Audiophile grade capacitors- a tubes only affectation?

[tube fanatic]

No discussion of tube amps is complete without including the issue of the so called "audiophile grade" capacitors and attributing sonic qualities to exotic dielectric materials such as bees wax.  This leads to an obvious question (at least to me):  Why is it that discussions about "audiophile grade" capacitors are always in the context of their use in tube type equipment?  Solid state gear uses far more of them, yet I never see discussions about replacing all signal path caps as a means of greatly improving the sound.  Granted, doing pcb rework is a much more difficult task for those without experience, but it can still be done with care and patience.  My views on such caps are well known, and I tend to agree with the premises stated in this excellent paper by Rod Elliott:

 

http://sound.westhost.com/articles/capacitors.htm

 

If anyone has done blind listening tests with tube or ss equipment in which different grades of caps were swapped in and out, with sonic differences being consistently identified, I'm anxious to learn of your results.  I'm not looking to start an ongoing argument as I consider all points of view to be as valid as my own.  Just curious as my own experiments in that area, with very closely matched capacitor values, did not yield any identifiable differences.

 

Maynard
 

[Lemon string]

I've found a few pretty cool blogs where the poster has listed a series of caps that they had compared. In all cases I found them to be interesting and informative. In most cases that I have found the caps were being switched out in the speakers crossovers but I believe I have stumbled on to one or two where the caps were being used with in a amp.

 

I just had my amp serviced and had the caps replaced, due to age, with nichicon golds. I wasn't able to a-b the difference however.

[Schu]

i see hot rodded SS amp's all the time. I think that maybe it more associated with tubes than solid state is because tube amp scene is more hobbyist saturated... who knows.

[Guest thesloth]

 

 

Honestly I think the fact that tubes are high impedance devices means that for the same time constant (RC) you need a much smaller capacitance so you have much more choices to pick from as far as dielectric composition goes. Smaller caps means better quality ones are cheaper. Ever see the size of a 10uF film cap compared to a 10uF electrolytic cap of the same voltage rating? HUGE size and price difference!!!!!!!!!!!!!!!!!!!

Edited August 6, 2015 by thesloth

[Guest thesloth]

I guess nobody else has anything to say on the matter?

 

 

I was just floored to find in the garage sale section someone selling capacitors for $80ea. This is crazy!

 

People that claim they hear a difference are not taking into consideration tolerance and a bunch of other variables. For example a capacitor that has 10% tolerance in a circuit is then swapped out for another brand which we will say has the same tolerance of 10%. The value capacitor lets say is .47uF. The original cap lets say was 10% low so is actually .42uF and the new cap is 10% higher so is actually .52uF.  Lets do some math. Let's say this is a coupling capacitor and the input impedance of the next stage is 10k. The capacitor and input impedance create a first order high pass filter. With the original cap's actual value (.42uF) the 3db roll off is @ 38Hz. The new upgraded cap's actual value is  .52uF and lowers the 3db rolloff to 30Hz. Not to mention ESR and all the other variables that could possibly attribute a noticeable sonic difference. Someone not taking notes of these small differences will just attribute the better bass to this new magical capacitor made of special imported snake oil.

 

I quote Rod in that article posted above for those who didn't read it.

 

"One thing you can count on ... if anyone wants to sell you 'special' capacitors, designed to replace 'inferior' types (such as polyester, PET, Mylar^®, etc.), then you know that there is a problem. These vendors are cashing in on the audio snake-oil bandwagon. Like cables, many of their offerings are likely to be of good quality, but at many times the genuine value of the part. Others will be perfectly ordinary parts that have been re-badged. For example, there are many capacitors sold as polypropylene that are actually PET or Mylar. It seems that no-one has ever heard the difference, simply believing that it is polypropylene, so therefore sounds 'better'."

Edited August 7, 2015 by thesloth

[Max2]

I guess nobody else has anything to say on the matter?

 

 

I was just floored to find in the garage sale section someone selling capacitors for $80ea. This is crazy!

 

People that claim they hear a difference are not taking into consideration tolerance and a bunch of other variables. For example a capacitor that has 10% tolerance in a circuit is then swapped out for another brand which we will say has the same tolerance of 10%. The value capacitor lets say is .47uF. The original cap lets say was 10% low so is actually .42uF and the new cap is 10% higher so is actually .52uF.  Lets do some math. Let's say this is a coupling capacitor and the input impedance of the next stage is 10k. The capacitor and input impedance create a first order high pass filter. With the original cap's actual value (.42uF) the 3db roll off is @ 38Hz. The new upgraded cap's actual value is  .52uF and lowers the 3db rolloff to 30Hz. Not to mention ESR and all the other variables that could possibly attribute a noticeable sonic difference. Someone not taking notes of these small differences will just attribute the better bass to this new magical capacitor made of special imported snake oil.

 

I quote Rod in that article posted above for those who didn't read it.

 

"One thing you can count on ... if anyone wants to sell you 'special' capacitors, designed to replace 'inferior' types (such as polyester, PET, Mylar^®, etc.), then you know that there is a problem. These vendors are cashing in on the audio snake-oil bandwagon. Like cables, many of their offerings are likely to be of good quality, but at many times the genuine value of the part. Others will be perfectly ordinary parts that have been re-badged. For example, there are many capacitors sold as polypropylene that are actually PET or Mylar. It seems that no-one has ever heard the difference, simply believing that it is polypropylene, so therefore sounds 'better'."

 

What about cap choices in networks?   I have had two identical setups with "cheap" poly's and another with mid-upper grade foil caps and there is definitely a difference in sound that even my ears can hear. Poly caps seem to give off a bolder, grainy, wet sound that seems to exaggerate things, while the foil is more neutral and flatter taking away the peaks and over cooked tones allowing you to hear the subtleties and minute background content. 

[minermark]

 

 

Honestly I think the fact that tubes are high impedance devices means that for the same time constant (RC) you need a much smaller capacitance so you have much more choices to pick from as far as dielectric composition goes. Smaller caps means better quality ones are cheaper. Ever see the size of a 10uF film cap compared to a 10uF electrolytic cap of the same voltage rating? HUGE size and price difference!!!!!!!!!!!!!!!!!!!

Untill you buy/try, you will never know what you are missing......

[Guest thesloth]

 

 

 

Honestly I think the fact that tubes are high impedance devices means that for the same time constant (RC) you need a much smaller capacitance so you have much more choices to pick from as far as dielectric composition goes. Smaller caps means better quality ones are cheaper. Ever see the size of a 10uF film cap compared to a 10uF electrolytic cap of the same voltage rating? HUGE size and price difference!!!!!!!!!!!!!!!!!!!

Untill you buy/try, you will never know what you are missing......

 

 

 

 

Film IS better then electrolytic. Film caps will be larger and more expensive then electrolytic caps. That response was in regard to the original question. I try and always use a quality polypropylene cap in the signal path.

 

 

I am not sure what you want me to buy/try? Ridiculously expensive capacitors? Why? I don't think after a certain price point you can hear/measure any improvement. Using the correct capacitor type for the a specific application isn't expensive.

Edited August 8, 2015 by thesloth

[Fjd]

No discussion of tube amps is complete without including the issue of the so called "audiophile grade" capacitors and attributing sonic qualities to exotic dielectric materials such as bees wax.  This leads to an obvious question (at least to me):  Why is it that discussions about "audiophile grade" capacitors are always in the context of their use in tube type equipment?  Solid state gear uses far more of them, yet I never see discussions about replacing all signal path caps as a means of greatly improving the sound.  Granted, doing pcb rework is a much more difficult task for those without experience, but it can still be done with care and patience.  My views on such caps are well known, and I tend to agree with the premises stated in this excellent paper by Rod Elliott:

 

http://sound.westhost.com/articles/capacitors.htm

 

If anyone has done blind listening tests with tube or ss equipment in which different grades of caps were swapped in and out, with sonic differences being consistently identified, I'm anxious to learn of your results.  I'm not looking to start an ongoing argument as I consider all points of view to be as valid as my own.  Just curious as my own experiments in that area, with very closely matched capacitor values, did not yield any identifiable differences.

 

Maynard

 

 

 

 

Regarding not finding much to read about capacitor swapping in solid state amplifiers, in general, I suspect that one of the most significant impacts of using lots of feedback in a solid state amplifier, in addition to “better measurements,” is the feedback seems to "swamp" out the differences in passive parts, such as capacitors, rendering any impact of passive parts on sound to be negligible, if any. 

 

It would seem to be the same with tube amplifiers where passive parts such as driver tubes, input tubes and capacitors stand a better chance of exhibiting differences in a single-ended amplifier with no feedback to "swamp" the differences compared to the old Williamson or Mullard circuits of the 1950s that had in excess of 20 dB of feedback.

 

Overall, I have serious doubt that many understand how to control the appropriate variables in performing a statistically valid ABX test or know how to properly evaluate the results to derive any meaningful data, let alone understand and evaluate the impact of the experience level of the listener on the results.  Studies done by Soren Bech have shown that 6 trained listeners can provide data that is as statistically reliable as data gathered from 18 untrained listeners. [soren Bech,”Selection and Training of Subjects for Listening Tests on Sound-Reproducing Equipment” Vol. 40, Number 7 pp. 590 (1992).]

 

 

Danger Will Robinson, objective and subjective may just be two different species rather than differing points on the same continuum.  

 

 

 

 

 

 

 

 

 

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Edited August 8, 2015 by Fjd

[minermark]

I guess you could say this was my "Blind" test.

Some years back i picked up a pair of mono blocks, told a buddy i was giomg to go through them and he said he had  some caps he would give me and maybe save me a little scratch.

After getting them and seeing what i needed in the circuit, i found i had enough to do just one amp, minus one cap.

these were better/newer caps but by no means "super audio grade", upon getting one recapped, fired it up, sitting between the speakers about 10' center, i noticed i had to lean the ballance toward the non recapped amp, and the extream highs were noticeable more, coming from the recapped amp, hummmm

[oldtimer]

if you are talking newer especially, and better to a lesser extent versus standard and older, are you not comparing apples to oranges?  The original post assumes equal caps in a set up, not half and half in the same system. I would think newer will always sound better even if they are simply the same as original.   As for the original post there has always been on this forum at least an opinion of when buying vintage speakers you should renew the caps in the crossovers.  No tubes there, so isn't there also talk about caps and solid state?  I realize that is talking speakers rather than amps but there must be some corollary.

[oldtimer]

Quality control is another factor.  Maybe cheaper caps have more variance.  to me, better would mean doing the job as designed, and lasting longer than the alternative.

[Coytee]

Question for some of the.....  more experienced in the crowd....(older)

 

If you go back to the 50's/60's/70's (I'm not sure which era is best), did people still fret over which cap to use or which wire to use or which (brand) of tube?

 

I grew up pretty much on the tail end of the tube era.  I recall the service guy coming out to fix the tv and putting a little tube in there and that is about it.  When I was looking at electronics, the 'new & improved' was the solid state and you could buy a used McIntosh for what seemed to be nothing.

 

I have this view of that era of someone simply grabbing a cap off the shelf to fix something.  Need a new 300B?  Go to the store and get what's on sale.  Need some speaker wire?  What is "speaker" wire?  Go get some of that lamp cord wire and all is well.

 

I wasn't there so if people were neurotic about things then like they can be now, I wasn't old enough to witness it.

 

So I ask, were people as neurotic then as they can be now?

[tube fanatic]

Question for some of the.....  more experienced in the crowd....(older)

 

If you go back to the 50's/60's/70's (I'm not sure which era is best), did people still fret over which cap to use or which wire to use or which (brand) of tube?

 

I grew up pretty much on the tail end of the tube era.  I recall the service guy coming out to fix the tv and putting a little tube in there and that is about it.  When I was looking at electronics, the 'new & improved' was the solid state and you could buy a used McIntosh for what seemed to be nothing.

 

I have this view of that era of someone simply grabbing a cap off the shelf to fix something.  Need a new 300B?  Go to the store and get what's on sale.  Need some speaker wire?  What is "speaker" wire?  Go get some of that lamp cord wire and all is well.

 

I wasn't there so if people were neurotic about things then like they can be now, I wasn't old enough to witness it.

 

So I ask, were people as neurotic then as they can be now?

Richard, I can tell you from first hand experience that 99% of my customers weren't obsessed by anything pertaining to the the tubes or parts in their audio equipment.  Remember, the Scotts, Fishers, and everything else from that era used components which weren't anything special (the exception being some custom built output transformers).  They were typical off the shelf parts and, when they failed, were replaced with the same.  The equipment sounded just fine.  And the same applied to tubes.

Maynard  

[minermark]

Growing up in LA in the 60s i went with my dad every chance i had everywhere he went, if i knew he was going to stop by one of his buds house, i had a list, tubes, Caps, Resistors, some of his buds were into Ham radio like myself, others were into TV/Radio, but all had goodies laying around.

As i recall no one cared one way or another on brands, they used what they could get.

Radio Shack did not exist, mostly small mom/pop tv shops that also were into audio.

Funny the largest cable i remember seeing was speaker wire and it was always an extenision cord of some type, 12Ga tops.

I met some audio nuts, their interconnects were nothing more than small Ga RCAs not unlike the stuff radio shack sold.

I also remember all the guys had speakers of some type and none bragged about them, and i saw some big ones.

[minermark]

 

Question for some of the.....  more experienced in the crowd....(older)

 

If you go back to the 50's/60's/70's (I'm not sure which era is best), did people still fret over which cap to use or which wire to use or which (brand) of tube?

 

I grew up pretty much on the tail end of the tube era.  I recall the service guy coming out to fix the tv and putting a little tube in there and that is about it.  When I was looking at electronics, the 'new & improved' was the solid state and you could buy a used McIntosh for what seemed to be nothing.

 

I have this view of that era of someone simply grabbing a cap off the shelf to fix something.  Need a new 300B?  Go to the store and get what's on sale.  Need some speaker wire?  What is "speaker" wire?  Go get some of that lamp cord wire and all is well.

 

I wasn't there so if people were neurotic about things then like they can be now, I wasn't old enough to witness it.

 

So I ask, were people as neurotic then as they can be now?

Richard, I can tell you from first hand experience that 99% of my customers weren't obsessed by anything pertaining to the the tubes or parts in their audio equipment.  Remember, the Scotts, Fishers, and everything else from that era used components which weren't anything special (the exception being some custom built output transformers).  They were typical off the shelf parts and, when they failed, were replaced with the same.  The equipment sounded just fine.  And the same applied to tubes.

Maynard  

 

I remember when finding a tube in a box/bag, my only thought was can i read the number and will it test good.

[Fjd]

Question for some of the.....  more experienced in the crowd....(older)

 

If you go back to the 50's/60's/70's (I'm not sure which era is best), did people still fret over which cap to use or which wire to use or which (brand) of tube?

 

I grew up pretty much on the tail end of the tube era.  I recall the service guy coming out to fix the tv and putting a little tube in there and that is about it.  When I was looking at electronics, the 'new & improved' was the solid state and you could buy a used McIntosh for what seemed to be nothing.

 

I have this view of that era of someone simply grabbing a cap off the shelf to fix something.  Need a new 300B?  Go to the store and get what's on sale.  Need some speaker wire?  What is "speaker" wire?  Go get some of that lamp cord wire and all is well.

 

I wasn't there so if people were neurotic about things then like they can be now, I wasn't old enough to witness it.

 

So I ask, were people as neurotic then as they can be now?

 

 

 

I would think that the same comments could be said about almost every consumer good today where you have situations that a few obsess about.  For example, I would also venture to guess that people back in the 50's/60's/70's were probably not neurotic about needing to carry a phone everywhere they go, or have a phone with 1,000 aps on it, or fret that the newest phone release is configured for two aps that will not work with their current phone or neurotic about the colors available.  That old black desk phone with a rotary dial or even the wall phone (some families had both) did its job.

 

Now it was pretty cool when we could finally afford to upgrade the service to our first private phone line instead of dealing with the challenges of the old cheaper multiple subscriber party phone line (with a party line any of the subscribers on the line could easily listen in on other subscribers' calls).  If liking the benefits of the private line makes me neurotic....... 

 

 

 

 

 

 

 

 

 

 

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Edited August 8, 2015 by Fjd

[Guest thesloth]

When tube audio was all there was capacitor technology was not that good, caps today outperform them hands down. 

 

The audiophool industry has everyone thinking there are magical components out there that will drastically change your gear.

 

The only place I use electrolytics is the power supply and sometimes the bypass of a cathode. Small values I like Silver Mica or Polystyrene. Larger values I usually go polypropylene.

 

There are many write ups about specific dielectrics and their accuracy, temperature stability, leakage, esr, and distortion characteristics. I am not too sure I would be putting any wax paper caps in my amps.

[Fjd]

I am not too sure I would be putting any wax paper caps in my amps.

 

 

 

I remember when the very old version of the Jupiter bees wax caps would melt in an amp. 

[Guest thesloth]

 

I am not too sure I would be putting any wax paper caps in my amps.

 

 

 

I remember when the very old version of the Jupiter bees wax caps would melt in an amp. 

 

 

 

Tell me about it!!! Even if they didn't melt I wouldn't trust em near any sort of heat because they most likely will drift in value over time. (probably get leaky over time too) Maybe they are okay for crossovers? I couldn't find any specifications on them but if esr is high and or the max ripple current is exceeded they can heat up internally causing them to melt and drift etc.......