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B&W 803D crossover caps

I am considering an upgrade of the crossover capacitors in by B&W 803Ds, particularly the mid and HF coupling caps.

I took out the top bass driver to find out what caps were installed. It looks like for the diamond tweeter B&W uses a Mundorf Supreme silver/gold, 4.7 mfd 1200V. For the mid driver there are two; a 47 mfd Mundorf MKP 400V series coupling cap (in series with the driver) and a 10 mfd Mundorf Supreme siver/gold bypassing cap (parallel to the driver).

I was thinking about changing out all three, but have a few concerns.

I was going to replace the 10 mfd, 4.7 mfd Supreme silver/gold with Supreme silver/gold/oil. Would there be enough of a difference in these two types to justify the cost? I also do not want to make the upper end any brighter.

I am also concerned about the long term reliability of oil filled caps, as some failures have been reported in warmer environments. I wonder if B&W did not use the silver/gold/oils for that reason.

The biggest impact I suspect will come from the replacement of that series 47 mfd MKP. I would probably use either the Mundorf MCap EVO (Al metalization), MCap EVO oil (Al/oil), or the MCap EVO silver/gold/oil. All three are the same size for 47 mfd, and will fit to replace the MKP. Barring the issues about oil, which might be the best sounding? Again, I want to avoid too much enhancement of the upper midrange.
dhl93449
reynolds853
386 posts
 
DHL,

It's funny how these reviews go. I think at this level of capacitor it must come down to system synergy and personal preference.

I have experience only with the 630VDC version of the MR and that's the one with which I would stay. For my friend's crossover project a few weeks ago I ordered a set of MR's from PartsConnexion. They didn't have the ones we needed in stock but it only took them a couple of days to get them from their distributor. If PartsConnexion is indicating a longer delay for the values you need then you might give MadiSound a call. HifiCollective in the UK might be another source.

You mentioned the various conductive materials in your post. As I know you are aware, the MR is an aluminized polypropylene cap. I prefer the tone of the copper film caps more, but as you also mentioned in your note the cost of admission to those caps is high. To me, short of making the jump into those caps, the MR is the best out there.

I reread your original post and it looks like you need a 4.7mfd for your tweeter? I have a pair of MR 630VDC in that value that I don't use anymore since moving the crossover to Duelund CAST. I'll send you an email offline to discuss further.

Cheers,

John
dhl93449 OP
455 posts
 
Rtilden:

Based on your experience, did you find a material difference between the Mundorf M-Cap Supremes vs the SGO? I understand the "Supremes" do not contain oil, so my quandary is still SG only vs SGO vs silver oil vs "no oil". I still do not quite understand the use/impact of oil in the first place.

dhl93449 OP
455 posts
 
John:

I wanted to thank you publicly for generous offer. I will try those Carity caps when I get them.
ptss
1,964 posts
 
Thanks DH for the link. I found it interesting but did not see any post mods pics?
rtilden
156 posts
 
Dhl: My project was really different than yours, and it is not a direct comparison at all. Sorry if I failed to make that clear.

Tweeter upgrade was only drivers. I had already started with the S/G/O, so my only variable was the driver.

Midrange upgrade was only capacitors. I originally had a single Solen cap and replaced it with six Mundorf M-Cap Supremes. No further comparison. I went about as far as I could go, given the large cap values of the mids. I think that set me back about $900.

Sorry I have no direct comparisons between other caps.
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