Jensen Audio caps, worth the money?

[R.G.]

Playing the audiophile sound game is hardly going to cause psychological damage, it just wastes time and money.

That keyed up the old saying:
Never try to teach a pig to sing. It wastes your time, and annoys the pig.

[Enzo]

Ah RG, I should have known you'd read skeptical literature like Schermer.

[soundmasterg]

Since sound waves move through the air, anything that changes the air will also change the sound. This is basic physics and anyone who has taken physics or has experience with recording will realize this. You can have an amp miked up and have everything in the same position and same settings on the controls, and play and record on two different days and the sounds will be different. Temperature and humidity changes will change the sound, even if your perception of the sounds didn't change from day to day.

Regarding caps....if you throw out ceramics and electrolytics due to their known distortion effects and you just consider film caps and PIO caps, and you make sure you are testing the exact same value between types of caps, then any difference because of the dialectric type will be very small. So small that changing other things in the circuit like part values or voltages will make a much bigger difference in the sound. That said, the differences are something that can be heard, but not really between brands per se...more like between say a polyester cap vs a polypropylene one...but again the differences are very small and likely wouldn't be noticed by 90% of the people out there, and maybe 1% of those remaining 10% might be able to get reliable results in a double blind test.

If you are making your results without doing a double blind test, then your impressions will not be very reliable due to the way we hear. If you are changing over to different cap types without being able to immediately hear the difference such as if you changed between two caps using a switch, then your brain forgets what the first sound was by the time you hear the second sound. You may think you remember, but hearing is one of those senses that is hard to pin down and define, especially since we all hear differently. Going around and calling other people tone deaf because they don't have the same opinion as you or don't hear the same exact thing is you is pretty stupid. It is kind of like arguing about religion.....

Greg

[Enzo]

Our band used to play a local club a lot, the club had a house sound system. It was a large club - held 1500 if I recall the number - and larger than a lot of bands were used to. I made myself available as a (cheap) house sound man for bands used to mixing from stage. I got to know the room and its sound VERY well.

I used to swear i could tell you if it started raining outside. The humidity would affect the sound. First set and sound check the room was fairly empty, sounded one way. Oh and it mattered if you were on the dance floor or up in the stands. Then when the place started to fill up, the bodies absorbed some of the sound, affecting the perceived volume as well as the overall freq response. Then as the club was full, the sweat and breathing would cause third and fourth sets to sound different still. On top of all that progression was the weather/conditions of the day. The fabric of peoples clothing in the winter months had a different effect from the light clothes of summer. Coats hanging on chairbacks made the room sound different from the lack of same in summer.

And so on.

[Randall]

As the OP, I am also a very experienced sound engineer, having worked with numerous famous acts in America over quite a span. While I can concur that humidity, hair, rooms, people, etc are perfectly acceptable variables in how a room/stage sounds, too I would also point to the the very large factor of the stage construction itself, whether hollow or not, and how those resonant freq's affect everything. I must say this is not what my question was about. It is whether $25 Jensen Copper PIO caps are worth the expense, more to the point, in a 50's designed tweed Fender amp. Sorry if I didn't make that clear. I'm biased at this point to say no, and just crank it .

[kleuck]

Yeah, voltage, humidity of the air, phases of the moon can influence the sound, but not the caps construction EXCEPT for the ceramics or the electrolytics cause you KNOW their issues.
Plain non sense.

[Steve Conner]

You might call it nonsense, but that is indeed what we're saying.

To the original poster: I'm sure that if you bought $25 caps you could convince yourself that they made an improvement to the sound. Same idea as that $5,000 bottle of wine. But I'm also sure the amp would sound fine with ordinary commercial-grade caps.

If we're talking about replacing the original caps in a 1950s vintage amp, those could have deteriorated in weird and wonderful ways (for example if moisture gets into them, water has a dielectric constant of 80) so any modern replacements could change the tone drastically.

[soundguruman]

Since sound waves move through the air, anything that changes the air will also change the sound. This is basic physics and anyone who has taken physics or has experience with recording will realize this. You can have an amp miked up and have everything in the same position and same settings on the controls, and play and record on two different days and the sounds will be different. Temperature and humidity changes will change the sound, even if your perception of the sounds didn't change from day to day.

Regarding caps....if you throw out ceramics and electrolytics due to their known distortion effects and you just consider film caps and PIO caps, and you make sure you are testing the exact same value between types of caps, then any difference because of the dialectric type will be very small. So small that changing other things in the circuit like part values or voltages will make a much bigger difference in the sound. That said, the differences are something that can be heard, but not really between brands per se...more like between say a polyester cap vs a polypropylene one...but again the differences are very small and likely wouldn't be noticed by 90% of the people out there, and maybe 1% of those remaining 10% might be able to get reliable results in a double blind test.

If you are making your results without doing a double blind test, then your impressions will not be very reliable due to the way we hear. If you are changing over to different cap types without being able to immediately hear the difference such as if you changed between two caps using a switch, then your brain forgets what the first sound was by the time you hear the second sound. You may think you remember, but hearing is one of those senses that is hard to pin down and define, especially since we all hear differently. Going around and calling other people tone deaf because they don't have the same opinion as you or don't hear the same exact thing is you is pretty stupid. It is kind of like arguing about religion.....

Greg

I said they were tone deaf because:
A. Not musicians, no musical training or skills. They can't hear any difference. "Might" pretend to know how to play guitar, but can't tune it by ear, for sure.
Not because they don't agree with me.
Besides, nobody in this forum agrees with me, most of the time. That's a given...we are all quite accustomed to that.
But I needed to state the other side of the coin. The part that you don't usually hear from the status quot.

I like old coupling caps when the insulation "just" starts to break down. They leak just a little DC, and that changes according to the frequency and volume.
When caps are new, they don't do that. When they are "just" old enough, they do it "just" right.
When caps are too old, they leak too much DC, and the mojo is gone. So you really want 'em at just the right ripeness.

When the caps leak just a hair, that is what gives them that aged sound. But they don't leak constant or consistent. They leak according to how hard they are driven, and according to frequency. That unpredictable slight leakage adds a lot of spice and mojoistic tone.
I have often thought of making deliberately leaky caps, that leak just a bit, to duplicate that aged sound...that would be cool - a - mundous.

[Steve Conner]

When the caps leak just a hair, that is what gives them that aged sound. But they don't leak constant or consistent. They leak according to how hard they are driven, and according to frequency. That unpredictable slight leakage adds a lot of spice and mojoistic tone.
I have often thought of making deliberately leaky caps, that leak just a bit, to duplicate that aged sound...that would be cool - a - mundous.

You should do that The problem with the "ripe" caps is that they'll keep on getting "riper" until they break down completely, and that could happen in a matter of months or days, in the middle of a big gig according to Murphy's law. If you could figure out some circuit that simulated the leakage in a way that would be stable with time, it would be neat.

[R.G.]

I said they were tone deaf because:
A. Not musicians, no musical training or skills. They can't hear any difference. "Might" pretend to know how to play guitar, but can't tune it by ear, for sure.

Let me ask the obvious question - that's a pretty vast assertion. How do you know that?
(1) Have you ever met "them"?
(2) How do you know that "they" are not musicians?
(3) How do you know "they" have no musical traning?
(4) How do you know that "they" have no skills, which is a different thing from training?
(5) Are you aware that musical perception is entirely different from being a musician? Can you define the difference?
(6) How do you know that "they" can't tune a guitar by ear?

Please answer these questions with verifiable facts, not raw assertions and opinions.

It was a common comment in certain scientific circles that one should not make vast assertions based on half-vast data. State your verifiable facts and numbers, please. Otherwise, what you say is a personal opinion, on a par with "I like shrimp better than broccoli." That statement is possibly completely true - and also worthless as a predictor of what anyone else may like.

Not because they don't agree with me.
Besides, nobody in this forum agrees with me, most of the time. That's a given...we are all quite accustomed to that.
But I needed to state the other side of the coin. The part that you don't usually hear from the status quot.

I do like Schermer's sendup of this - heresy does not equal correctness. Just because an assertion does not match the common thinking does not make it correct. It's important to be able to raise opinions contradictory to the status quot [sic]
but the burden of proof lies with the person making the heretical assertion. It ain't true just because it's contrary.

I like old coupling caps when the insulation "just" starts to break down.

You're OK so far in that this is an opinion. I'll spot you that shrimp is indeed better than broccoli.

They leak just a little DC, and that changes according to the frequency and volume.
When caps are new, they don't do that. When they are "just" old enough, they do it "just" right.

However, there's a glaring open spot here. Numbers please. Define "just". Or is it when *your* ears like it? Can anyone else perceive the ripeness? Or is it just in your head? Is it DC that's leaking? Or is it a ratio of ESR to capacitance? Or is it the beginnings of breakover on signal peaks as the cap withstanding voltage declines? How could you measure leakage per frequency? If it's DC leakage that varies with frequency and volume, HOW does that work? Is it linear or nonlinear with frequency and volume? Or frequency more than volume, or volume more than frequency? Is there a breakover point where it gets bigger/smaller?

I'm always eager to learn how things work. Educate me, guru-man.

When caps are too old, they leak too much DC, and the mojo is gone. So you really want 'em at just the right ripeness.

If you haven't or can't measure what's happening, how do you know it's the DC? How, for instance, do you know it's not the rise of ESR? Is it electrolytic caps only, or do film, ceramic, and mica do it too? Or do you believe that a cap is a cap is a cap? They can't all be the same, can they? Does the effect get bigger with more farads? Linearly? Exponentially? Square law? 3/2 law (like the current in a triode)?

You see, if one cannot have some idea how and what varies, one may find museum pieces and appreciate them, but one cannot design things that deliberately capture the effect you've heard.

I have often thought of making deliberately leaky caps, that leak just a bit, to duplicate that aged sound...that would be cool - a - mundous.

Me too - that's why I posted it here, the idea of 'dirtying up' a cap to less perfect. You see, if you don't *measure* what's happening, you can't go tune a good cap to be properly dirty.

I have met people who like to make pronouncements not supported by fact. A lot of these are a little lazy. They can't be bothered to go get the training, skills and/or self-discipline to support their sweeping conclusions. Taking time to get some numbers is too much like work.

I like Steves's comment: if you can measure an electrical difference, there is definitely something there. It may well be audible, but as Enzo notes, it may well be below the threshold of perception. If you hear it, it **may** be there. Or it may not. To nail down that something is in fact happening that you hear, you have to go concoct some way to measure it. If it's really there, it will be there when you do figure out a way to measure it.

[R.G.]

Ah RG, I should have known you'd read skeptical literature like Schermer.

I like the way Schermer says some things. In my opinion, some of it goes a little far, but hey, that's my opinion.

I used to swear i could tell you if it started raining outside. The humidity would affect the sound. First set and sound check the room was fairly empty, sounded one way. Oh and it mattered if you were on the dance floor or up in the stands. Then when the place started to fill up, the bodies absorbed some of the sound, affecting the perceived volume as well as the overall freq response. Then as the club was full, the sweat and breathing would cause third and fourth sets to sound different still. On top of all that progression was the weather/conditions of the day. The fabric of peoples clothing in the winter months had a different effect from the light clothes of summer. Coats hanging on chairbacks made the room sound different from the lack of same in summer.

All of those are dead on, verifiable facts, I think. Humidity does affect sound transmission in air measurably. So does the presence of people, the distribution of the people in the place, the amount and type of fabric distributed around, all of which affect the absorption of sound, especially at higher frequencies. I've read just a bit about the design of concert halls, and seen some of these mentioned.

[Enzo]

Observations totally anecdotal on my part, but when they hang drapes on walls to tame reflections< I don't see a whole lot of difference if there are coats draped on chairs.



And I'd agree, if I had one complaint about Schermer, it might be he can get a bit too smug.

[soundguruman]

You should do that The problem with the "ripe" caps is that they'll keep on getting "riper" until they break down completely, and that could happen in a matter of months or days, in the middle of a big gig according to Murphy's law. If you could figure out some circuit that simulated the leakage in a way that would be stable with time, it would be neat.

It's cool to hook a scope, and watch the leakage, as you play guitar notes thru the amp.
The leakage increases and decreases, according to the music played.
It actually does things that you would never expect a capacitor to do...I mean you think of a cap as blocking DC, but there's a lot of variation in micro DC voltages.
And of course, as you might expect, different cap leaks in different patterns. It's like a unique signature of leakage.

Yes cap does get over-ripe with age, and leaks too much which = muddy sounds. As the grid is driven more and more positive..above where it will operate in a linear mode.

But what has always fascinated me is what cap and grid will do when amp is sustaining a guitar note. Like when original note breaks into octave higher note, as guitar is sustaining.
It does not behave as you would predict. You will just need to see that for yourself. Very unexpected voltage wanderings.

[Bruce / Mission Amps]

...
Yes cap does get over-ripe with age, and leaks too much which = muddy sounds. As the grid is driven more and more positive..above where it will operate in a linear mode....

Guess it depends and the definition of linear.
Seems like if it leaked negative voltage to the grid, then it would be non-linear. Positive leakage... wouldn't that + voltage possibly cause the stage to saturate easier (if you can say that with a simple class A preamp triode, etc.)
But maybe you were talking about power tubes, which would also cause the bias condition to run slightly (read VERY SLIGHTLY) underbiased... well, a very tiny amount compared to where set with non leaking coupling caps.
So strap a 10M-22M 1/2 watt resistor across your coupling caps gents.

[R.G.]

It's cool to hook a scope, and watch the leakage, as you play guitar notes thru the amp.
The leakage increases and decreases, according to the music played.

OK, we may be getting somewhere.
(1) Which cap do you hook to? Or do all caps do this in synchronism?
(2) Extension of (1), really - filter caps or coupling caps?
(3) Which oscilloscope leakage probe did you use, and how did you hook it up?
[bearing in mind that in several decades of using o'scopes I've seen voltage probes, sampling probes, current probes and temperature probes, but no leakage probes]

It actually does things that you would never expect a capacitor to do...I mean you think of a cap as blocking DC, but there's a lot of variation in micro DC voltages.

(4) How do you know it's the cap leaking, and not the circuits to either side of it?
(5) How did you measure the micro (!?) DC voltages (er, micro DC voltage changes??) in the face of the other DC values in the amp? If you still have many volts across the cap, how did you measure the micro DC voltages in the face of that much common mode other stuff?

And of course, as you might expect, different cap leaks in different patterns. It's like a unique signature of leakage.

Actually, at the macro level, I would not expect that. Sure, when you get down to measuring finely enough, you can measure electrons per femtosecond or something. But
(6) what do these patterns look like?
(7) what did you use to see the patterns?

Yes cap does get over-ripe with age, and leaks too much which = muddy sounds.

(8) All caps? Filter caps? Coupling caps? Cathode caps?
(9) does the unique signature change as they age?
(10) If so, is it possible for caps to drift into the same signature and then away from the confluence of signatures with time?
(11) How would one take a "leakage print" so they could ... heh, heh... sell custom, registered unique leakage-printed caps?
(and you know there are tweekos reading that will go "HEY...!"

As the grid is driven more and more positive..above where it will operate in a linear mode.

(12) So - coupling caps??? Do film coupling caps demonstrate a "ripening" process over time?
(13) [This one's for the tweekos reading this ] Can you do a "pre-ripening" process to get them just right for a little while before they're put into service?
(14) Once ripe, how long do they stay ripe before going rotten?

If you're trying to enlighten us about ripening capacitors, you'll need to fill in some blanks so that this doesn't just look like you made it up to sound good.

I ...want... to believe. Help me. Got any answers?