S75 crossover parts question

[Nicholas Valdés]

I have a pair of S75 speakers that I quite enjoy and wanted to take the time to throw new caps in them. Run into a couple questions:

1. The original caps from W. Germany are still in. Service manual (see below) states a 50uF cap @ C1 & C5. In both locations there is a 47uF. I have both values of identical npe in stock but is there a best practice?

2. The original resistors I’ve read to be in need of replacement. All are 3W resistors. Is there a baseline W rule of thumb for resistors in crossover? I have a bunch of 10W resistors that will work and fit, albeit tightly. Maybe 10W is overkill.

3. Lastly to reach some of the needed cap values I’m adding two smaller caps. Is it best to keep cap values similar when doing this? Ie on a different job I needed a 28uF and opted for 22+6.8 over 12+15 to keep it closer to original spec with what I had on hand but perhaps I should have gone with the latter.

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[AdamS]

As I said on the other forum you posted this question on:

(a) Don’t worry about the resistors

(b) Buy the correct capacitor kit from Danish Sound Parts!

[Dillen]

Don’t increase the wattage of the resistors.
Some of them double as “overload fuses” to protect the drivers.
If the resistors are not burned or physically damaged, I would leave them well alone. They will be fine.

47uF or 50uF (depending on OEM) doesn’t matter much, seeing as the tolerances of the original caps
were typically +/- 20%, and you can find them fitted randomly from factory.

Martin

[Author]

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