New John Kenny Power Supply....

[pkane2001]

5 minutes ago, jabbr said:

 

Hmm...

 

I would try:

 

1) use a battery alone (without meanwell)

2) use a battery and plug the meanwell into something else

3) xformer isolate the spectrum analyzer

etc...

a) not enough info to draw firm conclusions,

b) big point: that leakage current is not typically just at the fundamental AC frequency rather higher frequencies generated by the switching circuitry.

 

There are only a few possibilities for leakage.

 

1. Through ISO-R

2. Through the common, in-the-wall wiring and ground

3. Through the air, RF/EMI

4. Through the AP power supply: this was already disproved

 

I asked Amir to redo the test with AP and ISO-R on independent circuits (one on a battery/UPS) to eliminate #2. He didn't think this kind of leakage was possible. Still looks possible to me, although not likely.

 

[pkane2001]

1 minute ago, jabbr said:

What is your definition of "leakage" and how are you measuring it? I've asked for a schematic. Simply measuring the output of a DAC is not measuring the leakage current.

 

I didn't measure this. Amir did. He measured ISO-R powered by LPS-1, powered by MeanWell SMPS into a USB-powered DAC. He posted AP-generated power spectrum showing AC fundamental and harmonics at the output of the DAC. The fundamental was about 20dB above noise floor. When MeanWell was replaced with a lab linear power supply, these frequencies disappeared from the DAC output. You'll find a lot more details on the ASR thread, no reason to duplicate it here.

 

[pkane2001]

2 minutes ago, jabbr said:

 

Well the graphs were posted here and you are talking about leakage here. If I wanted to participate in another discussion somewhere else I could and would. Some measurements were made but we have no reason beyond hand waving to determine that these are leakage currents. There are well known ways to analyze and measure leakage currents heck there are even standards that discuss this. It isn't good form to draw conclusions about things that aren't being measured, but who knows? Why would you draw conclusions about leakage currents when you are simply measuring DAC output? I mean thats more appropriately PSRR (I am assuming with the very little info I have). PSRR and leakage current are two different things.

 

How about you read the ASR thread, and then come back here so we can discuss your questions. It makes no sense for me to duplicate everything that's been tested and reported there. It's multiple pages of posts and contains many tests and multiple measurements.

[pkane2001]

1 minute ago, jabbr said:

I think the Meanwell issue is not that interesting actually and am wondering why this issue is still being discussed???

 

It's interesting because LPS-1 is sold with MeanWell SMPS. And because LPS-1 is claimed to eliminate all AC leakage currents and ground loops. Having AC frequency and harmonics introduced into the DAC output that didn't have them without these Uptone Audio products is, in my opinion, an important thing to know for someone considering their purchase (as I was).

 

Quote

*The LPS-1 completely blocks the path of AC leakage currents from entering into the portion of your audio system it is connected to. This is a complex and not broadly understood area, but our research—and likely some of your own component listening experiments—proves that reducing leakage currents and loops is one of the most important final steps to improving audio system performance.

 

[pkane2001]

22 minutes ago, jabbr said:

Again what does this have to do with battery supplies? and the point has been made over and over in other threads ... why the perseveration?

 

Beats me. You were responding to a post regarding LPS-1 reported leakage with a set of questions. I obliged with a description you were seeking. If these questions were rhetorical, then I missed that memo, but I certainly wasn't the one that started down this path.

[pkane2001]

14 minutes ago, Superdad said:

 

I just posted the first of the proof over in the ASR thread.  Go there.

 

Looks like a good response, Alex. I believe you are saying the cause of the AC frequencies at the DAC output is  #3 in the list I posted earlier:

 

1 hour ago, pkane2001 said:

1. Through ISO-R

2. Through the common, in-the-wall wiring and ground

3. Through the air, RF/EMI

4. Through the AP power supply: this was already disproved

 

Let's see if Amir can confirm.

[pkane2001]

13 minutes ago, jin said:

 

The culprit is air.

Move to Pluton to get the best of LPS1, if BS was music...

 

 

Eliminating atmosphere isn't going to stop EMI. Even on Pluto the problems would persist. Of course, lack of air may make it a bit harder to hear the music...

 

Then, again, looks like EMI was only an issue with Alex's setup and could not be reproduced in Amir's, so there may yet be another leakage path from the four that I listed.