Is there any reason to use poly film caps over mylar film?
I know metal film caps can reduce noise in some circuits. Is there any other advantage or disadvantage to them?
What are the pros and cons of each type?
EDIT: I guess i should put ceramic disc in there also. I never use them because i heard they may cause a harsh sound. When can you use them "safely" and when should you avoid them?
Let's add polarized tantalum caps to the list. Are they any better or worse than the radial electrolytic caps?
Tantalum caps are a big no no in audio circuits. avoid them at all costs. they add noise and have an "unpleasant tone".
Quote from: MmmPedals on March 12, 2010, 10:53:03 AM
Tantalum caps are a big no no in audio circuits. avoid them at all costs. they add noise and have an "unpleasant tone".
Thanks for answering that concern of mine. My dad gave me some and said they don't "leak" like radial electrolytic caps but I was reading how tantalum may produce a grainy sound which I don't really want. The pedal I'm cloning from doesn't use them so I'm leary of using any substitute part types.
AFAIK, Polyester film caps are the same thing as Mylar (which is a brand name). Then there's Polypropylene, and also Polystyrene (which was used in the original wahs). So when someone says "poly film", you don't know exactly which one it is (although it probably is either polyester or polypropylene in most cases, polystyrene doesn't come up as often). I wish more people would differentiate which "poly film" cap they are talking about, as it can make a difference. I sometimes hear people say to use an "orange drop" cap, but there are different series' of Orange Drops, some are polyprop and some are polyester, and that can make a difference in some applications.
I wonder why polystyrene isn't used much in pedals and such, they used to be considered a "superior" type of cap at one time. Is it because of how they sound or because you can't find them in a lot of values?
Al
Quote from: zombiwoof on March 12, 2010, 03:14:28 PMI wonder why polystyrene isn't used much in pedals and such, they used to be considered a "superior" type of cap at one time. Is it because of how they sound or because you can't find them in a lot of values?
Expensive & large size/footprint.
Quote from: zombiwoof on March 12, 2010, 03:14:28 PM
AFAIK, Polyester film caps are the same thing as Mylar (which is a brand name).
Yes, I think you're right. Mylar Film = Polyester Film
Also, I don't believe any capacitors contribute to "noise" in a circuit.. outside of microphonics.
Metal film resistors are quieter than carbon... not capacitors.
Quote from: MmmPedals on March 12, 2010, 10:53:03 AM
Tantalum caps are a big no no in audio circuits. avoid them at all costs. they add noise and have an "unpleasant tone".
Tell that to the TS808 aficionados who believe them to be absolutely critical to the sound. :icon_twisted:
Personally I've never found anything inherently unpleasant about Tantalum and the very fact that they will last much longer than the 2000 hours specified by some electrolytic manufacturers seems a good enough reason to try them to me.
Quote from: oldschoolanalog on March 12, 2010, 03:48:32 PM
Quote from: zombiwoof on March 12, 2010, 03:14:28 PMI wonder why polystyrene isn't used much in pedals and such, they used to be considered a "superior" type of cap at one time. Is it because of how they sound or because you can't find them in a lot of values?
Expensive & large size/footprint.
I hadn't thought of that. I have been thinking about trying some polystyrene caps in one of my guitars for the tone caps, if for no other reason that I've never heard of anyone doing it (although I'm sure someone has).
I've also considered using a tantalum in place of the 4.7uf electro in a wah, I wonder if it would have any affect on the sound in that position?
As far as the tantalums in a TS808, maybe the "unpleasant" aspect of them is part of the vintage sound there. I know I've seen a lot of tantalums in Japanese pedals, even in MXR's, as I recall.
Al
This page may be useful: http://greygum.net/sbench/sbench102/caps.html (http://greygum.net/sbench/sbench102/caps.html)
It has oscilloscope traces showing how linear different capacitors are. Only a few seem to be noticeably non-linear (and would thus add distortion).
Just buck all the trends and start using monolithic ceramics :)
Any differences the crowd hears between caps will only really be in values and tolerances. Nobody else matters.
nice post. we were talking about this at work today....all the different variables that go into an electronic sound design like an amp or a pedal........my older buddy just stormed off and said "just use your fu*king ears!!!!!"
lol ;D ;D ;D
Quote from: zombiwoof on March 12, 2010, 10:41:37 PM
As far as the tantalums in a TS808, maybe the "unpleasant" aspect of them is part of the vintage sound there. I know I've seen a lot of tantalums in Japanese pedals, even in MXR's, as I recall.
I think you've come up with the most important aspect of component selection in guitar effects. What someone doesn't like in a DIY audio application may be fantastic in a comparatively lofi guitar effect. I've heard ceramic caps called gritty before but they go to make terrific Big Muffs, so maybe any grittiness they impart just works well with some dirt pedals.
Polystyrene sounds very nice in the BSIAB, in the 470pf cap (mine is a 560 pf) cap that parallels the 470k resistor.
Very clear tone.
I wonder if we should count the number of times that the question "which kind of capacitor sounds better?" or "which kind of capacitor should I use?" has appeared.
Writing it up and putting it in a FAQ doesn't seem to help.
Maybe some people just like to talk about it and exchange their opinions rather than taking an FAQ as being everything you ever need to know. That's what forums are all about.
Quote from: MmmPedals on March 12, 2010, 10:53:03 AM
Tantalum caps are a big no no in audio circuits. avoid them at all costs. they add noise and have an "unpleasant tone".
they are used in the ts 808 an ts9 plus the stratoblaster. all pretty successful designs in my opinion. plus they look cool and organic :icon_smile:
The use of tantalum caps on TS's and the Harmonic percolator has some real impact to the resulting sound, but it's not exactly where I would call it the "audio pathway" in both projects.
omg... R.G. and IvIark...
your comments on this subject are hilarious!
My face hurts from laughing.
thanks for the frank comments
and for giving so much to the DIY community.
you both have helped me out so much in the past few months
sincerely,
ben
Quote from: IvIark on March 13, 2010, 10:09:42 AM
Maybe some people just like to talk about it and exchange their opinions rather than taking an FAQ as being everything you ever need to know. That's what forums are all about.
Observation not of the quoted member, however here I was thinking it was trolling by 1 post new accounts, on tombstoned threads, concurrently to other threads on the same topic in which a low post count individual was stirring up the troubles.
Use ceramic across the board in dirt boxes, more dirt that way.
Endlessly speculating about esoteric stuff is a lot easier than e.g. learning to interpret numbers on a datasheet*, or buying test gear and learning how to use it. Dressing up speculation as fact is probably here with us to stay as well. :icon_lol:
Hint: there is more than one type of ceramic dielectric used in ceramic capacitors.
Which has the mojo though? :icon_wink:
Quote from: mistahead on August 06, 2013, 06:56:44 AM
Which has the mojo though? :icon_wink:
:icon_lol: :icon_lol: :icon_lol:
"That depends on which grade of mojo that Sir is looking for."
Quote from: R.G. on March 13, 2010, 09:24:13 AM
I wonder if we should count the number of times that the question "which kind of capacitor sounds better?" or "which kind of capacitor should I use?" has appeared.
I can't count that high
But to add my tuppence worth, for me the best capacitor to use is the one I've got. That way I can complete a project.....
Quote from: mistahead on August 06, 2013, 02:56:53 AM
Observation not of the quoted member, however here I was thinking it was trolling by 1 post new accounts, on tombstoned threads, concurrently to other threads on the same topic in which a low post count individual was stirring up the troubles.
I can only assume you are talking about me, but I have no idea what you're accusing me of. Does expressing an opinion different from yours count as 'stirring up the troubles'? What does my post count have to do with whether my arguments make any sense?
I never even try to make sense.
I have a funny feeling the search function here never turns up what the searcher is looking for. either that, or they aren't using it .........
Quote from: induction on August 06, 2013, 11:56:09 AM
Quote from: mistahead on August 06, 2013, 02:56:53 AM
Observation not of the quoted member, however here I was thinking it was trolling by 1 post new accounts, on tombstoned threads, concurrently to other threads on the same topic in which a low post count individual was stirring up the troubles.
I can only assume you are talking about me, but I have no idea what you're accusing me of. Does expressing an opinion different from yours count as 'stirring up the troubles'? What does my post count have to do with whether my arguments make any sense?
'stirring up the troubles' - little bit of tongue in cheek mate, its just the internet - sprinkle a little cement on the morning latte.
Quote from: duck_arse on August 06, 2013, 12:20:58 PM
I never even try to make sense.
I have a funny feeling the search function here never turns up what the searcher is looking for. either that, or they aren't using it .........
To be fair, the forum search function is far from foolproof.
I just typed "engineer's thumb" into the search box and it came up empty. Any fule kno that the engineer's thumb is a compressor that has it's own thread here. Searching with the keyword "thumb" seems to work though. One day computers will be as smart as the average fruitfly.
They're too smart... or in this case not forgiving enough of "human stupidity", after all we will treat ENGINEERS and ENGINEER'S the same despite their huge semantic difference.
Throw in some wildcards and a little bit "matching" logic and the search here is not too bad, use advanced and avoid using quote marks or other special characters...
I just took a break from writing some SQL in VBA to post that comment though, so maybe I'm not thebest person to ask lol.
Quote from: mistahead on August 06, 2013, 09:40:34 PM
They're too smart... or in this case not forgiving enough of "human stupidity", after all we will treat ENGINEERS and ENGINEER'S the same despite their huge semantic difference.
Throw in some wildcards and a little bit "matching" logic and the search here is not too bad, use advanced and avoid using quote marks or other special characters...
I just took a break from writing some SQL in VBA to post that comment though, so maybe I'm not thebest person to ask lol.
Computers aren't smart - they're just very good at following instructions. That said I just asked mine to make me a cup of tea and it didn't have the faintest idea what to do. Smart computers are like flying cars - promises from our childhood that ain't never gonna happen!
Did I rub you the wrong way Gritz?
There's a large number of what has been generally referred to as "Expert Systems" - this are highly intelligent in the sense that they have been able to trick humans via the Turing Test, are more effective at some forms of psychology than trained psychologists, and make independant decisions as to HOW to approach problems as well as following less prescriptive and more intuitive methodologies for applying those approaches.
They are smarter than most people - especially someone who asks their computer in a foreign language (to it) to get up and make food... :icon_wink:
Human's aren't that different - just playing out the instruction sets that someone taught you, whether or not we realise it.
Flying cars are also happening now - just outside the affordability range of most people (and limited in altitude due to licensing), thankfully, until cars are driven by expert systems I don't want to throw a whole extra dimension into the mix for the average muppet behind the wheel.
QuoteAny fule kno that the engineer's thumb is a compressor
any fule kno that the electronik brane mkVII will be superior in all aspeks, if it ever released, chiz.
I often think this shyte innernets connection has turned this laptop into a turing halting machine at the end of a run.
Quote from: gritz on August 06, 2013, 09:25:36 PM
To be fair, the forum search function is far from foolproof.
Whenever I have trouble with it I google
site:diystompboxes.com search term here. That usually works quite well.
Quote from: mistahead on August 06, 2013, 10:36:44 PM
Did I rub you the wrong way Gritz?
Heck no! Sarcasm is what passes for humour here in the UK, so maybe I didn't express myself properly. Apologies. :)
Computers have infuriated me for most of my life - I was at school when the ZX81 appeared and my response was something like "wake me up when it does something interesting". My punishment was Z80 ASM (and a bit of machine code) at college. I now use PCs extensively for creative and analysis purposes, but while their raw speed has increased by orders of magnitude, the software that runs on them tends to be as intuitive and proactive as a bag of cat turds, perhaps because the majority of people in the computer industry understand computers far better than they understand people. Folks who design phones and $5 apps tend to "get it", so why not the desktop crowd?
Any inferences that I may have made re. using "mojo" capacitors as a substitute for learning how to bias a transistor properly or buying a half decent power supply still stand too. ;)