Would not be valid to use a power amp so to drive 28V RMS to a 100uF /100V non polar electrolytic? We are talking speakers anyway. 100W RMS is typical. Or 22uF.
100uF NP vs Solen 100uF series, 8 Ohm 200W dummy shunt, a voltage divider to tap off for the THD spectrum analyzer, a graph for power amp to dummy VS through electrolyte or plastic. Cool, but we have to ask the solid state branch to give us a hand. They have large dummies.
100uF NP vs Solen 100uF series, 8 Ohm 200W dummy shunt, a voltage divider to tap off for the THD spectrum analyzer, a graph for power amp to dummy VS through electrolyte or plastic. Cool, but we have to ask the solid state branch to give us a hand. They have large dummies.
Xover distortion was not found by SY. Case closed as far as I am concerned. I just feel an itch to see the THD in real life power VS film. Because I have used back to back electrolytics with 9V battery on their midpoint and sounded cleaner. Both in preamp's input and in speakers. I have only 30W dummy bcs I make triode tube amps. If I had a 200W dummy I would have done the test already. We had 1kW at my old workplace, we ordered that from someone who was making resistances for electric heaters. And it was cross wound to cancel inductance. Big as a baseball club.
salas said:
Depends on the slope and alignment, right?
I constructed a series filter for my 3-ways so I could use them while I finished the active amp. The big cap was 43uF - about $15.00 from Solen.
The crossover parts can cost as much or more than a quality driver, but is it the place to scrimp? Perhaps in a commercial effort, and there's been more than enough criticism of the manufacturers using cheap electros.
I'm not one to use the high priced item for the sake of it costing more, there needs to be a fairly good reason. The reason, for me, is like I said above - peace of mind. I won't need to wonder if the speakers sound is degrading.
salas said:
In my X-over there is a 35 uF cap and it gets expensive. I'd like to see some measurements on caps of this value.
But I would say that we are not finding anything to be alarmed about. I'm not surprised. Most the time when you look at this kind of thing in detail you don't find a smoking gun. Even though a couple more tests and some different people, I may even try it, and we can settle this once and for all. Personally I'd like that.
''Depends on the slope and alignment, right?
I constructed a series filter for my 3-ways so I could use them while I finished the active amp. The big cap was 43uF - about $15.00 from Solen.
The crossover parts can cost as much or more than a quality driver, but is it the place to scrimp? Perhaps in a commercial effort, and there's been more than enough criticism of the manufacturers using cheap electros.
I'm not one to use the high priced item for the sake of it costing more, there needs to be a fairly good reason. The reason, for me, is like I said above - peace of mind. I won't need to wonder if the speakers sound is degrading.''
In such a case you did well. But I have made 3Way speakers using 200uF in the low pass section. Bulky and costly.
My current 3Way uses 150uF in series with the mid driver (crosses low). I have used BC (Philips) there, could hear it, then Blackgate NP , I could still hear it but it was nicer, until I redesigned the bandpass having the 2mH coil before the cap. It went out of the sonic picture completely then.
Now that I think of it, I remember the case of using better coupling caps in Benchmark DAC1. I used Auricaps, tossing away smd electrolytics. It was a very big upgrade. In parallel, it was DIY audio member ''rdf'' doing his. He used BGs and had shrill stuff along very nice stuff. A kind Englishman let him know that it was a peculiar HF vibration in BGs that would not go if he did not remove the plastic shroud and damp em. So rdf stripped em and encapsulated them in resin. He could not believe that it was real! Shrill stuff gone!
So that is why I thought of feeding less bandwidth in my 150uf series ones, to avoid exciting potential cap's self vibrations higher, and it worked. Maybe it was not that, but it worked for some reason.
Then Clarity Cap (ICW) of Wales, made scientific DBT tests with Salford Uni (GM, UK) and found that the reason that polycaps had sonic signatures long reported by client speaker manufacturers (B&W also) was the fact that any cap contracts and repels along with signal. They saw it with interferometry too. One they purposely made loose enough, could be heard singing along with music! Like and ELS speaker! They made construction efforts with that in mind and there you are with Clarity Caps for speakers to chose among others.
All that leads me to a thought. There is no crossover distortion phenomenon that we kill with poly or bias. We either use more stable poly or we stabilize electrolytics dimensionally, hence vibrationally.
JBL uses 9V in K2. That would be say 35V if to work still biased, when driven hard, wouldn't it? So it must not be crossover distortion. SY found no trace of it. Bcs they surely heard the K2 cleaner, there must be something at work.
They ain't boutique manufacturers endorsing some Bybee ''Golden Godess Speaker Bullets'' $4200 input binding post purifying bridges upgrade.
I don't think its a JBL marketing gimmick. I have heard it too.
Also when I used poly caps in solid state preamps I could detect each one's sonic signature very easily. Same caps in tube preamps with 240VDC bias to block out, could not detect them. Stabilized?
Hmmm....
I constructed a series filter for my 3-ways so I could use them while I finished the active amp. The big cap was 43uF - about $15.00 from Solen.
The crossover parts can cost as much or more than a quality driver, but is it the place to scrimp? Perhaps in a commercial effort, and there's been more than enough criticism of the manufacturers using cheap electros.
I'm not one to use the high priced item for the sake of it costing more, there needs to be a fairly good reason. The reason, for me, is like I said above - peace of mind. I won't need to wonder if the speakers sound is degrading.''
In such a case you did well. But I have made 3Way speakers using 200uF in the low pass section. Bulky and costly.
My current 3Way uses 150uF in series with the mid driver (crosses low). I have used BC (Philips) there, could hear it, then Blackgate NP , I could still hear it but it was nicer, until I redesigned the bandpass having the 2mH coil before the cap. It went out of the sonic picture completely then.
Now that I think of it, I remember the case of using better coupling caps in Benchmark DAC1. I used Auricaps, tossing away smd electrolytics. It was a very big upgrade. In parallel, it was DIY audio member ''rdf'' doing his. He used BGs and had shrill stuff along very nice stuff. A kind Englishman let him know that it was a peculiar HF vibration in BGs that would not go if he did not remove the plastic shroud and damp em. So rdf stripped em and encapsulated them in resin. He could not believe that it was real! Shrill stuff gone!
So that is why I thought of feeding less bandwidth in my 150uf series ones, to avoid exciting potential cap's self vibrations higher, and it worked. Maybe it was not that, but it worked for some reason.
Then Clarity Cap (ICW) of Wales, made scientific DBT tests with Salford Uni (GM, UK) and found that the reason that polycaps had sonic signatures long reported by client speaker manufacturers (B&W also) was the fact that any cap contracts and repels along with signal. They saw it with interferometry too. One they purposely made loose enough, could be heard singing along with music! Like and ELS speaker! They made construction efforts with that in mind and there you are with Clarity Caps for speakers to chose among others.
All that leads me to a thought. There is no crossover distortion phenomenon that we kill with poly or bias. We either use more stable poly or we stabilize electrolytics dimensionally, hence vibrationally.
JBL uses 9V in K2. That would be say 35V if to work still biased, when driven hard, wouldn't it? So it must not be crossover distortion. SY found no trace of it. Bcs they surely heard the K2 cleaner, there must be something at work.
They ain't boutique manufacturers endorsing some Bybee ''Golden Godess Speaker Bullets'' $4200 input binding post purifying bridges upgrade.
I don't think its a JBL marketing gimmick. I have heard it too.
Also when I used poly caps in solid state preamps I could detect each one's sonic signature very easily. Same caps in tube preamps with 240VDC bias to block out, could not detect them. Stabilized?
Hmmm....
gedlee said:
How will the results be different? One test or a thousand, if done properly will yield the same result.
I thought the idea of crossover distortion in a cap was krap to begin with, and if it did exist would not be audible. I'm glad this has been shown to be the case, but as usual, the simple truth is never good enough. It needs to be retested and bickered about endlessly. The voltage wasn't high enough, or low enough. The cap was not the right size, voltage, colour. The temperature at the time of the test wasn't right, or it was cloudy out or the was sunspot activity, or the moon was in the seventh house...
What's wrong with saying: "I was mistaken, let's take this new info and move on"
John, to be fair, he's right that it isn't definitive, but I don't see him making claims or excuses to the contrary, either. You don't think it's there, I don't think it's there, and if Earl will not mind me putting words in his mouth, I think he is probably a lot more on the "doubt it" side, now.
salas said:
Here's an excerpt from the K2 product paper on the cap baising thing. Just click the preview to get the PDF document.
An externally hosted image should be here but it was not working when we last tested it.
best
LC
bi-polar electrolytics
Any of the experts discussing this issue have insights into the electrochemistry of electrolytic capacitors? Non-electrolytic capacitors don't have an electrolyte. The sole purpose of the electrolyte in an electrolytic capacitor is to maintain the dielectric capacity and integrity of the (aluminum, tantalum) oxide layer formed on the (+) side of the foil, due to the small leakage current flowing while the foil is charged anodically.
What happens during an AC signal passage is open to speculation, as it would depend on the breakdown voltage of the anodic film, surface texture and porosity of that in situ film, conditions it formed under initially, etc. Anyone measure this or come up as to a theory of what occurs?
So to speculate as to some ill-defined mechanism causing low signal degradation and loss of detail would seem imprudent to this electrochemist w/o a great deal of research and testing. I doubt that a 9 volt bias would be adequate to prevent the failure of the dielectric causing distortion during AC voltage swings of much greater magnitude (if indeed depolarization of the anodic film is occurrfing at all and causing this distortion)
John L.
Any of the experts discussing this issue have insights into the electrochemistry of electrolytic capacitors? Non-electrolytic capacitors don't have an electrolyte. The sole purpose of the electrolyte in an electrolytic capacitor is to maintain the dielectric capacity and integrity of the (aluminum, tantalum) oxide layer formed on the (+) side of the foil, due to the small leakage current flowing while the foil is charged anodically.
What happens during an AC signal passage is open to speculation, as it would depend on the breakdown voltage of the anodic film, surface texture and porosity of that in situ film, conditions it formed under initially, etc. Anyone measure this or come up as to a theory of what occurs?
So to speculate as to some ill-defined mechanism causing low signal degradation and loss of detail would seem imprudent to this electrochemist w/o a great deal of research and testing. I doubt that a 9 volt bias would be adequate to prevent the failure of the dielectric causing distortion during AC voltage swings of much greater magnitude (if indeed depolarization of the anodic film is occurrfing at all and causing this distortion)
John L.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.