SX-750 recap - part substitution help please

I'm preparing to order parts to recap my son's SX-750 and wanted to say thanks to Mark, Larry, Watthour, Zeb and so many others that have provided such a trove of great information. It can take some time to wade through, but it's worthwhile for sure.

I tried a couple of the BOMs previously published/vetted by Mark the Fixer, to find the one w/least out-of-stocks and have a pretty good list going, but there are just a couple of items I need to reconcile.

Mouser is out of the 647-UKL1H010KDDANA 1uf, 50V cap that appears in 6 places. The recommended subs from their tool are all 'on order', too. Would Mouser 647-UPX1V010MPD work instead or would 667-ECQ-V1H105JL3 film cap be better? At 1uf, it's at the top end of the small value threshold where Mark and others suggest replacing electrolytic w/film.

I've got the 'BP' cap in location C86 of the AWE-073 tuner/control board. I seem to recall a film cap was recommended in it's place, but I wondered if 647-UEP1H4R7MDD, a 105 degree, bipolar electrolytic from Nichicon would be preferable?

A final question that the BOM tool Help feature didn't help with. Can you tell me how to remove/add to a BOM? Must it be exported, then edited, then re-imported?

Thanks for the help,
Ron

Go with the ECQs for 1/50 UKLs.

I don't know off-hand which board the AWE-073 is. If that particular cap is in the audio path, a better one to use would be the UES version. I doubt you'll find a small enough film cap at 4.7uF/50V. If that cap is next to a high heat source, what you've chosen is fine, but you could also use the Panasonic SU series or the Nichicon VP series which, though rated to 85C vs 105C, are rated to 2000hrs vs 1000hrs. Originals were only rated to 85C I'd guess.

Digikey has those KL parts in stock.

http://www.digikey.com/product-detail/en/UKL1H010MDD1TD/493-10497-3-ND/4317986

I believe the Elna Silmic IIs are the next best thing for leakage if you want to stick with mouser.

http://www.mouser.com/ProductDetail...GAEpiMZZMtZ1n0r9vR22Vaq1AHMe%2bCMGxv1JEyDvCA=


EDIT: WIMA film caps are also very good if you have the space to fit them.

http://www.mouser.com/ProductDetail...=sGAEpiMZZMv1cc3ydrPrFwgzP98AO9idE1x3ZUTCoHM=

No affiliation

SoundOfSound said:

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I believe the Elna Silmic IIs are the next best thing for leakage if you want to stick with mouser.

Click to expand...

I wish folks would quit saying that Silmic IIs are the next best thing to sliced bread, able to do any job, anywhere. They are great audio caps, but do your research.

if you look at the data sheets, film caps don't even list leakage current as a consideration it's so low to non-existent. that's why they are listed as DC blocking caps sometimes. if you don't go with film, tantalum will have the next lowest leakage factor (after UKL) ...it's one of the design features. There are failure mode problems with tantalum caps (though I've never had one fail) so I replace with film or UKL.

leakage factor:

UKL is 0.002 CV (0.2 uA) after 1-2 minutes depending on case size
Silmic II - 0.01 (3uA) after 5 minutes
Nichicon KZ, FG, KW, VZ- 0.01 (3uA) after 2 minutes
Panasonic FM, FC, FR, FK... - 0.01 (3uA) after 2 minutes
tantalum (typical) 0.5uA (in values typically seen for LL caps in vintage gear)

So, if you need a LOW LEAKAGE capacitor, and need to use electrolytic, SILMIC II is NOT your best option! Let the data speak for itself.

647-UKL1H010KDDANA 1uf, 50V to UKL1H010MDDANATD

is 667-ECQ-V1H105JL3 film cap be better? yes, non-polarized perhaps better "sound" and it has longevity. as long as it FITS the available space!!

c86 in the tuner is a ceanl 4.7uf 16v cap and it IS polarized!!!!
CEANL means use a UKL cap!!! like 647-UKL1E4R7MDDANA which has a stock of 5000+ on hand.
I don't know what this "bp" bupkis is about.... and I don't have time to try to dig out the error.

BOM can be put in cart and changes made to cart.
or if you save it as a project.

Thank you good people for the helpful responses! Sorry it took so long to acknowledge them.

Mark, I may well have it wrong, but it sure looks like c86 is a 4.7uf/25V electrolytic and instead of minus signs on the case stripe, it says 'BP' repeatedly along the stripe. It's the orange cap right next to pin 43 in the photo. I could have sworn I've seen you talk about this cap in other posts.

Thanks for the tip on adding to the cart or a project to edit. I exported the BOM and was able to make the substitutions, then upload a new BOM. Not the most efficient method, but it worked! I need to explore the Project option. =)

Thanks again!

c86 in the tuner is a ceanl 4.7uf 16v cap and it IS polarized!!!!

Click to expand...

C86 in the sm is a ceanl 4r7m16np
which i translates to be a low noise electrolytic non-polar cap. and if it says so on the part then the docs are correct.
does it have to be np?
if you follow detected audio signal, the signal goes through to C41 (4.7uF/16V) a polarized ecap before entering q7-2 which is biased at 3VDC.
so you can use a polarized ecap for C86 but the -ve terminal should face towards C41 or just use a np ecap as specified for c86
you can always make a np ecap from 2 pol ecaps, just double the capacity/half the voltage and hook neg terminals together!!