so measure the difference and we can possibly understand what to look for in the specs
or did you "just listen"?
swap back and forth ro rely on memory?
blinding?
Blind, fast switching without clues - good statistics, measurements proving level matching, frequency response didn't change - then I'll consider the possibility that whatever you "heard" was related to the signals through the 2 types of Caps
or did you "just listen"?
swap back and forth ro rely on memory?
blinding?
Blind, fast switching without clues - good statistics, measurements proving level matching, frequency response didn't change - then I'll consider the possibility that whatever you "heard" was related to the signals through the 2 types of Caps
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I used to believe that caps of good quality should be sufficient. I knew that polypropylene is much better than polyester. But this is the first time that I experimented with different polypropylene caps. As the resolution of my system improves it becomes easier for me to hear the difference.
I am planning more tests with caps that performed better in tests posted/published online. But I consider these caps expensive and do not want to blindly buy a whole bunch. Thus I would like see what experiences others might have to guide my tests.
I am planning more tests with caps that performed better in tests posted/published online. But I consider these caps expensive and do not want to blindly buy a whole bunch. Thus I would like see what experiences others might have to guide my tests.
As different caps measure differently it is not surprising that in certain circumstances they can sound different too. However, getting the circuit right is the first priority. This alone should reduce the difference between caps because a cap with almost no signal voltage across it can't generate much distortion.
Also, bear in mind that if someone will pay good money for it then someone else will fake it. The more expensive the cap, the greater the temptation. I can't remember where, but I did see an expensive 'audiophile' cap with an ordinary cap inside it. You won't know except by detailed objective testing or cutting it open.
Also, bear in mind that if someone will pay good money for it then someone else will fake it. The more expensive the cap, the greater the temptation. I can't remember where, but I did see an expensive 'audiophile' cap with an ordinary cap inside it. You won't know except by detailed objective testing or cutting it open.
Even then, they would get away with it by saying it looks ordinary, but has in fact been specially selected, has been subjected to a special break-in, and the case itself makes all the difference. And numbers of people, including in this forum would rush to their defense.
As Barnum said, one is born every minute, and now with >7E9 people on earth, that's more like one every second. A huge potential market.
A few years back on this forum, I saw people pulling the plastic wrapping from caps claiming they improved the sound quality by doing that! And even longer ago audiophiles claimed that using a black marker and "painting" the side of a CD makes it sound better.
Hi,
Isn't smaller value caps more effective in shunting high frequency signals. We are living in such a EM filled environment, even though their frequencies are high, their intermodullation products may well be interacting with signals in the amps.
Returning to cxaps sounds, I built Cyril's apparatus and different caps do have significant different hormonic contents, at least on steady state. The 'audio caps' tended to have significant more 2nd and/or 3rd hormonic contents. I woder whether this made them sounded ' nice ' just like the valve amps.
AW
Isn't smaller value caps more effective in shunting high frequency signals. We are living in such a EM filled environment, even though their frequencies are high, their intermodullation products may well be interacting with signals in the amps.
Returning to cxaps sounds, I built Cyril's apparatus and different caps do have significant different hormonic contents, at least on steady state. The 'audio caps' tended to have significant more 2nd and/or 3rd hormonic contents. I woder whether this made them sounded ' nice ' just like the valve amps.
AW
You are not alone in the world, you may want to look at here
Humble Homemade Hifi
You will not find objective explaination of different "sound" with various capacitors, same as with various amps. So, only intuition and empiric experience are your partners in this subject.
Put a blinking neon sign around this! In one test, I compared an ultra-expensive Teflon cap to a cheap nonpolar electrolytic used as coupling caps. By following good engineering practice (i.e., high load impedance compared to cap impedance at audio frequencies), I was unable to hear any difference in a controlled test. No-one else has been able to do so either- but I still have the switchbox and anyone is welcome to come over and try!
Yes, the first time I became aware of that was when reading D.Self and his list of 8 distortions. He makes the case for low AC and low DC voltages across the DC blocking caps in his power amplifier designs. Although I didn't notice it expressly defined, he implies that low distortion results from low voltages as a consequence of "oversizing" capacitors where they must pass signal.
I would bet the rest of the system in that test had sound quality level corresponding to the interstage electrolytics. Only in this case one could not distinguish teflon from lytic.
Sometimes you, experienced guys, simply tell stories like "don't worry, be happy" with all your hi-fi ...
Its a nice advise, match impedances and be happy.
Do capacitors distort? Mostly below the limits of my setup, but some 5% clearly distort.
I have the following layout to test them:
- filtered 1KHz, distortion 160db down
- test jig RC lowpass corner frequency 1KHz
- notch filter, 1KHz 75db attenuation
- HP 3581A wave analyzer, noise limit -150dbV (10Hz BW)
I tested about 300 capacitors, 150 one or two of a kind, and 150 in groups of 60,33,17,15,12,5. The one or two of a kind include precision, pulls from old equipment and TV's, ages 10-80 years old, oil, polypropylene, polystyrene, mylar(polyester), paper, wax, Vitamin Q, X2, "orange drops", film/foil, metallized film, stacked foil types. The grouped caps were modern polyester metallized film and stacked foil types (ie., EVOX-RIFA MKK0 0.1uF, 100V).
Values tested were 0.01uF, 0.1uF, 1uF.
Out of the 300 tested, 15 showed distortion above the noise limit of my equipment (-150 dbV, 32 nV). 5 of them were from the "one or two of a kind" lot, and 10 from the groups lot.
Common to bad caps:
- distortion at least 20db above eqpt noise
- small, cheap, older caps
- compromised seal and/or lower DC resistances
Common to good caps:
- small, cheap, newer caps
- old large caps
- hermetically sealed caps (includes Vitamin Q)
Wierd stats: within the groups, caps typically had unmeasurable distortion except for one or two exceptions. Those had remarkably high harmonic levels (-110 to -140 dbV. Not a normal distribution.
I measured a handful of ceramic hi-K capacitors (not part of the 300 film caps), and for the range of values tested (.01uF, 0.1uF, 1uF) they all distorted. I had previuous experience with them while breadboarding a power amp when I chose 1uF ceramics 'cause they were small. The lower bass sounded "off" and had considerable measurable added harmonic content. Replacing them with film caps fixed the problem.
I didn't measure electrolytics because I needed to bias them, and they are usually used in power supply decoupling where the audio voltage across them is very small and is rejected by the power supply rejection ratio (PSRR) of the circuit.
It would take many thousands of samples to make a clear connection between capacitor type and distortion. With only 300 samples I could not make that connection. There was no "in your face" proof that any type consistently causes distortion (except for hi-K ceramics).
-Paul
I have the following layout to test them:
- filtered 1KHz, distortion 160db down
- test jig RC lowpass corner frequency 1KHz
- notch filter, 1KHz 75db attenuation
- HP 3581A wave analyzer, noise limit -150dbV (10Hz BW)
I tested about 300 capacitors, 150 one or two of a kind, and 150 in groups of 60,33,17,15,12,5. The one or two of a kind include precision, pulls from old equipment and TV's, ages 10-80 years old, oil, polypropylene, polystyrene, mylar(polyester), paper, wax, Vitamin Q, X2, "orange drops", film/foil, metallized film, stacked foil types. The grouped caps were modern polyester metallized film and stacked foil types (ie., EVOX-RIFA MKK0 0.1uF, 100V).
Values tested were 0.01uF, 0.1uF, 1uF.
Out of the 300 tested, 15 showed distortion above the noise limit of my equipment (-150 dbV, 32 nV). 5 of them were from the "one or two of a kind" lot, and 10 from the groups lot.
Common to bad caps:
- distortion at least 20db above eqpt noise
- small, cheap, older caps
- compromised seal and/or lower DC resistances
Common to good caps:
- small, cheap, newer caps
- old large caps
- hermetically sealed caps (includes Vitamin Q)
Wierd stats: within the groups, caps typically had unmeasurable distortion except for one or two exceptions. Those had remarkably high harmonic levels (-110 to -140 dbV. Not a normal distribution.
I measured a handful of ceramic hi-K capacitors (not part of the 300 film caps), and for the range of values tested (.01uF, 0.1uF, 1uF) they all distorted. I had previuous experience with them while breadboarding a power amp when I chose 1uF ceramics 'cause they were small. The lower bass sounded "off" and had considerable measurable added harmonic content. Replacing them with film caps fixed the problem.
I didn't measure electrolytics because I needed to bias them, and they are usually used in power supply decoupling where the audio voltage across them is very small and is rejected by the power supply rejection ratio (PSRR) of the circuit.
It would take many thousands of samples to make a clear connection between capacitor type and distortion. With only 300 samples I could not make that connection. There was no "in your face" proof that any type consistently causes distortion (except for hi-K ceramics).
-Paul
