C1 capacitor in U47

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o3misha

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Joined
Nov 20, 2012
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229
Hi all! There were some different types of C1 capacitor in Neumann U47. I saw  ceramic and film C1 caps in U47 . There may have been some other, but I have never met.  Did Neumann used the PIO capacitors C1 or not? Has anyone tried different types of capacitors  C1? What are your preferences?
Thanks to all who responded to my questions.
 
Hi, thank you for answer. I tried many types of C1 except ceramic because of it's microphonic. I found that C1 is most important cap in U47. Most interesting sound for me with Duelund VSF Cu cap 0.01UF/400VDC. It's expensive, but it improves the sound very much. A little less I like polystyrene(polyester) capacitors. They are a little more emphasize sibilance, but not bad. Polypropylene capacitors give a neutral sound, but there is a little dirty shade in the upper frequencies. The paradox is that it is not always the best in terms of dissipation factor, and dielectric absorption capacitor will work better in the microphone.
 
I guess I should have asked: what capsule are you using?

Is the rest of the circuit truly authentic? VF14?

I only ask because phrases such as 'emphasize sibilance' could be misleading.  :)

 
Microphone is original Neumann U47 with re-skinned PVC M7 Neumann/Berlin capsule ( repaired by S.Thiersh). After re-skinning capsule sounds terrific. The tube - VF14 M. I've got pair of U47s. Both had original ceramic C1. BTW, I'm talking about very small difference in sound. There are sibilanсe,-  and there are SIBILANCE. If you compare  two different M7 caps you will find much more differences then between two types of C1, of course.
 
Ah, so you're looking to optimise the flavour to your preference, rather than to copy or restore ...

Like you, I have only seen ceramic (disc, I think?) and film types (those gold cylinders that look similar to the WIMA caps in Vox amps).

My preference for the film types is more or less based purely on their low microphonics, plus I think that they sound a little 'smoother' in the upper mids and top end - I have a possibly psychosomatic belief that ceramic sounds 'grainy' - but you might disagree, and that's totally fine! :)

 
Yes, I agree. Film capacitors much more neutral than the disc ceramic. But I went ahead and tried the super-modern technologies, which are applied in Duelund caps. Sound becomes erotic! Very beautiful and musical top. Perfectly amenable to equalization. Soft balanced bottom, without boominess and smooth mids. It's amazing how such a small detail can so affect the sound. I do not regret a single second spent on Duelund cap money. I highly recommend it to everyone.
 
Duelund VSF Cu 0.01uF/400VDC I don't remember the price, but it was ~125-150 Eu. I must say that I do not regret buying at least once.
 
No typo. Its expensive cap, realy. http://www.partsconnexion.com/capacitor_film_duelund_vsf_electronic.html
 
Misha, did you complained to mr Thierch? I'm sure he can tweak tension to your needs. It will be more elegant than to change the original cap. Also, don't get me wrong but spending such amount of money for  single 0.1u cap sounds a bit audiophoolistic :/
 
I had a lot of M7's. Believe me, the replacement of C1 introduces a completely different change in sound. I do not think the price high, by the way. You just never tried it, so say so. I decided to take a chance, though, and I was skeptical as you are . But, finally -no regrets. The original capacitor? Original cap was ceramic, which was microphononic and had roughness treble. Neumann used them as the most popular cheap cap at that time. We can now enjoy many years of experience in studies of the effects of capacitors in the signal chain. Science does not stand still. So why hold on to the old one?
 
o3misha said:
I had a lot of M7's. Believe me, the replacement of C1 introduces a completely different change in sound. I do not think the price high, by the way. You just never tried it, so say so. I decided to take a chance, though, and I was skeptical as you are . But, finally -no regrets. The original capacitor? Original cap was ceramic, which was microphononic and had roughness treble. Neumann used them as the most popular cheap cap at that time. We can now enjoy many years of experience in studies of the effects of capacitors in the signal chain. Science does not stand still. So why hold on to the old one?
Then you have to experiment with old Bosch MP  (metal paper) 1u (or 0.5u). That's also ugly old technology cap ;) Yes. I never tried to replace C1 in U47 because it works as it should. There is a lot more "ugly old" things inside this  legendary microphone what "ruins" the sound . Hope that U will not upgrade the BV8 :/ BTW, here is the pic from my U47 just to point cap I'm talking about.
 

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Your opinion is common. But you need not sarcastic. And cringe. I'm quite happy with the original Bosch capacitors which are not terrible at all. The more a transformer, which is made perfectly. But even Neumann changed  type of capacitors in  U47 with the development of technology. I just found a component that works without changing anything in the general character of the sound, but a little better for me. Not in any way do not impose my views to anyone, but I think my position correct.
 
Yes,  sarcastic because it's beatifull  piece of gear as stock. BTW they changed MP cap to something else because Bosch production stopped, not because of upgrade. Regarding ceramics , yes it's microphonics, it adds some distortion and there was "better" components in that value in 40's and 50's but they used ceramics. At the end I'm just chiming not to ruin something what's wrks and also is historically correct. For that price  you can buy minimum 3 good modern U47 like microphones and save this one from upgrade. But it's yours you can do whatever U like  :)
 
To finally answer without sarcasm. You mentioned that mike became terrible after re-skinning.  So that;s the answer of your problem sound vise. It's obvious that you like less tensioned skin of the capsule what's piece of cake for mr S.Thiersh. Also, if you tried to replace ceramics cap with some other brand you will notice a sound change again. I experienced that in Marshall amp eq section. BTW do you have enough space for Duelund?
 
o3misha said:
After re-skinning capsule sounds terrific.

@ Moby: not terrible, terrific . Although etymologically related, terrific means the exact opposite: great, excellent.

Personally, I think EUR 125 is a lot for any type of capacitor in relation to what it is, i.e. a roll or stack of foils with two leads. I don't even know what type of C1 is in my U47, and so far I was too lazy to open it as I love the way it sounds.

Over the years, I've come to realize that there's no such thing as a "safe" choice of high quality cap that's best for all applications. There are various types of ceramic caps, and some can sound pretty good, actually. I've liked NP0 caps in some mics and hated them in others. Also, in some mic circuits, electrolytic and tantal output caps can give the sound an engaging quality that's lacking when you "upgrade" to a better quality film cap. Recently, I tried a high quality polystyrene as a tone cap in a guitar and hated it.

AFAIK Neumann never used anything but Bosch MP Caps in the U47 for output and anode voltage smoothing. The early ones had rectangular ones, later ones cylindrical ones, but the dielectric was the same. The output cap value changed, though (1u and .5u). Those caps are high quality and very durable - and certainly more expensive than electrolytics. Proof that they didn't use just any cheap cap. So maybe there was reason for C1 being ceramic.
 
useme2305 said:
Rossi said:
I don't even know what type of C1 is in my U47, and so far I was too lazy to open it as I love the way it sounds.

:eek: :eek: :eek:

Let me put this differently: I did open my U47 once or twice to check its condition (as you should, when you buy one) but I was too lazy, so far, to open it again for the sake of this discussion.
 
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