Mundorf aluminum oil mcap for b&w

[Deepinton]

Anyone here know where I could source mundorf 22mf 800v dc capacitors? Are there other viable substitutes? I did a websearch and came up with nothing.

 

[voodooless]

Just use any MKP/MKT cap… don’t bother with audiophile nonsense caps like that, they are a waste of money.

See for a full series on the topic:

Capacitor upgrade in crossover - You CAN'T handle the TRUTH! - Part 3

So, after the topic capacitor upgrade has already been discussed by me in two parts, there is no reason to talk about it anymore - or is there? The full mini series: Capacitor upgrade in crossover - Is it audible? Capacitor upgrade - part two Capacitor upgrade - part three...

www.audiosciencereview.com

 

[Deepinton]

Just to be clear, I am not trying to upgrade. I suspect one of these to be dead on the MF crossover board and am trying to line up sources for an exact replacement. I may just have to use a more readily available 22uf 400v capacitor. Thanks for the response and the link

 

[NTK]

Madisound has the 700 V version.

Mundorf Supreme EVO Oil Capacitor 22 mfd

Mundorf Supreme EVO Oil Capacitor 22 mfd

www.madisoundspeakerstore.com

 

[voodooless]

I suspect one of these to be dead on the MF crossover board

Make sure it’s actually defective first. These things are prett bulletproof and do not easily break. Get a cheat LRC meter, and measure!

And if it failed, the next question is: why?

And note that a normal MKP cap is way more reliable than those audiophile Oil caps.

 

[Deepinton]

Yeah, I am waiting on some copper wick to desolder one of the legs and test. But I can visually see a faint dried streak down the side of one of those caps. A new MF board like this runs about $800

 

[Deepinton]

And needless to say, my mid is not receiving any signal

 

[voodooless]

Well, at least that pretty much confirms that it’s broken.

I would still recommend replacement with a generic MKP cap. They are more reliable, cost less and offer the same performance.

Oil leakage and drying are two of the most common failure modes of these kind of caps, it seems.

 

[Deepinton]

Here's a picture of that cap.

 

[Roland68]

Anyone here know where I could source mundorf 22mf 800v dc capacitors? Are there other viable substitutes? I did a websearch and came up with nothing.

As far as I know, they are no longer available (perhaps for good reason?), and were likely only accessible to manufacturers.
That may have been a relatively low-cost series.

You could inquire with Mundorf about replacements.
There are various alternative suppliers for such capacitors; if you are looking for an audio-grade capacitor, Intertechnik would be my first choice.

Personally, I would recommend replacing all installed 22µF 800V DC M-Caps with Vishay/Roederstein, TDK, or Kyocera 22µF MKP (PP) 1100–1300 VDC industrial capacitors—at a cost of approximately €12–20 per unit. They should also last longer.

 

[DVinylfan]

Ignore me; I'm only here for the caps rolling debate that inheres in this thread

 

[Deepinton]

As far as I know, they are no longer available (perhaps for good reason?), and were likely only accessible to manufacturers.
That may have been a relatively low-cost series.

You could inquire with Mundorf about replacements.
There are various alternative suppliers for such capacitors; if you are looking for an audio-grade capacitor, Intertechnik would be my first choice.

Personally, I would recommend replacing all installed 22µF 800V DC M-Caps with Vishay/Roederstein, TDK, or Kyocera 22µF MKP (PP) 1100–1300 VDC industrial capacitors—at a cost of approximately €12–20 per unit. They should also last longer.

But these Mundorf's look so nice

 

[Deepinton]

Another question. If I do replace with a "normal" cap that has 5% tolerance compared to 2%, would I need to do the same to the other speaker to make them matched pair?

 

[Roland68]

But these Mundorf's look so nice

Realistically speaking, what was the actual operating time of this capacitor—in hours—before it failed? That is, the amount of time during which it was actually receiving a signal.

 

[LTig]

Another question. If I do replace with a "normal" cap that has 5% tolerance compared to 2%, would I need to do the same to the other speaker to make them matched pair?

No. Better get a cheap capacitance meter and measure the cap in the working speaker, then try to find a cap with similar value. You can also buy a cap with a little less capacitance and then add smaller caps in parallel until you reach the correct value.

Edit: I'm wondering why the original cap has a rating of 800V. That would match a speaker with a rating of 39 kW peak at 8 Ohm, if I'm not mistaken.

 

[LTig]

But these Mundorf's look so nice

Can you see them in the box while playing music?

 

[Deepinton]

Can you see them in the box while playing music?

No, but now that I have seen them, I can't unsee!

 

[Deepinton]

Realistically speaking, what was the actual operating time of this capacitor—in hours—before it failed? That is, the amount of time during which it was actually receiving a signal.

The speakers were built in 2019. I would expect the much ballyhoo'ed premium mundorf to last way more than say 4 hrs a day times 1800 days

 

[Deepinton]

No. Better get a cheap capacitance meter and measure the cap in the working speaker, then try to find a cap with similar value. You can also buy a cap with a little less capacitance and then add smaller caps in parallel until you reach the correct value.

Edit: I'm wondering why the original cap has a rating of 800V. That would match a speaker with a rating of 39 kW peak at 8 Ohm, if I'm not mistaken.

I thought about this, but removing the crossover is quite involved and I gotta desolder the cap to measure it and worry about the error margin on the meter. The squeeze may just not be worth the juice

 

[MAB]

Another question. If I do replace with a "normal" cap that has 5% tolerance compared to 2%, would I need to do the same to the other speaker to make them matched pair?

You have 802D?

Here is a comparison of an 8 Ohm driver in series with a 22.0 uF capacitor, a 22.44 uF capacitor (2% high), and a 23.1 uF capacitor (5% high). The driver frequency response measurement is real, the 6dB/oct crossover is simulated with these capacitor values.

The differences are negligible, like 0.1 dB differences. Most filters are pretty tolerant to variation, even as large as 10%. Most caps are not at one end or the other end of a tolerance band. There are exceptions, like certain notches require some care. But I think you are just fine on matching.

That being said, you have a demonstrated reliability issue. The caps were likely sourced to B&W, small batch. The caps are likely siblings and may share the same defect that led to your issue.

They are trivially replaced with many as good or better capacitors from Panasonic, WIMA, etc. The cost is 10 monies each instead of 100. If it was me, I would buy half-dozen of them, match them with an capacitance meter, and replace the left and right crossover with the closest matched pair. Not because you can hear the above difference, but because I think you have some peace of mind to recover. It is also a straightforward fix for most people, which is an important consideration.

Good luck. I think you have this under control.