Using Batteries to Bias crossovers into Class A, how does it work? - Page 3 - diyAudio
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Old 8th July 2008, 03:26 AM   #21
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Hello Sy

Not a criticism just curious

I found the Audio Magazine Walter Jung tests articles

http://waltjung.org/PDFs/Picking_Capacitors_1.pdf

http://waltjung.org/PDFs/Picking_Capacitors_2.pdf

http://waltjung.org/PDFs/A_RealTime_...or_Quality.pdf


Parent page lots of good stuff

http://waltjung.org/Classic_Articles.html

Rob
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Old 18th December 2013, 11:19 AM   #22
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Default Charging caps?

Hello,

Have been thinking about this and how it MIGHT be making a difference (as far as I can see no accurate blind tests have ever been done by those claiming a difference. And as easy as it would be to extend a switch out that applies and removes the voltage, with no label on it and have people listen and report their favorite switch postion, seems quite easy to do so.

Looking at the articles Cycil Bates did on capacitors - he found that biasing electroylitic caps did improve distortion, but the effect was widely variable and once the optimum voltage was reached actually produces more distortion, not less.

Now the distortion could be pleasant and that could be what is being reported as it is unlikely that just by guessing at 9 volts you get the optimum results. But more likely the distortion you are getting is just pleasant.

Now personally I am going for accuracy, but whatever floats your boat.
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Old 18th December 2013, 05:02 PM   #23
badman is offline badman  United States
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Quote:
Originally Posted by starkeyg View Post
Now personally I am going for accuracy, but whatever floats your boat.
Pretty glib assessment, given that there has been evidence of lowered distortion when used correctly. I think most of us are going for accuracy on this forum, with a few "damn the torpedoes" subjectivists keeping the engineers on their toes. I've personally found it to be of audible benefit with cheap mylars.

Regarding ESR in the years old discussion, there could be extra issues from two larger caps in series vs. one smaller cap, but there could also be advantages. Consider the case of a single part value, say 5uF. For a 5uF capacitor, you'd need to use either one, or 4 in series-parallel. While the series/parallel case remains constant in terms of ESR/ESL (with the exception of the short leads and joint losses), the power handling quadruples (or more, real world), along with the reduced voltage/current through each cap. Most of the time, a reduction in power in a passive component leads to better performance, has been my experience.
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Old 18th December 2013, 09:03 PM   #24
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Sorry, but don't consider that any more glib that constant assessments that it sounds better, no controls needed as we know better statements.

Pretty easy to do a controlled listening experiment, just need a switch in the circuit, but the people who keep posting how great this is just can't be bothered and I guess any skeptic is supposed to provide the evidence for them. Seems lazy and vague at best as they will not even try to document "the improvement".

You can like anything you wish, but please do not post it as fact unless you are willing to provide some data to support your view. Expecting others to join on faith alone makes it a religion, not science.
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Old 20th December 2013, 03:23 AM   #25
dlp4341 is offline dlp4341  United States
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Default DC current in your XO

In the old days, we had wet and dry circuit telephone prs.
Dry circuits had no DC on the pairs Wet circuits had 24 or 48 VDC. on them.
Since the cables (high pr count ) had splices every few hundred feet, a long cable would have lots of splices. Each splice would introduce some noise, or detect RF from a near by radio station. It was not practical to resplice a cable.
So a DC bias called sealing current was connected to the bad pairs. This current would break down the resistance of poor splices. Is this class A ? and a dry ckt class B ? And why at low levels, the Wet ckt would sound clearer?

Don
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Old 20th December 2013, 11:39 AM   #26
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That's interesting Don. Do you think there is any documentation of the effect? If it was done by the phone company, there should be.
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Old 20th December 2013, 02:15 PM   #27
dlp4341 is offline dlp4341  United States
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Pano

Do a Google search on sealing current

Don
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Old 20th December 2013, 04:52 PM   #28
badman is offline badman  United States
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Quote:
Originally Posted by starkeyg View Post
Sorry, but don't consider that any more glib that constant assessments that it sounds better, no controls needed as we know better statements.

Pretty easy to do a controlled listening experiment, just need a switch in the circuit, but the people who keep posting how great this is just can't be bothered and I guess any skeptic is supposed to provide the evidence for them. Seems lazy and vague at best as they will not even try to document "the improvement".

You can like anything you wish, but please do not post it as fact unless you are willing to provide some data to support your view. Expecting others to join on faith alone makes it a religion, not science.
You claimed there was a measured distortion lowering effect. And you don't understand the basic operation of how someone would have to AB them- you can't just switch the battery out of the circuit to test it- you'd have to bleed the DC and also control for the series cap parasitics compared to a single cap to compare like-like.

You're so eager to look correct that you not only ignore your own technical statements about them, but also falsely claim that people are passing subjective opinions off as fact. Nobody has done that.
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Old 20th January 2014, 02:34 PM   #29
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Gee, you are great at name calling, first Glib, now to dumb to understand.

If you put half that much effort into giving any data at all to back up claims "it's wonderful" you might accomplish something.

Seems you are allergic to blind testing as it might not give the results you demand and feel data is for others who aren't so smart they think anything you claim is complete and utter truth.

Claim to be the second coming if you wish. Just don't expect me to believe anything you spout.

Have a nice day.
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Old 20th January 2014, 09:26 PM   #30
badman is offline badman  United States
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There was no "name calling".

You presented a statement that Cycil Bates had presented measurements indicating lowered distortion- why ignore that piece of evidence? Does it fail to meet your standards, and if so, why present it?

Care to comment on the potential improvements offered by a series/parallel connection compared to a single equal value component?
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