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Wanted WTB: 1-3uf 150v wet tantalum
- Thread starter salomonander
- Start date
Help Support GroupDIY Audio Forum:
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- Mar 11, 2014
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In general I try to replace bad components in vintage gear with the same type. I've heard some U47 with new metal film resistors, new film capacitors and a new K47. The classic sound is gone. But if a tube microphone has an electrolytic cap on the output I always try to find a film cap that fits. I've never come across a failed cap in that position but they have always drifted a bit. I'm actually pretty shure I serviced that specific ELAM and if I remember correct that Siemens electrolytic had drifted to. I installed a 1uF film cap and the microphone sounds amazing, but I'm also interested in how the sound is affected with a wet tantalum.
Another aspect is how much it affects the value when the components are not the original type. Guess that depends on the buyer.
Another aspect is how much it affects the value when the components are not the original type. Guess that depends on the buyer.
iprovlek
Well-known member
iprovlek
Well-known member
And here...
https://hr.mouser.com/c/?q=vishay wet tantalum 150V 3uf
They isn't cheap, very expensive!
https://hr.mouser.com/c/?q=vishay wet tantalum 150V 3uf
They isn't cheap, very expensive!
What tube and circuit did those U47 type microphones used?
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- Mar 11, 2014
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The latest one was actually a U48, short body, VF14 tube, BV08 transformer, can't remember the other ones. To say that the classic sound was gone is perhaps a bit exaggerated but something was definately missing. I didn't enjoy the tone and neither did the client. I've rebuilt it with NOS Beyschlag resistors and Siemens MP caps. It got better but I prefer M7 in that circuit (I know U48 historically came with K47).
Way ahead of you there. Jeez - some things have gone insane price-wise. Other stuff has just been hard to get... We needed a standard input/output jacks for a certain brand of guitar amp we had in for repair... Nobody had this standard part. When the parts finally did come and our rep called to fill me in I asked how many they got in the shipment. His answer was 12 as that was all that was available! The amp I was working on needed at least a third of those - I just bought them all. I felt bad for any other repair places that needed them at the time, but we could not risk being without them. That customer had to wait three months as it was. Although, the lesson for him may have been do not replace a blown fuse in your amp with a much larger one - but that is another story. I am glad we had a few miles of silver-plated PTFE wire on hand before Covid hit, that's gone up or dried up too. I would normally say, I can look upstairs in our passive inventory for you, but I KNOW we do not have any higher voltage wet tantalums in stock. Also of note and driving some prices up - the parts with leads re either no longer being made, or no longer being stocked at the distributors to the degree they used to. Surface mount is taking over their warehouse shelf space. That drives up costs as availability goes down.
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- Mar 11, 2014
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Original
I really don’t believe or see any reason to change in an Original Neumann U48 microphone ALL the original resistors for Metal film resistors, and ALL the Film capacitors for new Film capacitors. Resistors and capacitors don’t fail bulk so that all of them need to be changed.
So you never heard any U47 microphone with new metal film resistors and new film capacitors, and can’t really comment if the Classic sound is gone or not because of that.
In my long career as a professional recording Engineer I was fortunate enough to use U47 microphones many times, and all of them sounded a little bit different, so what is the “Classic Sound” is something quite debatable and is not a concept that is really well defined and accepted by everyone.
For some reason, maybe snake oil, you want to believe that Metal Film resistors and New Film capacitors are bad or worse than the components done 70 or 60 years ago, and you made an untruthful argumentative comment to try to make it stick.
I have no doubts that changing a resistor or two for metal film and some caps for new film caps will not change whatever is the Classic Sound of a Neumann U47 microphone.
The Classic sound is a combination of the complete circuit as an whole, starting with the PSU, the Tube used and it’s state of performance (some VF14M are almost lifeless at the present after 60 years of usage), also the capsule if it is an M7 or K47 the sound will be different, saying this the Original M7 are disintegrating at this point. There’s many factors in the whole unit and circuit it will not be the precision metal film resistors or the new film cap used that will degrade its performance for sure.
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I never said that new metal film resistors and caps are bad. You made that up. They are actually better and I use them all the time. I'm definitely not a snake oil person but I think components sound different and is a part of the sound, not necessarily a good or a bad sound. I actually corrected myself in an earlier post:
"To say that the classic sound was gone is perhaps a bit exaggerated but something was definately missing."
I don't know why the well known tech that serviced the U48 before me had changed them. Perhaps he reversed a FET modification.
I've too heard and serviced a lot of U47/U48. I have eight in my shop at the moment so please don't educate me. All original M7 needs reskinning, many K47 too. The individual capsules can differ a bit in sound which can be frustrating, but if the amplifiers are healthy and from the same time period they sound close.
So I agree with you that individual U47 sound a bit different but not with those who say that they sound "waaaay different". They will if one is an old long body with cracked M7, noisy bass shy VF14, drifted resistors, leaky MP caps and GN107 transformer and the other one is a short body with a new K47, a nuvistor and perhaps even a replaced BV08 transformer. But then we're no longer comparing the same microphones.
We're completely of the topic of this thread so let's move on.
I've replaced many leaking film caps on the output of classic mics...some after they take the transformer with them, as they start to leak they can draw enough current thru the xfrmr to damage it.
I always remove old film caps from mics and test them for leakage at operating voltage with a test apparatus I designed for such purposes, if they aren't leaking I leave them in circuit.
Wet tants are $$$(always have been) and the manufacturer would not have used them if they didn't consider them necessary.
I always remove old film caps from mics and test them for leakage at operating voltage with a test apparatus I designed for such purposes, if they aren't leaking I leave them in circuit.
Wet tants are $$$(always have been) and the manufacturer would not have used them if they didn't consider them necessary.
Ah! the good old audio war about components / sound 
I replaced old tants in a km84 for new electrolytics (which plenty of people find better here it seems) it sounds like shit now!! will put old ones again right away!
I'm shocked to find exceptionally low esr on old electrolytics made in germany, not a single new one capacitor can match the performance and sound.
Old tantals sounds better than any tantal made today from personal tests. Unfortunately...
I replaced old tants in a km84 for new electrolytics (which plenty of people find better here it seems) it sounds like shit now!! will put old ones again right away!
I'm shocked to find exceptionally low esr on old electrolytics made in germany, not a single new one capacitor can match the performance and sound.
Old tantals sounds better than any tantal made today from personal tests. Unfortunately...
salomonander
Well-known member
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- 947
Thanks everybody. From doing some more research it seems to me as if they varied the components. My clients mic has a siemens elko on the output. Looks original. And the original schematic actually specifies elkos for both polarized capacitors (1-3uf and 20uf). Then again, on every picture i can clearly see that the 20uf capacitor is an ero mil-etah. Which is a wet tantalum 
i do wonder if they really used a tantalum on the output. Never seen one with a voltage rating above 125v. maybe they just used them for the 20uf?
i do wonder if they really used a tantalum on the output. Never seen one with a voltage rating above 125v. maybe they just used them for the 20uf?
Be sure to test for outside foil on new caps, not really an issue with lower impedance solid state circuitry but it can make a difference in tube gear.
