Neumann KH120A noise issue ...ANYONE?

[btyreman]

finished the job this evening, the left one  is now noise free as well! super happy to be able to get back to mixing, will upload pics tomorrow of the old caps as promised.

Hopefully they'll last a lot longer than 6 years this time. ;D

 

[btyreman]

I tried to add a photo but it didn't work, it said error upload folder full?

anyway the old caps are  Yageo/ Samwha and KMG

replaced them with mostly rubycon but some panasonic and nichicon.

 

[Khron]

The KMG would be SamYoung. Either way, nothing better than "mid-range" imho.

It kinda stings to see cheapo components like those being used in >500gbp (each!!!) speakers...

 

[btyreman]

The KMG would be SamYoung. Either way, nothing better than "mid-range" imho.

It kinda stings to see cheapo components like those being used in >500gbp (each!!!) speakers...

my guess is that this is where the compromise is, the price would have to come up if they put better components in,  the caps they used were all rated to 105 degrees and as explained earlier I've used these a hell of a lot, definitely more than your average user, don't let it put you off because they are truly great speakers when working fine.

 

[Khron]

Well, that argument is neither here nor there - these aren't exactly produced in the millions, on one hand, and on the other hand, half-decent electrolytics aren't THAT pricey nowadays.

But I guess bean-counting and penny-pinching goes on at all levels...

 

[scott2000]

The KMG would be SamYoung.

I think those are Nippon or United Chemi-con  which are usually pretty decent....

But yeah...what the heck with the goofy ones?

 

[Khron]

SamYoung, for whatever reason, have several series that, coincidence or not, are named the same as Chemi-Con ones (SHL, KMG, KMF).

http://www.samyoung.co.kr/eng/product/product_miniature_series.asp

Albeit the fat 400V cap on the primary does indeed look like a ChemiCon (KMQ). All the rest have a "+" shaped vent, which is as generic as you can get (Nichicon use it too, but the "dents" usually don't reach all the way under the sleeve). ChemiCon radial caps have a Y-shaped vent (or Mercedes-3-pointed-star, whichever you prefer).

I think those are Nippon or United Chemi-con  which are usually pretty decent....

But yeah...what the heck with the goofy ones?

 

[scott2000]

Sneaky....Thanks for the info...

I get a kick out of some of these cap's names....

I can't recall the (I believe Nichicon)  one I saw before but they swapped a couple of letters...lol

 

[btyreman]

the huge cap is indeed a chemicon, I got a  japanese nichicon replacement, I did plan on removing that as well but couldn't get it out, the silicone is very thick around that one so just left it alone, also don't really have the time right now, could be a future job.

so the cost for all caps including the 400v one came to around £20 per speaker which I thought was pretty good,

I could do with a decent de-soldering gun! can't afford one right now but it's something that would have made this 10x easier. ;D

 

[moamps]

finished the job this evening, the left one  is now noise free as well! super happy to be able to get back to mixing, will upload pics tomorrow of the old caps as promised....Hopefully they'll last a lot longer than 6 years this time. ;D

Good work.
Can we finally conclude that you owe me a one Fuller’s London Pride once?

 

[btyreman]

Good work.
Can we finally conclude that you owe me a one Fuller’s London Pride once?

definitely! 

 

[user 37518]

I didn't expect to see a $3.5 amplifier chip in a Neumann speaker.... not saying its a bad thing but I expected more high end components, perhaps a proprietary part or discrete amp, although the THD specs on the jelly bean chip are ok, they are not stellar... I guess that's one good reason to buy passive monitors which are a dying breed nowadays.

 

[btyreman]

here's the photo of the old caps.

 

[Khron]

Hey, profit margins gotta come from somewhere :

Proprietary parts are expensive (R&D, small-scale manufacturing etc). And to be fair, the drivers will distort more than the electronics any day of the week, so...

Passive speakers / crossovers have their own set of... imperfections, let's say.

https://sound-au.com/biamp-vs-passive.htm

I didn't expect to see a $3.5 amplifier chip in a Neumann speaker.... not saying its a bad thing but I expected more high end components, perhaps a proprietary part or discrete amp, although the THD specs on the jelly bean chip are ok, they are not stellar... I guess that's one good reason to buy passive monitors which are a dying breed nowadays.

 

[user 37518]

And to be fair, the drivers will distort more than the electronics any day of the week, so...

That's not the point I was trying to make, an amp should be (at least IMHO) as low distortion as possible regardless of the speaker it is connected.

 

[Khron]

Well, sure, i wasn't implying that 10% THD amps would be "fine", but something run-of-the-mill with specs below the limits of perceptions should still be adequate.

I mean, these are "just" $500 a piece monitors, while there are plenty of 4-5 figure priced ones as well ;D (which might arguably warrant going that extra mile).

 

[btyreman]

have you seen the actual specs of these speakers Khron? where do you get the 10% THD figures from? 

 

[scott2000]

I think it was a figure of speech.....

 

[user 37518]

here's the photo of the old caps.

Some of the caps you replaced were perfectly good Nippon Chemicon caps.

 

[btyreman]

Some of the caps you replaced were perfectly good Nippon Chemicon caps.

probably but it was worth replacing them all at the same time, too late now, it's done, I am just happy that they're working again.