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  #1   Report Post  
Steve Cohn
 
Posts: n/a
Default Recommend crossover capacitors, values?

I want to recap the crossovers in an old pair of high-end speakers I
own. I've opened up the cabinet and diagramed the circuit, but have a
few questions about what I found. Perhaps somebody can help.

The first thing I noticed is that many of the "better" caps (polystyrene
in this case) are run in parallel with electrolytics to reach the
desired value. I spoke with a tech who said that this was done to
achieve the filter affect of the combined capacitance while taking
advantage of the better signal path through the one quality capacitor in
the circuit. Does this make sense?

I certainly understand that there is a cost advantage of doing it this
way because the circuit uses some very high capacitance values.
Replacing these caps with modern, high-end versions would be
cost-prohibitive, if not impossible. I just want to compromise as little
quality as possible.

That leads me to the next question: how do I achieve the desired values
and maintain the quality without going broke? The midrange signal is fed
through a set of capacitors with a combined value of 75 mfd. That's much
higher than I've seen for sale from any high-end capacitor
manufacturers, and anything close is prohibitively expensive.

The next issue is with matching. I don't own a capacitance meter, so
matching the pairs myself is not an option. Is it worth buying matched
pairs of replacement caps? And what do I do if I need to add
electrolytics into the circuit to achieve the desired value? Can I buy
those matched as well?

Lastly, what are the preferred brands of capacitors to use? Are there
any good web sites that do comparisons, including listening tests?

Thanks very much in advance.

--
Steve Cohn

  #2   Report Post  
Bruno Putzeys
 
Posts: n/a
Default Recommend crossover capacitors, values?

It's unlikely that the film caps were added to increase the value of the
electrolytics appreciably. Compare the value of the film caps to the 10% (or
more) tolerance of the electrolytics. It's done in a bid to combine the
quality of the film cap with the capacitance of the electrolytic. The sound
of such parallel circuits is pretty unpredictable though - needs
experimentation when you change types of components. It's not unusual for an
electrolytic to sound better alone than with an extra film cap on top.

Intertechnik (http://www.intertechnik.de/) sells "audyn" branded film caps
up to rather large values. Very decent sounding parts.

The largest film caps are from http://www.eci-capacitors.com/. Never tried
them though.

Matching to within 10% (eg +/-5% tolerance) is desirable, to make sure the
speakers (well, ignoring differences between drive units) remain within 1dB
of eachother.

  #3   Report Post  
All Ears
 
Posts: n/a
Default Recommend crossover capacitors, values?

Here is a snip from B&Ws FAQ section, it may help....

KE

"We usually find that customers who alter crossover components are not fully
satisfied with the results. They find that some aspects are improved, but
others made worse. A classic case of this is when a polypropylene or other
very low-loss type substitutes an electrolytic capacitor. We all know that
polypropylene capacitors can sound inherently better, but the change in
internal losses changes the response of the filter, which is designed
assuming the losses of the electrolytic component. What usually happens when
the low loss component is fitted is that the corners of the roll-off are
sharpened, giving a peak in the combined response that can make the sound
unpleasant in various ways depending on the crossover frequency. One way of
getting round this is to wire a small resistor in series with the capacitor
to approximate the original losses. I say approximate because the loss
factor is a frequency dependent resistance. The actual value you need
depends on the original capacitor loss factor and its capacitance value. The
larger the value, the lower the resistance for a given loss factor. The
formula for the equivalent resistance is:
R = d / 2ðfC
where R = resistance in ohms, d = loss factor, f = frequency in Hz and C =
capacitance in farads.
Loss factor is usually expressed as a percentage at 1kHz. For a "low-loss"
electrolytic such as the values between 1µF and 20µF found in tweeter
circuits, d is of the order of 0.025 (loss factor of 2.5%). For values in
the hundreds of microfarads it may be of the order of 0.07 or 7%. Typically
therefore a good electrolytic capacitor of 5µF would have an equivalent
series resistance of 0.8?. If the capacitor has a much larger resistor in
series with it anyway, it's probably not worth altering."

"Steve Cohn" wrote in message
...
I want to recap the crossovers in an old pair of high-end speakers I
own. I've opened up the cabinet and diagramed the circuit, but have a
few questions about what I found. Perhaps somebody can help.

The first thing I noticed is that many of the "better" caps (polystyrene
in this case) are run in parallel with electrolytics to reach the
desired value. I spoke with a tech who said that this was done to
achieve the filter affect of the combined capacitance while taking
advantage of the better signal path through the one quality capacitor in
the circuit. Does this make sense?

I certainly understand that there is a cost advantage of doing it this
way because the circuit uses some very high capacitance values.
Replacing these caps with modern, high-end versions would be
cost-prohibitive, if not impossible. I just want to compromise as little
quality as possible.

That leads me to the next question: how do I achieve the desired values
and maintain the quality without going broke? The midrange signal is fed
through a set of capacitors with a combined value of 75 mfd. That's much
higher than I've seen for sale from any high-end capacitor
manufacturers, and anything close is prohibitively expensive.

The next issue is with matching. I don't own a capacitance meter, so
matching the pairs myself is not an option. Is it worth buying matched
pairs of replacement caps? And what do I do if I need to add
electrolytics into the circuit to achieve the desired value? Can I buy
those matched as well?

Lastly, what are the preferred brands of capacitors to use? Are there
any good web sites that do comparisons, including listening tests?

Thanks very much in advance.

--
Steve Cohn


  #4   Report Post  
Steve Cohn
 
Posts: n/a
Default Recommend crossover capacitors, values?

Thanks for the reply.

"Bruno Putzeys" wrote:

It's unlikely that the film caps were added to increase
the value of the electrolytics appreciably... It's done
in a bid to combine the quality of the film cap with the
capacitance of the electrolytic.


Yes, that's what I understood, though perhaps I didn't express it well.
Most of the film caps are 5 mfd. Then they're added together, or
combined with electrolytics, to reach the desired value.

It's not unusual for an electrolytic to sound better
alone than with an extra film cap on top.


Really? That's interesting. I'll have to experiment.

Intertechnik (http://www.intertechnik.de/) sells "audyn"
branded film caps up to rather large values. Very decent
sounding parts.


I don't speak enough German to navigate this site. Do you know of a US
distributor who might carry them?

Thanks again.

--
Steve Cohn

  #5   Report Post  
Steve Cohn
 
Posts: n/a
Default Recommend crossover capacitors, values?

Thanks. That was actually quite helpful.

I'd rather not mess with loss values and calculations of the resistance
needed to compensate. Sounds like my best bet is to replace the
polystyrene capacitors with some higher quality films caps of the same
value, and replace the electrolytics with the same as what's already
there. Agree?

Steve


In article ,
"All Ears" wrote:

Here is a snip from B&Ws FAQ section, it may help....
=20
KE
=20
"We usually find that customers who alter crossover components are not fu=

lly
satisfied with the results. They find that some aspects are improved, but
others made worse. A classic case of this is when a polypropylene or othe=

r
very low-loss type substitutes an electrolytic capacitor. We all know tha=

t
polypropylene capacitors can sound inherently better, but the change in
internal losses changes the response of the filter, which is designed
assuming the losses of the electrolytic component. What usually happens w=

hen
the low loss component is fitted is that the corners of the roll-off are
sharpened, giving a peak in the combined response that can make the sound
unpleasant in various ways depending on the crossover frequency. One way =

of
getting round this is to wire a small resistor in series with the capacit=

or
to approximate the original losses. I say approximate because the loss
factor is a frequency dependent resistance. The actual value you need
depends on the original capacitor loss factor and its capacitance value. =

The
larger the value, the lower the resistance for a given loss factor. The
formula for the equivalent resistance is:
R =3D d / 2=F0fC
where R =3D resistance in ohms, d =3D loss factor, f =3D frequency in Hz and C =

=3D
capacitance in farads.
Loss factor is usually expressed as a percentage at 1kHz. For a "low-loss=

"
electrolytic such as the values between 1=B5F and 20=B5F found in tweeter
circuits, d is of the order of 0.025 (loss factor of 2.5%). For values in
the hundreds of microfarads it may be of the order of 0.07 or 7%. Typical=

ly
therefore a good electrolytic capacitor of 5=B5F would have an equivalent
series resistance of 0.8?. If the capacitor has a much larger resistor in
series with it anyway, it's probably not worth altering."
=20
"Steve Cohn" wrote in message
...
I want to recap the crossovers in an old pair of high-end speakers I
own. I've opened up the cabinet and diagramed the circuit, but have a
few questions about what I found. Perhaps somebody can help.

The first thing I noticed is that many of the "better" caps (polystyren=

e
in this case) are run in parallel with electrolytics to reach the
desired value. I spoke with a tech who said that this was done to
achieve the filter affect of the combined capacitance while taking
advantage of the better signal path through the one quality capacitor i=

n
the circuit. Does this make sense?

I certainly understand that there is a cost advantage of doing it this
way because the circuit uses some very high capacitance values.
Replacing these caps with modern, high-end versions would be
cost-prohibitive, if not impossible. I just want to compromise as littl=

e
quality as possible.

That leads me to the next question: how do I achieve the desired values
and maintain the quality without going broke? The midrange signal is fe=

d
through a set of capacitors with a combined value of 75 mfd. That's muc=

h
higher than I've seen for sale from any high-end capacitor
manufacturers, and anything close is prohibitively expensive.

The next issue is with matching. I don't own a capacitance meter, so
matching the pairs myself is not an option. Is it worth buying matched
pairs of replacement caps? And what do I do if I need to add
electrolytics into the circuit to achieve the desired value? Can I buy
those matched as well?

Lastly, what are the preferred brands of capacitors to use? Are there
any good web sites that do comparisons, including listening tests?

Thanks very much in advance.

--=20
Steve Cohn


--=20
Steve Cohn



  #6   Report Post  
Mkuller
 
Posts: n/a
Default Recommend crossover capacitors, values?

Steve Cohn wrote:
I'd rather not mess with loss values and calculations of the resistance
needed to compensate. Sounds like my best bet is to replace the
polystyrene capacitors with some higher quality films caps of the same
value, and replace the electrolytics with the same as what's already
there. Agree?


While I'm no expert in this area, I can give you some information. Capacitor
quality and sound became well known to the audiophile community from a series
of articles by Marsh and Jung in Audio magazine in about 1980-81. Peter
Moncrieff of IAR took this a step further and had his Wonder Caps made to his
specs for high end equipment (Audio Research used them among others). Since
that time there have been many brands of exotic capacitors made which are used
in many high end products. One of the things Moncrieff recommended in the
early 1980s was to bypass electrolytic caps with small value polypropylene or
polystyrene, say 1/100th or 1/10th (or both using two smaller low value caps)
of the value of the larger cap. That was because larger value, high quality
caps were not available or were very expensive then. And as another poster
mentioned, by bypassing the bigger, poorer quality caps with smaller value
higher quality caps, the theory was that you get the some of the benefits
without the high cost. Sonic Frontiers (now Anthem) in Canada used to have a
subsidiary called The Parts Connection that stocked all of the exotic caps. I
believe it's gone or operating under another name now. Perhaps someone could
help you find their successor.
Regards,
Mike
  #7   Report Post  
Nousaine
 
Posts: n/a
Default Recommend crossover capacitors, values?

(Mkuller) wrote:

...snip to content .....

While I'm no expert in this area, I can give you some information. Capacitor
quality and sound became well known to the audiophile community from a series
of articles by Marsh and Jung in Audio magazine in about 1980-81. Peter
Moncrieff of IAR took this a step further and had his Wonder Caps made to his
specs for high end equipment (Audio Research used them among others).


Several years ago I conducted a controlled listening experiment where 8 mFd
WonderCaps were compared as input coupling capacitors (a commonly recommended
practice) to an assemblage of 3 Radio Shack ($0.99) electrolytic non-polar
capacitors to attain a capacitance value within 10% of the actual value of the
WonderCap as measured with a capacitance meter.

No one was able to reliably identify one from the other using the headphone
jack on the direct coupled Bryston amplifier.

Indeed in the era cited for the Jung/Marsh work I obtained high quality 10 mFd
capacitors and believed they improved the sound of an amplifier when
substituted for the original electrolytics. Until that fateful day when a
friend asked to hear "that capacitor experiment again." I happily accomodated
him but was aghast to later find I had forgotten that the "wrong" capacitor had
been re-inserted.

Yet, he reported the same improvements as before. This prompted me to repeat
this experiment with my son operating the controls and not telling me which
caps were in-circuit.

I then found that even I could not reliably tell them apart when I didn't know
beforehand which was in-circuit.
  #9   Report Post  
Steve Cohn
 
Posts: n/a
Default Recommend crossover capacitors, values?

In article ,
John Stone wrote:

If the existing film caps are polystyrenes, I wouldn't
bother replacing them at all. Polystyrenes are about as
good as it gets for crossover caps. They are very stable
and would not go bad unless the system was heavily overdriven.


Well, they look like polystyrenes, but I can't be sure. Even so, they're
20 years old. Don't they degrade over time?

Since you have no way of referencing back to the
original crossover curves, I'd do as few changes as possible.


Actually, I do have an extra set of crossovers to test, but it's true
that I don't know what the exact intentions of the designer were.

Thanks for your input. I feel like I'm getting close to a decision on
which way to take this whole project.

--
Steve Cohn

  #11   Report Post  
Joseph Oberlander
 
Posts: n/a
Default Recommend crossover capacitors, values?

Steve Cohn wrote:

In article ,
John Stone wrote:


If the existing film caps are polystyrenes, I wouldn't
bother replacing them at all. Polystyrenes are about as
good as it gets for crossover caps. They are very stable
and would not go bad unless the system was heavily overdriven.



Well, they look like polystyrenes, but I can't be sure. Even so, they're
20 years old. Don't they degrade over time?


Most definately. IMO, replacing them every 5-10 years makes a bigger
difference than osbessing over what type you use.
  #12   Report Post  
All Ears
 
Posts: n/a
Default Recommend crossover capacitors, values?

"Steve Cohn" wrote in message
...
Thanks. That was actually quite helpful.

I'd rather not mess with loss values and calculations of the resistance
needed to compensate. Sounds like my best bet is to replace the
polystyrene capacitors with some higher quality films caps of the same
value, and replace the electrolytics with the same as what's already
there. Agree?

Steve


Unless you know exactely what you are doing, and has access to proper
measuring facilities, I would not recommend fiddling too much with cross
overs. We must assume there is a reason for designing the cross over the way
it is, if cost is a part of it, we must also assume that a reasonable
compromise is done. As long as the things you do can be undone, there is no
real harm in experimenting a bit, especially if it is old speakers.

KE


  #13   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Recommend crossover capacitors, values?

On 16 Oct 2003 18:08:03 GMT, Steve Cohn
wrote:

In article ,
John Stone wrote:

If the existing film caps are polystyrenes, I wouldn't
bother replacing them at all. Polystyrenes are about as
good as it gets for crossover caps. They are very stable
and would not go bad unless the system was heavily overdriven.


Well, they look like polystyrenes, but I can't be sure. Even so, they're
20 years old. Don't they degrade over time?


Polystyrene caps have not shown any signs of degradation in the past
30 plus years.

Since you have no way of referencing back to the
original crossover curves, I'd do as few changes as possible.


Actually, I do have an extra set of crossovers to test, but it's true
that I don't know what the exact intentions of the designer were.


Well, that's the problem. As the B&W FAQ points out, their crossovers
design in the known limitations of the components employed. Change
them for 'better' components at your peril.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #14   Report Post  
Mkuller
 
Posts: n/a
Default Recommend crossover capacitors, values?

(Nousaine) wrote:
Several years ago I conducted a controlled listening experiment where 8 mFd
WonderCaps were compared as input coupling capacitors (a commonly recommended
practice) to an assemblage of 3 Radio Shack ($0.99) electrolytic non-polar
capacitors to attain a capacitance value within 10% of the actual value of
the
WonderCap as measured with a capacitance meter.

No one was able to reliably identify one from the other using the headphone
jack on the direct coupled Bryston amplifier.

Indeed in the era cited for the Jung/Marsh work I obtained high quality 10
mFd
capacitors and believed they improved the sound of an amplifier when
substituted for the original electrolytics. Until that fateful day when a
friend asked to hear "that capacitor experiment again." I happily accomodated
him but was aghast to later find I had forgotten that the "wrong" capacitor
had
been re-inserted.

Yet, he reported the same improvements as before. This prompted me to repeat
this experiment with my son operating the controls and not telling me which
caps were in-circuit.

I then found that even I could not reliably tell them apart when I didn't
know
beforehand which was in-circuit.


I have no doubt you were unable to hear capacitor differences, but many high
end equipment manufacturers listen and compare the sound of the exotic
capacitors before they decide which to put in their equipment. They tell me
they hear differences and sometimes pay extra for one brand over another
because of those differences. As an audiophile, one brand of capacitor looks
the same to me as another. The sound I hear is all that matters so don't tell
me it's just marketing.
Regards,
Mike
  #15   Report Post  
Nousaine
 
Posts: n/a
Default Recommend crossover capacitors, values?

(Mkuller) wrote:




(Nousaine) wrote:
Several years ago I conducted a controlled listening experiment where 8 mFd
WonderCaps were compared as input coupling capacitors (a commonly

recommended
practice) to an assemblage of 3 Radio Shack ($0.99) electrolytic non-polar
capacitors to attain a capacitance value within 10% of the actual value of
the
WonderCap as measured with a capacitance meter.

No one was able to reliably identify one from the other using the headphone
jack on the direct coupled Bryston amplifier.

Indeed in the era cited for the Jung/Marsh work I obtained high quality 10
mFd
capacitors and believed they improved the sound of an amplifier when
substituted for the original electrolytics. Until that fateful day when a
friend asked to hear "that capacitor experiment again." I happily

accomodated
him but was aghast to later find I had forgotten that the "wrong" capacitor
had
been re-inserted.

Yet, he reported the same improvements as before. This prompted me to repeat
this experiment with my son operating the controls and not telling me which
caps were in-circuit.

I then found that even I could not reliably tell them apart when I didn't
know
beforehand which was in-circuit.


I have no doubt you were unable to hear capacitor differences, but many high
end equipment manufacturers listen and compare the sound of the exotic
capacitors before they decide which to put in their equipment. They tell me
they hear differences and sometimes pay extra for one brand over another
because of those differences. As an audiophile, one brand of capacitor looks
the same to me as another. The sound I hear is all that matters so don't
tell
me it's just marketing.
Regards,
Mike



I'm not telling you anything except I've put these claims to the test on
several occasions and, so far, no one has been able to distinguish capacitors
by dialectric at audio frequencies in typical circuit topology under listening
bias conditions.

Walt Jung and Dick Marsh have made these claims, which I originally bought, but
neither have ever conducted a controlled test to support these beliefs.

Indeed, other than John Atkinson, I'm probably the ONLY person who has directly
compared capacitor dialectric in a straightforward manner. Although the
Atkinson liberally misinterpreted his data that experiment conclusively showed
that subjects were unable to "hear" capacitors by dialectric with regard to
sound alone.

My experiments showed this to be true as well.


  #16   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Recommend crossover capacitors, values?

On 16 Oct 2003 20:08:12 GMT, "All Ears" wrote:

"Steve Cohn" wrote in message
...
Thanks. That was actually quite helpful.

I'd rather not mess with loss values and calculations of the resistance
needed to compensate. Sounds like my best bet is to replace the
polystyrene capacitors with some higher quality films caps of the same
value, and replace the electrolytics with the same as what's already
there. Agree?

Steve


Unless you know exactely what you are doing, and has access to proper
measuring facilities, I would not recommend fiddling too much with cross
overs. We must assume there is a reason for designing the cross over the way
it is, if cost is a part of it, we must also assume that a reasonable
compromise is done. As long as the things you do can be undone, there is no
real harm in experimenting a bit, especially if it is old speakers.


This is certainly true, and B&W even include the point in their FAQ,
that crossovers are *designed* with the capacitor losses taken into
account (surprise!), so replacing with 'superior' components won't
necessarily improve the sound. BTW, you can't replace polystyrene caps
by 'higher quality' components, because polystyrene caps are the best
available.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #17   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Recommend crossover capacitors, values?

On 16 Oct 2003 20:07:42 GMT, Joseph Oberlander
wrote:

Steve Cohn wrote:

In article ,
John Stone wrote:


If the existing film caps are polystyrenes, I wouldn't
bother replacing them at all. Polystyrenes are about as
good as it gets for crossover caps. They are very stable
and would not go bad unless the system was heavily overdriven.



Well, they look like polystyrenes, but I can't be sure. Even so, they're
20 years old. Don't they degrade over time?


Most definately. IMO, replacing them every 5-10 years makes a bigger
difference than osbessing over what type you use.


For film caps, this is absolutely untrue. Anything made in the last 25
years or so has an almost indefinite lifetime, while electrolytics of
the same vintage only 'dry out' if they are in a hot environment such
as a tube amplifier.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #18   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Recommend crossover capacitors, values?

On 16 Oct 2003 23:09:29 GMT, (Mkuller) wrote:

(Nousaine) wrote:
Several years ago I conducted a controlled listening experiment where 8 mFd
WonderCaps were compared as input coupling capacitors (a commonly recommended
practice) to an assemblage of 3 Radio Shack ($0.99) electrolytic non-polar
capacitors to attain a capacitance value within 10% of the actual value of
the
WonderCap as measured with a capacitance meter.

No one was able to reliably identify one from the other using the headphone
jack on the direct coupled Bryston amplifier.

Indeed in the era cited for the Jung/Marsh work I obtained high quality 10
mFd
capacitors and believed they improved the sound of an amplifier when
substituted for the original electrolytics. Until that fateful day when a
friend asked to hear "that capacitor experiment again." I happily accomodated
him but was aghast to later find I had forgotten that the "wrong" capacitor
had
been re-inserted.

Yet, he reported the same improvements as before. This prompted me to repeat
this experiment with my son operating the controls and not telling me which
caps were in-circuit.

I then found that even I could not reliably tell them apart when I didn't
know
beforehand which was in-circuit.


I have no doubt you were unable to hear capacitor differences, but many high
end equipment manufacturers listen and compare the sound of the exotic
capacitors before they decide which to put in their equipment. They tell me
they hear differences and sometimes pay extra for one brand over another
because of those differences. As an audiophile, one brand of capacitor looks
the same to me as another. The sound I hear is all that matters so don't tell
me it's just marketing.


It's a combination of marketing, wishful thinking and very poor test
protocols on the part of those manufacturers, most of whom couldn't
design their way out of a paper bag..................

BTW, what measures do you take to eliminate bias in your 'reviews'?
--

Stewart Pinkerton | Music is Art - Audio is Engineering
  #19   Report Post  
Michael Mckelvy
 
Posts: n/a
Default Recommend crossover capacitors, values?

"Mkuller" wrote in message
...
Steve Cohn wrote:
I'd rather not mess with loss values and calculations of the resistance
needed to compensate. Sounds like my best bet is to replace the
polystyrene capacitors with some higher quality films caps of the same
value, and replace the electrolytics with the same as what's already
there. Agree?


While I'm no expert in this area, I can give you some information.

Capacitor
quality and sound became well known to the audiophile community from a

series
of articles by Marsh and Jung in Audio magazine in about 1980-81. Peter
Moncrieff of IAR took this a step further and had his Wonder Caps made to

his
specs for high end equipment (Audio Research used them among others).


Having taken to heart P.T. Barnum's words, that there's a sucker born every
minute.

Since
that time there have been many brands of exotic capacitors made which are

used
in many high end products. One of the things Moncrieff recommended in the
early 1980s was to bypass electrolytic caps with small value polypropylene

or
polystyrene, say 1/100th or 1/10th (or both using two smaller low value

caps)
of the value of the larger cap. That was because larger value, high

quality
caps were not available or were very expensive then.


This was recomended so Moncrief could sell caps.

And as another poster
mentioned, by bypassing the bigger, poorer quality caps with smaller value
higher quality caps, the theory was that you get the some of the benefits
without the high cost. Sonic Frontiers (now Anthem) in Canada used to have

a
subsidiary called The Parts Connection that stocked all of the exotic

caps. I
believe it's gone or operating under another name now. Perhaps someone

could
help you find their successor.
Regards,
Mike


Unfortunately for Moncrief, he never demonsttrated any sonic benefits from
his "Wonder" caps.

  #20   Report Post  
Joseph Oberlander
 
Posts: n/a
Default Recommend crossover capacitors, values?

Stewart Pinkerton wrote:


For film caps, this is absolutely untrue. Anything made in the last 25
years or so has an almost indefinite lifetime, while electrolytics of
the same vintage only 'dry out' if they are in a hot environment such
as a tube amplifier.


You'd be amazed at how much older equipment used electroyltics.
Oh - ozone/smog hurts them as well.


  #21   Report Post  
Stewart Pinkerton
 
Posts: n/a
Default Recommend crossover capacitors, values?

On 18 Oct 2003 00:30:21 GMT, Joseph Oberlander
wrote:

Stewart Pinkerton wrote:

For film caps, this is absolutely untrue. Anything made in the last 25
years or so has an almost indefinite lifetime, while electrolytics of
the same vintage only 'dry out' if they are in a hot environment such
as a tube amplifier.


You'd be amazed at how much older equipment used electroyltics.
Oh - ozone/smog hurts them as well.


I've been an electronics engineer for 35 years - I'm very familiar
with older equipment! Besides, you specifically stated that you change
*film* capacitors.
--

Stewart Pinkerton | Music is Art - Audio is Engineering
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