things about passive electronics, so fell free to give any advice!

Thank you!

PS : I hope my english is good enough for you to understand as i'm french...

jw0752 · Accepted Answer

Hi Benjamin, The voltage (Tension) ratings are just tolerances so as long as the replacements are as large or larger than the originals you will be fine. I do not believe the letters that you mention will have any bearing. John

beacon_dave · Answer

There are some clues as to the lettering scheme here: http://www.nichicon.co.jp/english/products/pdf_r/Standardization_p12e.pdf Looks like the LQ series is now obsolete and has been replaced by the LS series. I don't see a SU series there, could it perhaps be a misread of SV which is listed.

jw0752 · Answer

Hi Benjamin,

Here is an information paper from Nichicon that may have more information about the capacitors and the letters you refer to. I scanned it for this information but didn't find it however I may have missed it. The paper is very detailed and well done. You may want to check it out just for some background.

http://www.nichicon.co.jp/english/products/pdf/aluminum.pdf

Also welcome to element 14. Please continue to post about this project as we are interested to see how it turns out.

John

bben · Answer

Hi John,

Thank you for your help, I will check on the pdf file you linked right away to see if I can find information on those letters. I think there will be none knowing the age of the stereo and the capacitors in it but it is worth the shot.

Hopefully the new parts will arrive before next weekend so i can put my soldering skills to the test! I'm thinking of taking some pictures of the repair and making a small post to share the experience to the community.

Thank you again for the help and also for welcoming me .

Benjamin

jw0752 · Answer

Hi Dave, That is the link that I was looking for. I would bet that the SU is actually an SV. The letters are therefore production series codes. John

Picking right capacitors for old HI-FI repair

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