solid aluminium capacitor = tantalum?
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RuudNL
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It seems Neve used tantalium capacitors for a special reason.
According to Geoff Tanner (ex Neve) the sound changes if you replace the tants by aluminium capacitors.
As he puts it: "Those tants aren't there without a reason".
(Don't know how true this is. Personally I never heard much difference. Maybe it is the same discussion as with speaker cables...)
According to Geoff Tanner (ex Neve) the sound changes if you replace the tants by aluminium capacitors.
As he puts it: "Those tants aren't there without a reason".
(Don't know how true this is. Personally I never heard much difference. Maybe it is the same discussion as with speaker cables...)
jtvrdy
Well-known member
so the cap in the atached picture is tantalum?
If we go into the way back machine tantalum caps had lower ESR than aluminum caps so were better for some applications. BUT modern aluminum caps now have lower ESR than before (especially the aluminum caps designed for use in switching PS).RuudNL said:
The type of electrolytic cap used shouldn't change the circuit's sound, but perhaps they were used across PS rails without HF caps (like ceramic disc) in parallel. Another place where tantalum vs aluminum might be audible is in a dynamics time constant circuit. Tantalum was notorious for higher dielectric absorption than aluminum so could alter release characteristics in a compressor.
For most general applications I suspect a modern aluminum cap would be fine.
JR
zamproject
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If Studer say solid alu it's not a tantjtvrdy said:
http://www.vishay.com/docs/28354/128salrpm.pdf
Zam
RuudNL
Well-known member
I fully agree with you, but still some people think they hear a difference in sound...JohnRoberts said:
(In my opinion you think you hear it, because you know something has changed!
But I suppose the discussion about the 'sound' of capacitors will go on for ever.)
RuudNL said:
This has been well studied and there was a good series of articles about caps linked to a whole back. Also Sam Groner has done some serious measurements of distortion mechanisms in electrolytic caps. We can measure distortion a lot smaller than I can hear.
I try not to argue with people about what they say they hear on the internet, but the bigger the audible difference they claim, the less likely I am to believe them.
JR
Andy Peters
Well-known member
zamproject said:If Studer say solid alu it's not a tantjtvrdy said:
http://www.vishay.com/docs/28354/128salrpm.pdf
Zam
Get 'em before they're gone! Last time buy is the end of this year.
So TFDS sez: this cap has a ridiculously-long life at way high temperatures: 20,000 hours at 125 C. Useful life at 40 C (which is still pretty warm) is > 300,000 hours. You won't find a standard aluminum can electrolytic with that kind of lifetime.
ESR is pretty high, though: 100 ohms at 100 Hz.
Dunno where it's used in that tape machine, but my guess is that Studer valued the part's lifetime over all other considerations. And it can withstand fairly high reverse voltage (30% of rated working voltage), which is a condition that would cause standard tantalum caps to explode.
-a
Andy Peters
Well-known member
jtvrdy said:
The data sheet is in Zam's post, below. As for the question, "is rated at 40v or 25v?" the answer is yes
RTFDS. At 85 C its rated working voltage is 40 V. At 125 C it is derated to 25 V. The difference is possibly suggested by case size; there is a smaller part which specs only 25 V at 85 C.
I mostly agree with Cyril Bateman and other authorities on capacitor THD. In most cases, even evil electrolytic THD is inaudible in sensibly designed circuits.
But there is one application where the audible difference between Tantalums and Aluminium Electrolytics is NOT insignificant. Tantalums are truly EVIL for very low noise.
I first encountered this circa 1980 in a MC head amp with noise around 0.28nV/rtHz (ie state of the art noise performance). The latest was in a microphone design of mine built by someone this year.
As an ex-Calrec man, I'll claim Neve's love of Tantalums is one reason for their sh*t sound. ;D
________________________
For other applications, if you feel capacitors make a huge audible difference, you need to try one from Cooktown Recording & Ambisonic Productions. Send me US$100 in used bank notes (no Confederate money please) for a sample.
They are hand carved from vintage Unobtainium recovered by Virgin Ama divers from US planes shot down by the IJN in the Battle of the Coral Sea.
YOU WILL NOT BE DISAPPOINTED!
________________________
PS Any modern aluminium electrolytic of vaguely the same value & voltage rating and fits in the available space ... from the major makers like Panasonic will be a suitable replacement for your solid Aluminiums. Do not replace with Tants!
But there is one application where the audible difference between Tantalums and Aluminium Electrolytics is NOT insignificant. Tantalums are truly EVIL for very low noise.
I first encountered this circa 1980 in a MC head amp with noise around 0.28nV/rtHz (ie state of the art noise performance). The latest was in a microphone design of mine built by someone this year.
As an ex-Calrec man, I'll claim Neve's love of Tantalums is one reason for their sh*t sound. ;D
________________________
For other applications, if you feel capacitors make a huge audible difference, you need to try one from Cooktown Recording & Ambisonic Productions. Send me US$100 in used bank notes (no Confederate money please) for a sample.
They are hand carved from vintage Unobtainium recovered by Virgin Ama divers from US planes shot down by the IJN in the Battle of the Coral Sea.
YOU WILL NOT BE DISAPPOINTED!
________________________
PS Any modern aluminium electrolytic of vaguely the same value & voltage rating and fits in the available space ... from the major makers like Panasonic will be a suitable replacement for your solid Aluminiums. Do not replace with Tants!
ricardo said:
Just to be clear are you talking about Johnson (thermal) noise from the ESR, or current leakage noise from a DC bias?
I once black balled an electrolytic cap for leakage noise in a mic preamp phantom blocking,,, I suspect it wasn't properly formed in during manufacture or something like that.
JR
I don't know for sure but I don't think its either Johnson hiss or current leakage. Tants have very low leakage though by 1980, some aluminiums (eg the Panasonic Lo Leakage) would rival them.JohnRoberts said:
from 1980 "Tants give a crackly, popcorn almost like 1/f noise or insufficient dither. "
from 2015 "He found if C1 is a Tantalum, it is prone to whooshy LF noise"
Neither of these are Golden Pinnae imaginings. You just need to feed the DUT into something with enough gain to clearly hear the noise floor without other distractions.
If anyone has a theoretical explanation, I'm all ears.
BTW, the noise of different Aluminium electrolytics sound different in this 0.28nV/rt(Hz) situation but the noise of the Tants was objectionable.
I should try to replicate the tests in da 21st century now that its easy to do spectral plots of noise 8)
jtvrdy
Well-known member
Thanks Zam ! I will look at this Vishay 128 sal-rmpzamproject said:If Studer say solid alu it's not a tantjtvrdy said:
http://www.vishay.com/docs/28354/128salrpm.pdf
Zam
zamproject
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jtvrdy said:Thanks Zam ! I will look at this Vishay 128 sal-rmpzamproject said:If Studer say solid alu it's not a tantjtvrdy said:
http://www.vishay.com/docs/28354/128salrpm.pdf
Zam
you'r welcome.
There is a chance it's the same Philips (rebranded Vishay)
Zam
I would be suspicious of granularity in the current leakage. I have seen problems with aluminum before.ricardo said:
If leakage related it can be modulated by DC bias and termination resistance, so should be easy to parse out if you bench test.
FWIW the bad (noisy) aluminum caps were discovered by factory QA workers just using their ears.
JR
madswitcher
Well-known member
Tants - avoid the little buggers.
Always go short on me particularly when put across the PSU rails - grrrrr
Mike
Always go short on me particularly when put across the PSU rails - grrrrr
Mike
Tantalum is also a conflict mineral so another reason to avoid, while Dodd-Frank legislated that vendors certify their supply chain. One cap manufacturer bought their own tantalum mine to prove where it is coming from.madswitcher said:
Yes the old ones had a bad habit of failing short circuit and testing the current limit of power supplies. I haven't used tantalum for decades so don't know if new ones show the same bad manners. Certainly think twice before putting them across PS rails.
JR
That's a tant cap. Studer docs are made by humans. Replace like with like and get on to the music.
The Studer multitrack manuals are full of misprints and language errors. Prove me wrong.
Mike
The Studer multitrack manuals are full of misprints and language errors. Prove me wrong.
Mike
zamproject
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sodderboy said:
My first look tell me the same, I'm sorry to contradict you ,but in this case it's an SAL Philips (now Visay) in pearl package (like most tants) , I link the datasheet in previous post.
Zam
