I have read time and time again various debates for this subject. Just wanting a simple-ish answer from you guys tho. I am currently building a chorus pedal which uses a ton of 1uf and other small value polarized caps. Obviously it calls for electrolytic caps, but I was wondering if I would see any benefits from using tantalums instead. I just stocked up on them and was thinking of making use of my stockpile. Some people say they should only go in distortion pedals, but my basic theory of you get what you pay for leads me to believe they will help being as they are MUCH more expensive than electrolytics.
FWIW its the topopiccione dimension c clone :icon_twisted:
4 hours into it and have the board drilled and the resistors/diodes done, along with a few jumpers and IC sockets.
I heard tanty's are horrible for audio , i'll challenge that using a 1.5uf tanty in my next gen stratoblaster .
there is at least 1 in every boss pedal i have taken apart. there has to be some reason that engineers and whoever else will approve a 60 cent part with a 5 cent part can be used.
or that is just the reason every boss pedal sounds "crappy"
They're used for their temperature coefficient, the fact that they can withstand higher temperatures and maintain the same characteristics. At the end of the day 1uF is 1uF, whether it's made out of tantulm or a tin can is kind of moot.
I suspect as well that tantalums found their way into a great many pedals during "the golden era" because they could be easily bent over and laid flat. That's certainly how MXR used them. Lying them flat meant that circuit boards could be easily stuffed inside the standard 1590B chassis that they used. I would be curious to know if there were EVER any tantalums used in any MXR products built into a 1590BB or larger chassis.
Electrolytic capacitors depend on a thin film of aluminum oxide which has a relative permittivity (dielectric constant) of 9.1 whereas tantalum pentoxide has a dielectric constant of 27. so tantalum has an immediate advantage in reduced volume for a given capacitance. You can go up to 600 volts with aluminum oxide whereas I have never seen tantalum above 75 volts. Tantalum pentoxide provides a film with very few surface defects, so this results in much lower leakage current than aluminum oxide. But tantalum pentoxide can turn into conductive tantalum dioxide at high temperature where there is a defect and since this conducts and self-heats, it turns more of the dielectric into the conductive oxide, resulting in a firestorm within the device. To eliminate this problem, the dry slug tantalum capacitor must be used with a series resistance to avoid adding enough current to cause this self-heating, so it is ideal for timer applications due to low leakage and survives in coupling applications where series resistance is normal, but it doesn't necessarily provide good sound. There are wet-slug tantalum capacitors and tantalum-case tantalum capacitors that are used for power line bypassing, but you rarely see them. Whereas aluminum electrolytics have poor characteristics at high frequencies, dry-slug tantalum is exceptionally good - but it still needs series resistance.
I have heard complaints about tantalum sound before, but I am not sure what the problem is.
Quote from: Mark Hammer on November 29, 2011, 09:20:04 AM
...I would be curious to know if there were EVER any tantalums used in any MXR products built into a 1590BB or larger chassis.
(http://files.effectsdatabase.com/gear/pics/mxr_phase100script_003.jpg)
flanger and delay used tantalums too....
In my repairing life, I've subbed almost all tantalums I faced...
Once upon a time, tantalums were fairly small for their ratings (capacitance and voltage), compared to electrolytics. They cost most, but if you could find ways to recoup the added cost, you might use them. These days, there is very little reason to need to use them, unless there is some very specific characteristic of a circuit that is aided by the properties of tantalum.
Just out of curiosity, are there tantalum SMD caps?
Yeps, SMD tantalum caps: http://hep.physics.lsa.umich.edu/alpha/images/avx_tps.pdf (http://hep.physics.lsa.umich.edu/alpha/images/avx_tps.pdf)
So are you telling me that 90% of the time I see a Tant. in the BOM of a clone I want to build I could just use a Electolytic and it would be just as good? ....... or even better? :icon_eek:
First of all, tantalum caps **are** electrolytic. Capacitors made from aluminum, tantalum, and niobium exist. They are all made by an electrolytic (!) process where the metal film is oxidized to form an insulating oxide layer in a bath of electrolytes (fluid with added chemicals to make it conduct electricity better) by an electric current.
Aluminum is cheap; tantalum oxide has a higher dielectric constant, letting tantalum caps be smaller for the same capacitance*voltage, and niobium caps are rare. I know they exist, but haven't ever seen one.
On aluminum vs tantalum, tantalum makes smaller caps, but has these quirks, not least that they can explode or catch fire under the wrong circumstances. Aluminum is cheap, so there has been a ton of work put into better processing. This has allowed aluminum caps to nearly catch up in the smallness race. Tantalum has some reputed advantages in lower ESR (better filtering) and for audio work a less grainy tone. At least that's the reputation among the Golden Ears. I can't hear a difference, but I allow it as a possibility. Aluminum's price advantage, lack of so many quirks, and improved performance have led to the condition where "electrolytic" makes everyone think "aluminum" as though there was no difference.
So:
- 100% of the time when you see a tantalum in the BOM of a clone, you can use an aluminum electrolytic if you can find one which will physically fit and not ravage your aesthetic sense. Whether it's better or not depends on what you mean by "better". Cheaper? Yep. Better sounding? Very, very hard to tell. The other tantalum quirks, exploding and catching fire, are unlikely in pedal because of the limited power available from the power supplies.
Once again......R.G. makes it crystal clear!
Thanks
Quote from: Mark Hammer on November 29, 2011, 09:20:04 AM
I suspect as well that tantalums found their way into a great many pedals during "the golden era" because they could be easily bent over and laid flat. That's certainly how MXR used them. Lying them flat meant that circuit boards could be easily stuffed inside the standard 1590B chassis that they used. I would be curious to know if there were EVER any tantalums used in any MXR products built into a 1590BB or larger chassis.
Yep, me too, I was just inside a blue face dual 15 band eq rack (fixing an oscillation bringing one channel down) and they were all over the place.
Looking at the schematic I can't see any reason why you can't replace all the 1uF and smaller polarised caps with film caps if you want. These days it's easy enough and cheap enough to buy small sized film caps up to about 2.2uF or so, back in the day it wasn't which is probably why those caps were tants.
Obviously that then leads to more debate about whether there's any sonic differences between film and tant, sorry ;D
*sniffs cork*
http://wduk.worldomain.net/pdf/ClarityCap_Technical_Report.pdf (http://wduk.worldomain.net/pdf/ClarityCap_Technical_Report.pdf)
http://www.bext.com/replace.htm (http://www.bext.com/replace.htm)
http://www.hificritic.com/downloads/APassiveRole.pdf (http://www.hificritic.com/downloads/APassiveRole.pdf)
and not to forget: http://studiozey.com/woodencapacitor/index.html (http://studiozey.com/woodencapacitor/index.html)
Just to add to R. G.'s excellent post, niobium capacitors are rare because they are usually limited to a maximum of 15 volts.
Quote from: slacker on November 29, 2011, 01:13:29 PM
Looking at the schematic I can't see any reason why you can't replace all the 1uF and smaller polarised caps with film caps if you want. These days it's easy enough and cheap enough to buy small sized film caps up to about 2.2uF or so, back in the day it wasn't which is probably why those caps were tants.
Obviously that then leads to more debate about whether there's any sonic differences between film and tant, sorry ;D
+1 to this. no reason not to use 1 and 2uf film caps.
People need to do more reading and testing. In certain places in some circuits you can hear caps most of the time higher voltage circuits than 9VDC effects.
IMO question what you read on the web, test it if you can. Don't believe what I am writing, test it, measure it etc.
One place a Tant is better than an Al electro is in the RAT feedback network. ESR is lower in lower value tants than electros. Look at the values in the two legs form _input of the opamp to ground. Try Al electros then try tants measure on a meter so the cap values are matched. The ESR of an Al electro can be a bigger portion of the resistor values in the two - to ground legs.
Smaller value (under 10uf) I like to use films or tants in my builds.
Also the voltage difference across the plates matter.
Look for The C.B. cap PDFs on the web very good reading. Shows distortion graphs of different caps and the effect of the DC voltage difference between plates.
Caps types in effects OFTEN don't matter as much because of the low voltage however some are microphonic and that can be part of the sound. something like a tone control cap in a guitar body with guitar amp speaker feedback going on. Example I installed pickups in a friends guitar and we tried different cap types and values film stacked and wound and ceramics. The sound my friend liked was the stock large disk ceramic from the 70's that was microphonic. I forget what lettering was on the cap for ceramic type.
When the dc voltage difference between plates is increased like in a guitar amp, PI to output tube(s) coupling cap(s) things can change.
Sorry kinda of a side question :icon_redface:
I have lot's of 10v caps......I always use 16v in my builds...but was wondering if using the 10v would be OK? or is 10v to close :icon_confused:
The footprint is smaller and that would be a plus in some builds.
Quote from: alparent on November 30, 2011, 11:01:21 AM
Sorry kinda of a side question :icon_redface:
I have lot's of 10v caps......I always use 16v in my builds...but was wondering if using the 10v would be OK? or is 10v to close :icon_confused:
The footprint is smaller and that would be a plus in some builds.
If the voltage in the circuit (where the cap is in the circuit) is 5vish then they should be fine and with some leeway.
If you are using them at 9v then you are pushing it. I'm sure they will be fine but your right on the edge and it would be
best to use a higher rated cap just in case.
You're right, John. 10V ought to be OK. It will be if one uses either batteries or well regulated 9Vdc supplies. A fresh alkaline battery will sometimes measure 9.4 to 9.6.
However, there is a contingent of effects users that want to "mod" effects by hooking them up to 12V or 18V. A 10V cap will be in trouble, especially at 18V. I've had to start specifying 25V caps for everything, purely out of "defensive medicine."
Quote from: Gus on November 30, 2011, 10:49:44 AM
Caps types in effects OFTEN don't matter as much because of the low voltage however some are microphonic and that can be part of the sound. something like a tone control cap in a guitar body with guitar amp speaker feedback going on. Example I installed pickups in a friends guitar and we tried different cap types and values film stacked and wound and ceramics. The sound my friend liked was the stock large disk ceramic from the 70's that was microphonic. I forget what lettering was on the cap for ceramic type.
The NPO ceramic discs are not microphonic, but they are bigger.
Quote from: John Lyons on November 30, 2011, 11:37:35 AM
Quote from: alparent on November 30, 2011, 11:01:21 AM
Sorry kinda of a side question :icon_redface:
I have lot's of 10v caps......I always use 16v in my builds...but was wondering if using the 10v would be OK? or is 10v to close :icon_confused:
The footprint is smaller and that would be a plus in some builds.
If the voltage in the circuit (where the cap is in the circuit) is 5vish then they should be fine and with some leeway.
If you are using them at 9v then you are pushing it. I'm sure they will be fine but your right on the edge and it would be
best to use a higher rated cap just in case.
If voltage
rating (a cap can handle) goes down with time, wouldn't it be more secure to have some margin there ?
--------------
Also, an other question: Is it true that smaller aluminum electrolytics have less time life, this due to thinner electrolytic layer ?
I bought some 1uf film caps recently, because when all it's doing is coupling signal, electrolytic is just overkill anyways (IMHO).
Save 'em for power supplies and filters.
BTW - those 1uf film caps were TINY.
I opened up the package and was like "Holy crap, did I order 1pf's accidentally?".
Nope, and they work just fine.
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=46663&g2_serialNumber=2)
Woops, maybe I should have paid more attention to the tolerance.
+80/-20%? :icon_eek:
http://www.mouser.com/ProductDetail/TDK/FK28Y5V1C105Z/?qs=liFJyUJTUDGDO4oJ7GLD1w%3d%3d
Quote from: edvard on November 30, 2011, 01:33:11 PM
I bought some 1uf film caps recently, because when all it's doing is coupling signal, electrolytic is just overkill anyways (IMHO).
Save 'em for power supplies and filters.
BTW - those 1uf film caps were TINY.
I opened up the package and was like "Holy crap, did I order 1pf's accidentally?".
Nope, and they work just fine.
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=46663&g2_serialNumber=2)
Woops, maybe I should have paid more attention to the tolerance.
+80/-20%? :icon_eek:
http://www.mouser.com/ProductDetail/TDK/FK28Y5V1C105Z/?qs=liFJyUJTUDGDO4oJ7GLD1w%3d%3d
That's a multilayer ceramic dude :icon_exclaim:
Aw, cripes... I totally missed that.
All this talk of film and I got carried away...
Anyways, they "sound" just fine, though I think I'd spend a little extra for better tolerance next time.
Quote from: edvard on November 30, 2011, 03:10:44 PM
Aw, cripes... I totally missed that.
All this talk of film and I got carried away...
Anyways, they "sound" just fine, though I think I'd spend a little extra for better tolerance next time.
Multilayer ceramics ... They are absolutely microphonic , any nearer to my amp and crazy feedback occurs .
By my understanding, tantalums don't degrade over time the same way aluminum electrolytics do. We're talking 10 or 15 years down the road before electrolytics could potentially start going bad, but if you can get away with all tantalums in your design (e.g. the Keeley Compressor) then you're not going to have to replace the caps later. It's not that big a deal for us DIYers to have to change the caps a decade from now, but with all the tantalum hate, I thought I'd at least say something positive :)
This really only applies to caps from 3.3uF to about 22uF, though, because any smaller can be handled by film, and tantalums are hard to come by at higher values than 22 if you want to keep a safe voltage rating.
> tantalums don't degrade over time
My observation is that Aluminum electros die "quietly", maybe some ooze leaking; but Tantalum electros will sometimes die with a BANG. And older Tants seem to have a 20-year timer.
Most places we used Tant in the 1970s-1980s, today's improved Aluminum caps are IMHO a Better Part.
Oddly enough, I'd always heard that electrolytics sound awful and tantalums great. I haven't done enough part swaps to form a valid opinion, but I strongly suspect that in normal circumstances with modern parts, a capacitor is a capacitor. Maybe I'll experiment with a recording and some socketed caps.
Quote from: jafo on December 01, 2011, 12:01:06 AM
Oddly enough, I'd always heard that electrolytics sound awful and tantalums great. I haven't done enough part swaps to form a valid opinion, but I strongly suspect that in normal circumstances with modern parts, a capacitor is a capacitor. Maybe I'll experiment with a recording and some socketed caps.
I mean , seriously , after using electrolytics everywhere , how could you say electrolytics sound awful ? that's just wrong .
Quote from: DavenPaget on December 01, 2011, 03:12:07 AM
Quote from: jafo on December 01, 2011, 12:01:06 AM
Oddly enough, I'd always heard that electrolytics sound awful and tantalums great. I haven't done enough part swaps to form a valid opinion, but I strongly suspect that in normal circumstances with modern parts, a capacitor is a capacitor. Maybe I'll experiment with a recording and some socketed caps.
I mean , seriously , after using electrolytics everywhere , how could you say electrolytics sound awful ? that's just wrong .
Agreed (although economics can justify suboptimal common practice). But I think I'm more disturbed that so few people are willing to do even basic experimentation.
Hi
re: little ceramics
QuoteMultilayer ceramics ... They are absolutely microphonic , any nearer to my amp and crazy feedback occurs .
This is very unlikely if they are used for power supply isolation (e.g. near op-amps). In general, the feedback is physical and suitable mounting/packing of the board can greatly help. I've used them widely in low gain circuits for filtering and feedback, including in commercial applications, without problems.
Expanding on this - except for Gus' contribution, this thread has mostly lacked discussion of the use and purpose of the caps. Context helps lots. Otherwise we're having a discussion along the lines of: motorcycles or trucks -which are best?
cheers
Quote from: brett on December 01, 2011, 07:22:35 AM
Hi
re: little ceramics
QuoteMultilayer ceramics ... They are absolutely microphonic , any nearer to my amp and crazy feedback occurs .
This is very unlikely if they are used for power supply isolation (e.g. near op-amps). In general, the feedback is physical and suitable mounting/packing of the board can greatly help. I've used them widely in low gain circuits for filtering and feedback, including in commercial applications, without problems.
Expanding on this - except for Gus' contribution, this thread has mostly lacked discussion of the use and purpose of the caps. Context helps lots. Otherwise we're having a discussion along the lines of: motorcycles or trucks -which are best?
cheers
You were saying ?
http://greygum.net/sbench/sbench102/caps.html (http://greygum.net/sbench/sbench102/caps.html)
Quote from: DavenPaget on December 01, 2011, 07:36:15 AM
Quote from: brett on December 01, 2011, 07:22:35 AM
Hi
re: little ceramics
QuoteMultilayer ceramics ... They are absolutely microphonic , any nearer to my amp and crazy feedback occurs .
This is very unlikely if they are used for power supply isolation (e.g. near op-amps). In general, the feedback is physical and suitable mounting/packing of the board can greatly help. I've used them widely in low gain circuits for filtering and feedback, including in commercial applications, without problems.
Expanding on this - except for Gus' contribution, this thread has mostly lacked discussion of the use and purpose of the caps. Context helps lots. Otherwise we're having a discussion along the lines of: motorcycles or trucks -which are best?
cheers
You were saying ?
http://greygum.net/sbench/sbench102/caps.html (http://greygum.net/sbench/sbench102/caps.html)
I think Brett was addressing your assertion of microphonic behaviour. Your link (and subsequent links) has absolutely no data regarding microphonics.
Assertion ? :icon_mrgreen:
You kidding bro ? i have a stratoblaster with a 1.5uf output monolytic and it is very microphonic .
http://www.electro-tech-online.com/general-electronics-chat/26407-electrolytic-caps-vs-tantalum-caps.html
not all ceramic caps are created equal.
5 cent jelly beans in high capacitances will most likely suck in all ways.
that 80/20 tolerance isn't so hot either.
on the other hand a nasa quality space approved .1 tolerance glass porcelain cap will be the tits.
I have to say that NOT 100% of the 9-Volt stompboxes are "are indifferent" to the type of electrlytics.
For example, the famous Harmonic Percolator and it's numerous clones work absolutely different with one of their caps changed with Tantalum/Alu.
Quote from: diagrammatiks on December 02, 2011, 01:18:14 AM
not all ceramic caps are created equal.
5 cent jelly beans in high capacitances will most likely suck in all ways.
that 80/20 tolerance isn't so hot either.
on the other hand a nasa quality space approved .1 tolerance glass porcelain cap will be the tits.
Not all tantalums are created equal, either. The most common are the dry-slug tantalums which have the characteristics that have been mentioned: low leakage current, excellent high-frequency performance, small size, inability to self-healand tendency to explode when fed by a low-impedance source like a power supply. There are also wet-slug tantalums which are able to be used on power supplies but will short out if subjected to more than 0.3 volts in a reverse direction. There are tantalum foil capacitors which are usually available in larger capacitances and sacrifice high-frequency behaviour for compact size. Then there are tantalum-case tantalum capacitors that are excellent for power supply bypassing. I used these on a power supply filter for the Shuttle-mounted power supply "dock" for the Hughes GOES series satellites and the attenuation came within 1 db everywhere and 0.5 db in most places.
Quote from: diagrammatiks on December 02, 2011, 01:18:14 AM
not all ceramic caps are created equal.
5 cent jelly beans in high capacitances will most likely suck in all ways.
that 80/20 tolerance isn't so hot either.
on the other hand a nasa quality space approved .1 tolerance glass porcelain cap will be the tits.
I use space rated multilayer and parallel plate ceramic caps with gold bond terminations in high frequency cryogenic amps for radio astronomy every day, and yes, they are the tits.
These guys make awesome stuff http://www.atceramics.com/ (http://www.atceramics.com/)
This is a link to some of the best PDFs about caps on the web.
http://main.diycore.com/index.php?categories=Passive%20Components
I was looking at some old solid state amp schematics (Sunn Coliseum 300) and I see stuff like 10/NP a lot. I assume this means 10uf non-polarized. I also assume this means tantalum caps. Can anyone surmise why in an amp that has plenty of room for larger electrolytics the designers would choose not too use them? These caps are in the signal path as well.
$
depends what you've got in stock, bulk deals special offers, etc.
was a bit of a flippant post, sorry. just a cynical guess. s'pose the way to tell would be to compare two versions of the same model manufactured at different times.
So what I am getting from this thread is that they are great and they sound like $h!t :icon_rolleyes:
Tants ... They tend to blow up easily :icon_mrgreen:
> solid state amp schematics (Sunn Coliseum 300) and I see stuff like 10/NP a lot.
What power supplies?
Bipolar (+/-) supplies allow opamp outputs and inputs to sit at zero volts DC. However it's never exactly zero; also we don't want DC flowing through. So there's blocking caps. The "zero DC" could be off a fraction of a volt in either direction + or -. So a non-polar cap is needed. The resistances are often low, under 10K, so a large cap is needed, bigger than a practical film-cap. Anyway 10uFd electro is cheaper than 1uFd film ("$"). So they spray 10uFd non-polar electrolytics.
These will normally be aluminum, not tant.
Quote from: PRR on December 03, 2011, 04:29:37 PM
> solid state amp schematics (Sunn Coliseum 300) and I see stuff like 10/NP a lot.
What power supplies?
Bipolar (+/-) supplies allow opamp outputs and inputs to sit at zero volts DC. However it's never exactly zero; also we don't want DC flowing through. So there's blocking caps. The "zero DC" could be off a fraction of a volt in either direction + or -. So a non-polar cap is needed. The resistances are often low, under 10K, so a large cap is needed, bigger than a practical film-cap. Anyway 10uFd electro is cheaper than 1uFd film ("$"). So they spray 10uFd non-polar electrolytics.
These will normally be aluminum, not tant.
Thanks. Learn something knew everyday!
Quote from: Bill Mountain on December 03, 2011, 01:56:03 PM
I was looking at some old solid state amp schematics (Sunn Coliseum 300) and I see stuff like 10/NP a lot. I assume this means 10uf non-polarized. I also assume this means tantalum caps. Can anyone surmise why in an amp that has plenty of room for larger electrolytics the designers would choose not too use them? These caps are in the signal path as well.
non-polarized can be electrolytics as well.
since they are in the signal path they should ideally be non-polarized.
> non-polarized can be electrolytics as well.
Both Aluminum and Tantalum are "electroltic".
In causual conversation, "electrolytic" usually means Al; if there is some reason to pay much more for Tantalum, we get specific.
> since they are in the signal path they should ideally be non-polarized.
Signal caps with any significant and reliable-polarity DC across them, such as coupling caps in uni-polar supply applications, can (and usualy should) be simple "polarized" caps, not the more complex and expensive non-polar type. Even with huge AC/Audio voltages, the voltage across the cap does not reverse.
I've also found non-polar caps to be less reliable, but that may just be bad luck.
Hi
Let me be really clear. I don't care about non-linearity and microphonics in caps not carrying my signal. Non-signal caps should be big in uF, small in size, cheap and reliable.
In particular, the small size of those multi-layer ceramics make them perfect for decoupling the PS near op-amps. As we all know, proximal de-coupling of every op-amp is good practice.
A cheap, tiny, dry, non-polar, 1uF (ie multi-layer ceramic) cap is more-or-less perfect.
cheers