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Does capacitor type matter in a passive circuit

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Anonymous
July 15, 2005 7:34:29 PM

Archived from groups: rec.audio.tech (More info?)

It's for a guitar tone control and I'd like to replace the little 0.1mF
marked 104 light dull brown about 3/8" circular cap with a paper in oil
which I happen to have or a hovland or something of a bit more quality.
Would there be any loss of signal using a different type of capacitor
or is a cap a cap and all that matters is the rating and that the volate
meets or exceeds the requirement?
Anonymous
July 15, 2005 7:34:30 PM

Archived from groups: rec.audio.tech (More info?)

"ebyea" wrote ...
> It's for a guitar tone control and I'd like to replace the little 0.1mF
> marked 104 light dull brown about 3/8" circular cap with a paper in oil
> which I happen to have or a hovland or something of a bit more quality.
> Would there be any loss of signal using a different type of capacitor or
> is a cap a cap and all that matters is the rating and that the volate
> meets or exceeds the requirement?

IMHO, the question is NOT passive vs. active.
The question is whether it is in the signal path or not?

Few people care about transient intermodulation distotion
of a power filter capacitor, for example.

In your case, this is clearly a signal path component.
OTOH, the effort of replacing what is already there
may very well be not worth any potential result.
Anonymous
July 15, 2005 7:37:47 PM

Archived from groups: rec.audio.tech (More info?)

Bob Pease at NatSemi says it's all hooey and they are all the same. My
ears say slightly different, but the currently popular types made by
regular electronic sources are okay so special tweak components are
not needed.
Related resources
Anonymous
July 15, 2005 7:38:06 PM

Archived from groups: rec.audio.tech (More info?)

"ebyea" <ebyea@aol.spam.com> wrote in message
news:hdUBe.5428$2c7.801@fe11.lga

> It's for a guitar tone control and I'd like to replace the
> little 0.1mF marked 104 light dull brown about 3/8"
circular
> cap with a paper in oil which I happen to have or a
hovland or
> something of a bit more quality.

This sounds like a pretty typical part for this kind of
application.

Need practice soldering?

>Would there be any loss of
> signal using a different type of capacitor or is a cap a
cap
> and all that matters is the rating and that the volate
meets
> or exceeds the requirement?

If the origional cap was suitable for the application, which
it sounds like, and the cap is in a good state of repair,
then changing it is just soldering practice.
Anonymous
July 15, 2005 10:42:12 PM

Archived from groups: rec.audio.tech (More info?)

This is a small cap that is connected to probably a linear taper 300K ohm
pot that allows a variable amount of the signal from the magnetic pickup to
shunt to ground through this capacitor. It bleeds the treble off of the
signal. Usually ceramic disks are used for this, but tantalum dip drops are
good too. Magnetic guitar pickups put out a surprising voltage, but there
isn't much current there. I still remember the Koss Pro4X headphone
phenomenon though... Those phones are sensitive enough to hear the guitar
signal straight from the pickup with no amp at all. But yes... I would call
this a classic case of a "passive" filter cap.

I used to do a lot of guitar hot-rodding.

~James. :o )

"ebyea" <ebyea@aol.spam.com> wrote in message
news:hdUBe.5428$2c7.801@fe11.lga...
> It's for a guitar tone control and I'd like to replace the little 0.1mF
> marked 104 light dull brown about 3/8" circular cap with a paper in oil
> which I happen to have or a hovland or something of a bit more quality.
> Would there be any loss of signal using a different type of capacitor
> or is a cap a cap and all that matters is the rating and that the volate
> meets or exceeds the requirement?
Anonymous
July 15, 2005 11:29:59 PM

Archived from groups: rec.audio.tech (More info?)

James Lehman wrote:
> This is a small cap that is connected to probably a linear taper 300K ohm
> pot that allows a variable amount of the signal from the magnetic pickup to
> shunt to ground through this capacitor. It bleeds the treble off of the
> signal. Usually ceramic disks are used for this, but tantalum dip drops are
> good too. Magnetic guitar pickups put out a surprising voltage, but there
> isn't much current there. I still remember the Koss Pro4X headphone
> phenomenon though... Those phones are sensitive enough to hear the guitar
> signal straight from the pickup with no amp at all. But yes... I would call
> this a classic case of a "passive" filter cap.
>
> I used to do a lot of guitar hot-rodding.
>
> ~James. :o )
>
> "ebyea" <ebyea@aol.spam.com> wrote in message
> news:hdUBe.5428$2c7.801@fe11.lga...
>
>>It's for a guitar tone control and I'd like to replace the little 0.1mF
>>marked 104 light dull brown about 3/8" circular cap with a paper in oil
>>which I happen to have or a hovland or something of a bit more quality.
>> Would there be any loss of signal using a different type of capacitor
>>or is a cap a cap and all that matters is the rating and that the volate
>>meets or exceeds the requirement?
>
>
>
Would ceramic disk replaced by tantalum dip drops be better?
July 16, 2005 12:49:45 AM

Archived from groups: rec.audio.tech (More info?)

In article <hdUBe.5428$2c7.801@fe11.lga>, ebyea <ebyea@aol.spam.com> wrote:
>It's for a guitar tone control and I'd like to replace the little 0.1mF
>marked 104 light dull brown about 3/8" circular cap with a paper in oil
>which I happen to have or a hovland or something of a bit more quality.
> Would there be any loss of signal using a different type of capacitor
>or is a cap a cap and all that matters is the rating and that the volate
>meets or exceeds the requirement?

Passive, a very loose word. There has to be some electrical activity in there.
Is this a tube amp? An external line stage? There is voltage rating to
contend with. Different caps can have different effects, but those effects
are also dependent on the circuit.

greg
Anonymous
July 16, 2005 2:36:48 AM

Archived from groups: rec.audio.tech (More info?)

The value is not in the sound but the originality of the part as a
1957 Gibson Les Paul Standard is now "worth" a six figure sum. It's
idiotic, but so are Stradivarius violins, Ferraris, Purdey shotguns,
and Marilyn Monroe's phone book. (Especially the phone book-everyone in
it is now dead!)
Anonymous
July 16, 2005 6:23:23 AM

Archived from groups: rec.audio.tech (More info?)

On Fri, 15 Jul 2005 15:34:29 -0400, ebyea <ebyea@aol.spam.com> wrote:

>It's for a guitar tone control and I'd like to replace the little 0.1mF
>marked 104 light dull brown about 3/8" circular cap

This description sounds like a ceramic disk, and that's what I
recall seeing in (insert any name brand here) electric guitars.

>with a paper in oil
>which I happen to have or a hovland or something of a bit more quality.
> Would there be any loss of signal using a different type of capacitor
>or is a cap a cap and all that matters is the rating and that the volate
>meets or exceeds the requirement?

Capacitor needs do vary with application, but 'passive circuit' is
too general of a description to make a determination. While a ceramic
is generally considered a 'bad' cap (it's probably microphonic - if
you tap on it, you may hear the 'tap' through the electrical output of
the guitar, and unless it's marked np0, capacitance will change with
temperature), it's good enough for a tone control inside a guitar.
Actually, I might consider replacing it with something that's not
microphonic, but even then it seems unlikely to cause a problem. I
wouldn't bother unless I had the electronics open for some other
reason.

I've seen something like "Original tone control capacitor from 1957
Les Paul" on ebay, as if the exact capacitor had some special part of
the sound. I'd be very surprised if anyone could hear a difference
between it and any other capacitor of the same value.

-----
http://www.mindspring.com/~benbradley
Anonymous
July 16, 2005 10:36:58 AM

Archived from groups: rec.audio.tech (More info?)

On Fri, 15 Jul 2005 20:49:45 GMT, szekeres@pitt.edu (GregS) wrote:

>In article <hdUBe.5428$2c7.801@fe11.lga>, ebyea <ebyea@aol.spam.com> wrote:
>>It's for a guitar tone control and I'd like to replace the little 0.1mF
>>marked 104 light dull brown about 3/8" circular cap with a paper in oil
>>which I happen to have or a hovland or something of a bit more quality.
>> Would there be any loss of signal using a different type of capacitor
>>or is a cap a cap and all that matters is the rating and that the volate
>>meets or exceeds the requirement?
>
>Passive, a very loose word. There has to be some electrical activity in there.
>Is this a tube amp? An external line stage? There is voltage rating to
>contend with. Different caps can have different effects, but those effects
>are also dependent on the circuit.

Can you not read? It's part of an electric guitar.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
Anonymous
July 16, 2005 10:39:36 AM

Archived from groups: rec.audio.tech (More info?)

On 15 Jul 2005 22:36:48 -0700, calcerise@hotmail.com wrote:

> The value is not in the sound but the originality of the part as a
>1957 Gibson Les Paul Standard is now "worth" a six figure sum. It's
>idiotic, but so are Stradivarius violins, Ferraris, Purdey shotguns,
>and Marilyn Monroe's phone book. (Especially the phone book-everyone in
>it is now dead!)

Excuse me? What's 'idiotic' about a Ferrari, or a pair of Purdeys? Or
indeed the distinctive sound of Stradivari?

--

Stewart Pinkerton | Music is Art - Audio is Engineering
Anonymous
July 16, 2005 6:37:06 PM

Archived from groups: rec.audio.tech (More info?)

If you want to record a guitar straight in to a board you want an
impedance matching transformer, or a buffer amp, located at the guitar
end of the cable. Essentially it will sound like an old Les Paul
record, because that is what he did.
Anonymous
July 16, 2005 6:43:18 PM

Archived from groups: rec.audio.tech (More info?)

The prices are what is especially idiotic-the old Ferraris had Cinzano
wrappers for fuses and were painted with mops, Purdey never built a
double gun with the strength or true precision of numerous American
guns, and the distinctive sound of Stradivari hasn't ben heard as
Stradivari did in almost 200 years-ALL old violins of any quality from
that era have been substantially reworked for modern playing.

Gratification is art. Realization is engineering plus
craftsmanship-and the doing is the real satisfaction. Not seeing whose
dick is the biggest via the second rate means of Sotheby's.
Anonymous
July 16, 2005 8:24:56 PM

Archived from groups: rec.audio.tech (More info?)

Another thing I'd like to add to this thread is the importance of a shunt
resister to ground, near the pickup. I've done a lot of recording and tried
all sorts of things to get different sounds out of a variety of musical
instruments. If you think that having nothing at all between your pickup and
amp is a good idea... Well, consider this: a guitar pickup is a coil. It has
inductive reactance. This is the number one reason why guitar amp inputs are
usually very high impendence, like 100K ohms or more. Typical stereo
equipment inputs are 50K ohms or less. That's why a clean guitar signal into
a tape deck input sounds very fat and dull. Also note that a guitar amp is
not designed to make ordinary music program sound good. It is designed to
make a single guitar sound good and that might mean all sorts of bizarre
variations on the frequency response, via passive and active filters, tone
controls and clipping... Nothing to do with high fidelity! Back to the
point... If you want to use a naked pickup right into an amp, at least put a
250K ohm resister across it; right on the leads of the pickup itself. The
guitar cord you are using will have capacitance in it that might otherwise
create a very resonant system with the pickup coil. This can have the effect
of creating a HUGE peak in the extreme high end that can really be a pain
with the way it effects signal levels and direct recording.

~James. :o )

"ebyea" <ebyea@aol.spam.com> wrote in message
news:hdUBe.5428$2c7.801@fe11.lga...
> It's for a guitar tone control and I'd like to replace the little 0.1mF
> marked 104 light dull brown about 3/8" circular cap with a paper in oil
> which I happen to have or a hovland or something of a bit more quality.
> Would there be any loss of signal using a different type of capacitor
> or is a cap a cap and all that matters is the rating and that the volate
> meets or exceeds the requirement?
Anonymous
July 16, 2005 8:52:08 PM

Archived from groups: rec.audio.tech (More info?)

> I've seen something like "Original tone control capacitor from 1957
> Les Paul" on ebay, as if the exact capacitor had some special part of
> the sound. I'd be very surprised if anyone could hear a difference
> between it and any other capacitor of the same value.

Maybe he's replacing it so he can make some dough? He'll replace it with
a 99 cent radio shack job and then make a killing off ebay selling the
"original tone control capacitor from 1957 Les Paul".
Anonymous
July 16, 2005 8:52:09 PM

Archived from groups: rec.audio.tech (More info?)

MZ wrote:
>
>> I've seen something like "Original tone control capacitor from 1957
>>Les Paul" on ebay, as if the exact capacitor had some special part of
>>the sound. I'd be very surprised if anyone could hear a difference
>>between it and any other capacitor of the same value.
>
>
> Maybe he's replacing it so he can make some dough? He'll replace it with
> a 99 cent radio shack job and then make a killing off ebay selling the
> "original tone control capacitor from 1957 Les Paul".
No it's a 97 strat and I've had it with passive pickups. So I bought a
pair of emg that are powered by a 9 volt battery. Since I'm wiring the
whole thing from scratch now I figured why put the cheap ceramic in
there. Out of all the posts with the usual snipes and chatter there was
one useful suggestion of using a tantalum dipped but alas in 0.1mF Rat
Shack only has metallized so I'm still at the start>

Can I use metallized (is that just another name for tantalum dipped?)
can I put a tin foil in there I have several I use for speaker crossover
bypass on tweeter caps (another whole lifetime of threads in this ng as
to why toilet paper and clothes hangers are just as good as high quality
caps and wire).

Thanks.
Anonymous
July 16, 2005 11:30:06 PM

Archived from groups: rec.audio.tech (More info?)

>No it's a 97 strat and I've had it with passive pickups. So I bought a
>pair of emg that are powered by a 9 volt battery. Since I'm wiring the
>whole thing from scratch now I figured why put the cheap ceramic in
>there. Out of all the posts with the usual snipes and chatter there was
>one useful suggestion of using a tantalum dipped but alas in 0.1mF Rat
>Shack only has metallized so I'm still at the start>
>
>Can I use metallized (is that just another name for tantalum dipped?)

"Metallized" almost certainly refers to a metallized plastic film
(likely mylar) cap. These are similar in many respects to a foil-and-
plastic-film cap, but the conductive elements in the cap consist of a
thin layer of metal vaccum-deposited on the plastic film, rather than
a separate layer of metal foil. They're smaller and less expensive
than foil-and-film caps of similar capacitance and voltage rating.

For audio signal-coupling purposes, metallized-film caps are usually
quite good. Their behavior is closer to that of an "ideal" capacitance
than a dipped tantalum cap (which is an electrically-polarized design
and often not a good choice in an AC signal coupling application), or
most types of ceramic cap.

Tantalum dipped caps usually don't come in sizes as small as .1 uF.

So, sure, if you want clean signal coupling, use a .1 uf
metallized-film cap.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Anonymous
July 16, 2005 11:30:07 PM

Archived from groups: rec.audio.tech (More info?)

Dave Platt wrote:
>>No it's a 97 strat and I've had it with passive pickups. So I bought a
>>pair of emg that are powered by a 9 volt battery. Since I'm wiring the
>>whole thing from scratch now I figured why put the cheap ceramic in
>>there. Out of all the posts with the usual snipes and chatter there was
>>one useful suggestion of using a tantalum dipped but alas in 0.1mF Rat
>>Shack only has metallized so I'm still at the start>
>>
>>Can I use metallized (is that just another name for tantalum dipped?)
>
>
> "Metallized" almost certainly refers to a metallized plastic film
> (likely mylar) cap. These are similar in many respects to a foil-and-
> plastic-film cap, but the conductive elements in the cap consist of a
> thin layer of metal vaccum-deposited on the plastic film, rather than
> a separate layer of metal foil. They're smaller and less expensive
> than foil-and-film caps of similar capacitance and voltage rating.
>
> For audio signal-coupling purposes, metallized-film caps are usually
> quite good. Their behavior is closer to that of an "ideal" capacitance
> than a dipped tantalum cap (which is an electrically-polarized design
> and often not a good choice in an AC signal coupling application), or
> most types of ceramic cap.
>
> Tantalum dipped caps usually don't come in sizes as small as .1 uF.
>
> So, sure, if you want clean signal coupling, use a .1 uf
> metallized-film cap.
>
Beautifully said, thanks for the info.
Anonymous
July 17, 2005 12:10:34 AM

Archived from groups: rec.audio.tech (More info?)

ebyea <ebyea@aol.spam.com> wrote:
>
>No it's a 97 strat and I've had it with passive pickups. So I bought a
>pair of emg that are powered by a 9 volt battery. Since I'm wiring the
>whole thing from scratch now I figured why put the cheap ceramic in there.

Why have a tone control cap in there at all? Every guitar player I knew
invariably kept the control wide open anyway.

Just for kicks & grins I disconnected the whole tone circuit from a
friend's axe; the sound was a tad brighter and louder, I recall, but
he eventually got nervous about resale and wanted it back to stock.


Francois.
Anonymous
July 17, 2005 2:49:44 AM

Archived from groups: rec.audio.tech (More info?)

On Sat, 16 Jul 2005 14:41:56 -0400, ebyea <ebyea@aol.spam.com> wrote:

>MZ wrote:
>>
>>> I've seen something like "Original tone control capacitor from 1957
>>>Les Paul" on ebay, as if the exact capacitor had some special part of
>>>the sound. I'd be very surprised if anyone could hear a difference
>>>between it and any other capacitor of the same value.
>>
>>
>> Maybe he's replacing it so he can make some dough? He'll replace it with
>> a 99 cent radio shack job and then make a killing off ebay selling the
>> "original tone control capacitor from 1957 Les Paul".
>No it's a 97 strat and I've had it with passive pickups. So I bought a
>pair of emg that are powered by a 9 volt battery. Since I'm wiring the
>whole thing from scratch now I figured why put the cheap ceramic in
>there.

What model are these pickups? One of the (usually desirable)
characteristics of guitar pickups is the coil's self-resonance around
7kHz. I must admit I'm not familiar with the sound (or internal
impedance levels before amplification, etc.) of active pickups.

>Out of all the posts with the usual snipes and chatter there was
>one useful suggestion of using a tantalum dipped but alas in 0.1mF Rat
>Shack only has metallized so I'm still at the start>

A tantalum is a polarized capacitor like an (aluminum)
electrolytic, I saw that but I don't understand why anyone would have
suggested it.

>Can I use metallized (is that just another name for tantalum dipped?)

Yes you can, no it's not - a "metallized" is made from a thin
plastic sheet with a metal coated on each side, then rolled up.

>can I put a tin foil in there I have several I use for speaker crossover
>bypass on tweeter caps

Yes, actually most any type of capacitor (other than electrolytic,
either aluminim or tantalum) with the correct capacitance will be
better than a ceramic for this application.

>(another whole lifetime of threads in this ng as
>to why toilet paper and clothes hangers are just as good as high quality
>caps and wire).
>
>Thanks.

-----
http://www.mindspring.com/~benbradley
Anonymous
July 17, 2005 2:49:45 AM

Archived from groups: rec.audio.tech (More info?)

Ben Bradley wrote:
> On Sat, 16 Jul 2005 14:41:56 -0400, ebyea <ebyea@aol.spam.com> wrote:
>
>
>>MZ wrote:
>>
>>>> I've seen something like "Original tone control capacitor from 1957
>>>>Les Paul" on ebay, as if the exact capacitor had some special part of
>>>>the sound. I'd be very surprised if anyone could hear a difference
>>>>between it and any other capacitor of the same value.
>>>
>>>
>>>Maybe he's replacing it so he can make some dough? He'll replace it with
>>>a 99 cent radio shack job and then make a killing off ebay selling the
>>>"original tone control capacitor from 1957 Les Paul".
>>
>>No it's a 97 strat and I've had it with passive pickups. So I bought a
>>pair of emg that are powered by a 9 volt battery. Since I'm wiring the
>>whole thing from scratch now I figured why put the cheap ceramic in
>>there.
>
>
> What model are these pickups? One of the (usually desirable)
> characteristics of guitar pickups is the coil's self-resonance around
> 7kHz. I must admit I'm not familiar with the sound (or internal
> impedance levels before amplification, etc.) of active pickups.
>
>
>>Out of all the posts with the usual snipes and chatter there was
>>one useful suggestion of using a tantalum dipped but alas in 0.1mF Rat
>>Shack only has metallized so I'm still at the start>
>
>
> A tantalum is a polarized capacitor like an (aluminum)
> electrolytic, I saw that but I don't understand why anyone would have
> suggested it.
>
>
>>Can I use metallized (is that just another name for tantalum dipped?)
>
>
> Yes you can, no it's not - a "metallized" is made from a thin
> plastic sheet with a metal coated on each side, then rolled up.
>
>
>>can I put a tin foil in there I have several I use for speaker crossover
>>bypass on tweeter caps
>
>
> Yes, actually most any type of capacitor (other than electrolytic,
> either aluminim or tantalum) with the correct capacitance will be
> better than a ceramic for this application.
>
>
>>(another whole lifetime of threads in this ng as
>>to why toilet paper and clothes hangers are just as good as high quality
>>caps and wire).
>>
>>Thanks.
>
>
> -----
> http://www.mindspring.com/~benbradley
http://www.emgpickups.com/company.asp
!