1uf tantalum v electrolytic in a klon based of pedal

Started by numpty, April 19, 2011, 08:44:00 AM

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numpty

I understand electrolytic caps can have an adverse effect on tone.
I intend to construct a klon based pedal which has 7 x 1uf caps, would 1uf 35v tantalum caps be a better substitute for the specified electrolytics in this case or are electrolytics part of the tone in fact would the be any advantage in substitution at all?

http://www.musikding.de/product_info.php/info/p1040_Tantalum-1uF.html
or
http://www.musikding.de/product_info.php/info/p213_1uF100V-radial.html

I don't think there are any voltages above 18vdc on the board.

R.G.

Quote from: numpty on April 19, 2011, 08:44:00 AM
I understand electrolytic caps can have an adverse effect on tone.
How is that, exactly? What do they change about "tone"? Highs? Lows? Mids? What?

QuoteI intend to construct a klon based pedal which has 7 x 1uf caps, would 1uf 35v tantalum caps be a better substitute for the specified electrolytics in this case or are electrolytics part of the tone in fact would the be any advantage in substitution at all?
First of all, tantalum caps **are** electrolytics; they use tantalum foil and electrolytically grown tantalum oxide instead of aluminum foil and aluminum oxide.

Before you go off chasing the mythical tone monster, do yourself a favor and find out if you can even hear the difference between an aluminum electro, a tantalum electro, and a film cap. Then ask the questions that arise out of that.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

thegnu

there are a vast array of electrolytic qualities:

http://tech.juaneda.com/en/articles/electrolyticcapacitors.html

if they're electrolytics in the design, i would just get some panasonic FCs, black gates, or elnas at mouser or digikey.  tantalums are sometimes described as being harsh or brittle sounding.  who knows.

however, looking at this schematic here:

http://www.madbeanpedals.com/projects/Sunking/docs/Sunking_ver.3.pdf

he suggests xicon high-temp electrolytics.  the caps going to ground around the 7660 are just part of the voltage double circuit (i think that's what the 7660 does).  plus, caps going to ground tend to affect your tone less.  the ones in the signal path, you can try swapping out, but if you get good quality electrolytics, i would spend more time rocking and less time angsting over parts.

actually, to be honest, i'd spend a lot of time angsting over parts. you could socket the capacitors and find out once and for all and put your mind at ease.

EDIT: but listen to R.G.

MikeH

You will hear no difference...





But your dog might.
"Sounds like a Fab Metal to me." -DougH

merlinb

For your reference, tantalum capacitors distort more than aluminium electrolytics, so are actually a  worse choice!
But as others note, I doubt you'll notice a difference.

Ice-9

There are advantages and disadvantages to using a Tant bead as opposed to a metal can aluminium electro.

Advantage = saves space
Disadvantage = cost
www.stanleyfx.co.uk

Sanity: doing the same thing over and over again and expecting the same result. Mick Taylor

Please at least have 1 forum post before sending me a PM demanding something.

familyortiz

Like RG said.
Also, neither flavor of electrolytic should be in the signal path... I would only use these in the power supply or for decoupling (noise filtering). If anywhere else, they'd be used for ac coupling but I still prefer non polarized caps for this.

ddpawel


numpty

Hi
Thanks for you replies and opinions, I think you have confirmed my suspicions that the difference would be indiscernible. I will use xicons as mkt film caps are to big.

"How is that, exactly? What do they change about "tone"? Highs? Lows? Mids? What?"
- BTW here is a very long article about electrolytics: http://sound.westhost.com/articles/capacitors.htm If anybody is interested!

There is on thing though, don't electrolytics deteriorate after a time?

familyortiz

For amplifiers, many say a good rule of thumb is change them out every 15 years or so, since they tend to dry out but in a low power application they should last a lot longer.

caress

Quote from: numpty on April 20, 2011, 05:51:08 AM
- BTW here is a very long article about electrolytics: http://sound.westhost.com/articles/capacitors.htm If anybody is interested!

this is my favorite line in that article:
"Perform all the blind tests you can with capacitors used in real circuits. Having done this, if you still think there is a difference (and can demonstrate it to others in a blind test), then you will probably be the first to do so."   ;D

zombiwoof

I've always wondered if tantalums have a longer lifespan than electros in a pedal.   I've heard of electros going bad after 20+ years in pedals, is it the same with tantalums?.   I was thinking about it because I noticed that in some Thomas-era CryBaby's they used a tantalum instead of an electro for the 4.0uf cap (4.7uf in today's wahs), I don't know if this would have any effect on the sound but would the tant last longer?.

Not really a big deal, but what do you think?.

Al

Projectile

I don't want to get into any kind of debate about the particular merits of different caps, but it doesn't really matter anyway, since there are plenty of poly-film caps available in 1uF. There's really no need to use polarized caps for 1uF unless you are trying to save space. Poly film all the way.

Mark Hammer

1) I always find it amusing when people talk about "an adverse effect on tone" when in reality they are discussing something intended to generate distortion.  If we were talking about a sound system intended to reproduce pristine sound in a pristine manner, THEN you can drive yourself crazy about caps.  But this is rock and roll, baby, and the Klon Centaur is designed to push an amp over the edge.

2) I've had two ungooped Klons in my hands, such that I could clearly see the parts.  And I know two things about Bill Finnegan: a) he is VERY particular about components, and b) he is not an engineer, but "designs" by the seat of his pants in a very empirical manner.  That is, he tries out components, and goes with what his ears dictate.  One of the boards he sent me to work with had every single component socketed such that he could easily take a part out, stick another in and listen to the sonic change.  So if the original doesn't use tantalum, there is likely an empirical, rather than theoretical reason behind it.  I'm not saying his sonic tastes are yours or better than yours, but there are an awful lot of players we all admire who like Bill's sonic tastes a LOT.

3) The Klon is not supposed to have a sound of its own.  Used as a distortion pedal (i.e., for its own sound), it is not very good, and a regular source of disappointment to those who bought one for too much money on e-bay, thinking it would sound fabulous in spite of everything else.  Its designed intent is to push an already likeable amp in a particular way such that the amp itself provides great overdrive.  If that is not your intent, then I suggest you stop driving yourself nuts and opt for another project instead.  If Bill/Klon was still in business, and taking phone calls, he would probably have given you the same advice.

Govmnt_Lacky

Quote from: Mark Hammer on April 26, 2011, 09:57:42 AM
...If Bill/Klon was still in business, and taking phone calls, he would probably have given you the same advice.

:-X
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

Mark Hammer

For all I know he may still be talking to pedal owners, though if he has no current product to sell he is probably not looking to spend hours each day telling people that.

zombiwoof

Any experts out there have an answer to my question about tant vs. electro that I posted above?.

Al

R.G.

Quote from: zombiwoof on April 26, 2011, 12:51:05 AM
I've always wondered if tantalums have a longer lifespan than electros in a pedal.   I've heard of electros going bad after 20+ years in pedals, is it the same with tantalums?.   I was thinking about it because I noticed that in some Thomas-era CryBaby's they used a tantalum instead of an electro for the 4.0uf cap (4.7uf in today's wahs), I don't know if this would have any effect on the sound but would the tant last longer?.
Tantalums ARE electrolytics - they use tantalum oxide films instead of aluminum oxide films for insulation.

From Engineer's Edge:
Quotetantalum capacitors are highly reliable - electrical performance qualities do not degrade over time. Tantalum capacitors do not lose capacitance unlike electrolytic capacitors - in fact, the shelf life for tantalums is regarded as unlimited. Fourth, tantalum capacitors don't wear out - in fact, if there is an imperfection in the dielectric layer of a tantalum, the resistance of the manganese dioxide layer will typically convert to a form that is even more resistive. The new oxide form plugs up the faulty region and results in a reduction in current flow.
Which would seem to say "don't use anything but tantalum!" right? Well, they're hugely expensive, and as noted in wikipedia:

QuoteCompared to aluminum electrolytics, tantalum capacitors have very stable capacitance, little DC leakage, and very low impedance at high frequencies. However, unlike aluminum electrolytics, they are intolerant of positive or negative voltage spikes and are destroyed (often exploding violently) if connected in the circuit backwards or exposed to spikes above their voltage rating...

When I was a green-eared engineerling designing power supplies, one day our bosses told us "Don't use tanalum caps in anything any more. Corporate directive." Seems that there had been a particularly ugly tantalum failure in a logic board in a multimillion dollar computer installation that resulted in a nasty lawsuit, and ... well, you see where that is going.

From the techie side, tantalum has some advantages. IMHO, they're too fragile and expensive not to just go use film caps instead. Want long lifespan, use film.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

StereoKills

Tantalum caps WILL violently explode if you get voltage spikes or reverse the polarity. This one let out a particularly large plume of magic smoke in my face a while back.....

"Sometimes it takes a thousand notes to make one sound"

zombiwoof

Quote from: R.G. on April 27, 2011, 12:27:39 AM
Quote from: zombiwoof on April 26, 2011, 12:51:05 AM
I've always wondered if tantalums have a longer lifespan than electros in a pedal.   I've heard of electros going bad after 20+ years in pedals, is it the same with tantalums?.   I was thinking about it because I noticed that in some Thomas-era CryBaby's they used a tantalum instead of an electro for the 4.0uf cap (4.7uf in today's wahs), I don't know if this would have any effect on the sound but would the tant last longer?.
Tantalums ARE electrolytics - they use tantalum oxide films instead of aluminum oxide films for insulation.

From Engineer's Edge:
Quotetantalum capacitors are highly reliable - electrical performance qualities do not degrade over time. Tantalum capacitors do not lose capacitance unlike electrolytic capacitors - in fact, the shelf life for tantalums is regarded as unlimited. Fourth, tantalum capacitors don't wear out - in fact, if there is an imperfection in the dielectric layer of a tantalum, the resistance of the manganese dioxide layer will typically convert to a form that is even more resistive. The new oxide form plugs up the faulty region and results in a reduction in current flow.
Which would seem to say "don't use anything but tantalum!" right? Well, they're hugely expensive, and as noted in wikipedia:

QuoteCompared to aluminum electrolytics, tantalum capacitors have very stable capacitance, little DC leakage, and very low impedance at high frequencies. However, unlike aluminum electrolytics, they are intolerant of positive or negative voltage spikes and are destroyed (often exploding violently) if connected in the circuit backwards or exposed to spikes above their voltage rating...

When I was a green-eared engineerling designing power supplies, one day our bosses told us "Don't use tanalum caps in anything any more. Corporate directive." Seems that there had been a particularly ugly tantalum failure in a logic board in a multimillion dollar computer installation that resulted in a nasty lawsuit, and ... well, you see where that is going.

From the techie side, tantalum has some advantages. IMHO, they're too fragile and expensive not to just go use film caps instead. Want long lifespan, use film.

Thanks, I just wondered why in some Thomas-era wahs they used tants instead of "regular" electros for the 4.0/4.7uf cap that almost all wahs use.  It seems they only used them in some, but I've seen a couple of wahs from that era with them.   And yes, I know about the "exploding" think that another poster mentioned, it's been noted here a few times on the forum.  As I said, I wondered if they had a longer lifespan than electros, from your post I'm assuming the answer is "no".   Just something I've wondered for some time, thanks for clearing it up.   I've also seen tants and electros used interchageably in different eras of other commercial pedals, like DOD, etc..

That 4.0/4.7uf electro used in wahs was originally spec'd as non-polar (that's what was in the vintage Vox/Crybaby pedals), but in modern wahs they always seem to use polar caps for that one.  There are 4.7uf non-polar mini-electros available as modern production (I think Xicon makes them, I've seen them at Mouser), I assume the reason modern wah-makers use polar ones is that they might cost a penny less than the non-polar version.   It would be nice to find a small 4.0uf film cap to use instead, but I've never found one that is small enough for commercial wah boards.

Al