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AC Filtering, Grounding Boxes, Linear PSU and Balanced Power.


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Oh, you started out with it unbalanced?   That's interesting that it is running more quietly now.  From what I've been reading, any hum that can be heard with unbalanced ITs is due to the presence of DC offset coming in from the mains, but I guess your transformer somehow doesn't "see" the DC offset, after center-tapping the secondary for balanced output.  ???

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52 minutes ago, YashN said:

Some simple experiments and captures regarding the direct Computer-to-DAC, with various power supplies including a DIY Linear Regulated PSU for the DAC, and a Custom USB Connector done during the Dec 2017 - Jan 2018 holidays (so last year), a ripe time for DIY as usual.

 

Well done !!! 

I can relate very closely to much of what you have done here.

Unfortunately, the closed minded Objective set will ignore your evidence and continue on their merry way claiming there is nothing wrong with normal USB implementation and keep dishing out their flawed advice.

 

Perhaps you can put this post in a blog for easy reference by others ?

Also, it deserves posting in a more friendly area of the Forum such as the Uptone area where members trying to sort out these problems can more readily locate this information.

 

Kind Regards

Alex

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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1 hour ago, sandyk said:

Unfortunately, the closed minded Objective set will ignore your evidence and continue on their merry way claiming there is nothing wrong with normal USB implementation and keep dishing out their flawed advice.

 

You are unnecessarily degrading the friendliness of the forum by directing nasty criticisms against a hypothetical entity.  Even if you were defending your position in a genuine disagreement, you should do it politely.  Gratuitously throwing insults in response to non-existent enemies is inexcusable.  I hope you find another forum to vent your spleen.

Mac Mini (2012 i7) > HQPlayer > RME ADI-2 v2 > Benchmark AHB-2 > Thiel 3.7

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25 minutes ago, Bob Stern said:

 

You are unnecessarily degrading the friendliness of the forum by directing nasty criticisms against a hypothetical entity.  Even if you were defending your position in a genuine disagreement, you should do it politely.  Gratuitously throwing insults in response to non-existent enemies is inexcusable.  I hope you find another forum to vent your spleen.

 

 You haven't recently been labelled as a Liar in the General Area of the forum , have you ?

 A couple of members here mercilessly attack almost every post that I make in the General Area of the forum.

I agree though that my comments were coloured as a result of these recent personal attacks, and shouldn't have been made.

 e.g.

  https://www.computeraudiophile.com/forums/topic/38000-operating-systems-and-there-sound-signatures/?page=7&tab=comments#comment-759699

 

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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6 hours ago, YashN said:

And very nice pix and process. Thanks for sharing!

 

Greg in Mississippi

Everything Matters!

2 systems... Well-Tempered Refs->ET-2.5->DIY or Lounge LCR MkII phono stages

Standalone digital Sony HAP Z1-ES or SDTrans384/Soekris DAM DAC

Networked digital Zotac PI320-W2 LMS Server -> EtherRegen -> USBBridge Sig -> Katana / Ian GB / Soerkis / Buffalo-IIIPro DACs

Passive S&B TX102 TVC or ladder attenuators -> BHK-250 -> Eminent Tech LFT-VIII / IV / VI

ALL gear modified / DIY'd; cables MIT;  all supplies DIY’d or LPS-1.2s w/HUGE Ultracaps; Audio gear on DIY AC filters + PS Aud P15s; misc gear on separate AC w/filters

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It shows nicely how bad lap tops are for noise, just look at the 3M products for EMC inside a laptop. Interesting pics,  curious as to where the really low level noise if from 2-4Hz?

Despite SandyK being a bit emotional, the majority have agreed that generic computer USB outputs can be noisy, Laptops being particularly bad. I would be interested in the new generation of laptops/tablets, even less space so more compromises.

Again though, one would have thought that the DAC input should have filtering on the supply if it is designed to be USB powered.

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32 minutes ago, marce said:

It shows nicely how bad lap tops are for noise, just look at the 3M products for EMC inside a laptop. Interesting pics,  curious as to where the really low level noise if from 2-4Hz?

Despite SandyK being a bit emotional, the majority have agreed that generic computer USB outputs can be noisy, Laptops being particularly bad. I would be interested in the new generation of laptops/tablets, even less space so more compromises.

Again though, one would have thought that the DAC input should have filtering on the supply if it is designed to be USB powered.

 

Marc

 Give it a few days, and for quite a few members it will be back exactly the way it was. : You don't need better USB cables, you don't need USB widgets, you don't need low noise Linear PSUs etc., AND if there IS a problem, it is due to poor design of the USB input of the DAC !

 Are you so naïve to believe that a single post like this will change those members minds ?

All that matters according to some, is that the 1s and 0s leaving the USB port are correct.

 

Alex

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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6 hours ago, marce said:

It shows nicely how bad lap tops are for noise

 

Again though, one would have thought that the DAC input should have filtering on the supply if it is designed to be USB powered.

 

It wasn't a laptop, it was from a 2009 24" Core 2 Duo iMac running Mavericks.

 

This said, ifthe laptop is battery-powered rather than having the power cord connected, there could be a possibility that there is less 'noise'. Problem: my 2009 MBP runs El Capitan and that old M-Audio card doesn't even run on newer OS, so I haven't been able to capture that one.

 

Now, about DACs 'should have filtering': this is happening, the newer designs do have them. I was supposed to review one of the new DACs but unfortunately couldn't because of being taken up.

 

You expect things - but that means nothing in reality. Reality and your assumptions must be tested in real life. Most people aren't even thinking about this as an issue at all despite some people warning about grounding issues, leakage currents and so on.

 

How many people actually sit down to dissect a generic USB cable and see how it's made inside, vary the geometry and listen, verify how the shielding configuration is, test all combinations at the shielding / connector interface and listen and try to make sense of it.

 

Not many. Most people have a model inside their heads that goes like this: 'It's digital, as long as the bits arrive at the other end, the sound shouldn't change, why don't you capture the DAC outputs and show us.' 

Dedicated Line DSD/DXD | Audirvana+ | iFi iDSD Nano | SET Tube Amp | Totem Mites

Surround: VLC | M-Audio FastTrack Pro | Mac Opt | Panasonic SA-HE100 | Logitech Z623

DIY: SET Tube Amp | Low-Noise Linear Regulated Power Supply | USB, Power, Speaker Cables | Speaker Stands | Acoustic Panels

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6 hours ago, sandyk said:

 

Marc

 Give it a few days, and for quite a few members it will be back exactly the way it was. : You don't need better USB cables, you don't need USB widgets, you don't need low noise Linear PSUs etc., AND if there IS a problem, it is due to poor design of the USB input of the DAC !

 Are you so naïve to believe that a single post like this will change those members minds ?

All that matters according to some, is that the 1s and 0s leaving the USB port are correct.

 

Marce isn't totally guilt-free in this respect :P

Dedicated Line DSD/DXD | Audirvana+ | iFi iDSD Nano | SET Tube Amp | Totem Mites

Surround: VLC | M-Audio FastTrack Pro | Mac Opt | Panasonic SA-HE100 | Logitech Z623

DIY: SET Tube Amp | Low-Noise Linear Regulated Power Supply | USB, Power, Speaker Cables | Speaker Stands | Acoustic Panels

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13 hours ago, gstew said:

And very nice pix and process. Thanks for sharing!

 

Greg in Mississippi

 

Wish I had taken some more pictures and captures before and after a layout change.

 

Here again, 'just a layout change' right? That means just changing where the capacitor returns pre-regulator went (the overall schematics and circuit did not change).

 

Huge SQ difference.

 

What this showed me is that even at that micro level, loop areas, connections, resulting EMI/RFI, returns/'grounding' can have large effects.

 

You can have 3 different PCBs with slightly different layouts, from the same schematics giving you vastly different results.

Dedicated Line DSD/DXD | Audirvana+ | iFi iDSD Nano | SET Tube Amp | Totem Mites

Surround: VLC | M-Audio FastTrack Pro | Mac Opt | Panasonic SA-HE100 | Logitech Z623

DIY: SET Tube Amp | Low-Noise Linear Regulated Power Supply | USB, Power, Speaker Cables | Speaker Stands | Acoustic Panels

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52 minutes ago, YashN said:

 

Dedicated Line DSD/DXD | Audirvana+ | iFi iDSD Nano | SET Tube Amp | Totem Mites

Surround: VLC | M-Audio FastTrack Pro | Mac Opt | Panasonic SA-HE100 | Logitech Z623

DIY: SET Tube Amp | Low-Noise Linear Regulated Power Supply | USB, Power, Speaker Cables | Speaker Stands | Acoustic Panels

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15 minutes ago, YashN said:

Relevant: SMPS and Grounding

 

A portion of leakage currents of SMPSes can be shunted by that technique.

 

If I'm not mistaken, this is similar to what the Tripoint 'grounding' boxes are doing (albeit with some additional passive filtering and other things) because the box is indeed connected to Earth too (as opposed to the early Entreq boxes which specifically only do what they term 'signal grounding' with an external box, some additional material and not connection to Earth).

 

So I think John found the explanation of that the Tripoint does: it is shunting part of Leakage Currents to ground, allowing this diversion not to affect system SQ as much.

 

Spot on! My conclution exactly (as I've posted on another thread). I connect my JSGT to Entreq grounding box which actually sounds better than connected to the same star-earth wired PSD as my floating SMPS in my setup (floating SMPS is connected to a balanced IT with floating secondary).

Dual floats/GI/isolations is another thing that I have found improves SQ vastly everywhere I've tried it. No isolation is absolute I'll guess! ?

 

 

Auralic Aries Mini, Ariston RD40 & Mytek Brooklyn DAC system with Fostex TH900 & Gibson Les Paul 8 reference monitors.                           

Learn from the mistakes of others. You can never live long enough to do them all yourself. Graucho Marx

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3 hours ago, YashN said:

 

Marce isn't totally guilt-free in this respect :P

 

 No, but he appears to be far more open minded than most though.

We need people like Marc to use their vast experience to help further improve this area.

Perhaps your detailed results may help to at least cause a few people to investigate further themselves with their own gear, and then perhaps pass on any additional information gained ? 

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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6 minutes ago, sandyk said:

 

 No, but he appears to be far more open minded than most though.

We need people like Marc to use their vast experience to help further improve this area.

Perhaps your detailed results may help to at least cause a few people to investigate further themselves with their own gear, and then perhaps pass on any additional information gained ? 

+1 @marce is a great guy with a lot of knowledge and an open mind to unexplained things. He is a great resource here on CA IMHO. So are you @sandyk! ?

 

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Auralic Aries Mini, Ariston RD40 & Mytek Brooklyn DAC system with Fostex TH900 & Gibson Les Paul 8 reference monitors.                           

Learn from the mistakes of others. You can never live long enough to do them all yourself. Graucho Marx

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