SMPS and grounding

[mozes]

I tried grounding the Negative output of 2 Meanwells that charge 2 LPS-1s. I cut the standard dc connector and replaced them with a screw in 2.1mm male plug and connected a silver wire to the negative slot in parallel with the negative output wire that comes from the Meanwell. I used no fancy Entreq boxes, just straight to the grounding slots in 2 receptacles in a power distribution box. 

I am impressed with the new improvement that I got, I don’t know exactly what is going on. When I remove the grounding plugs, the sound goes thinner in comparison. I thought the LPS-1 is 100% isolated, so it seems that still everything matters. I am happy and thanks @JohnSwenson and everyone for the tip!

[asdf1000]

I wonder if it's to prevent the leakage currents from getting into other gear via another path, like neutral?

 

So even with the LPS-1, it shunts the Mean Well's leakage currents to ground, to prevent it from going through other loops/power supplies via other pathways? I guess the current takes the path of least resistance, which is the bare wire used with the SMPS grounding adapter, to the earthed plug? Or the iFi groundhog which does the same.

 

 

[Superdad]

Off topic and argumentative posts deleted.

Take that stuff somewhere else guys!

[sandyk]

I have an STB which is connected to my DAC via coax SPDIF , as well as via HDMI to my TV.

 I have been a little concerned that the HDMI connection to the TV is causing a shunting of all the STB's SMPS residuals by some unknown ( to me)  mechanism, especially since they are both using different mains feeds, with the possibility of a minor earth loop.

With my STB, I also have a +5V low noise Linear PSU to power the connected USB memory stick used for recording. It also uses a short modified USB cable with +5V disconnected at the STB end. This results in improved performance of recorded HD TV,  even in comparison with direct reception of the reduced bit rate .mp4 HD TV transmissions used locally.

As the STB is sitting on top of the PSU, and the PSU uses a 3 pin mains socket without the mains earth connected,  I was able to fit a banana socket to the PSU which I connected to mains earth. This enabled me to use a short connecting lead with a banana plug on one end, and an RCA plug with only the earth side connected, to connect mains earth to the 0 volts side of an unused RCA socket on the STB. 

This has resulted in a further quite noticeable improvement in Ambience and delineation of onscreen voices on many TV shows. 

As I am using a short pluggable lead, the improvement is readily verified, simply by connecting and disconnecting this additional mains earth wire.

 

Alex

 

[austinpop]

Question for @Superdad und @JohnSwenson

 

A while back I used this approach to achieve better SQ with the Meanwells powering my 3 LPS-1s:

 

 

The P5 is just AC mains, and the Dectet is just a power strip for the purposes of this discussion. Would shunting the non +ve outputs of the Meanwell to AC ground still help, or does the use of an IT achieve the same effect? Should I be plugging the yellow plug ground receptacle (as shown in the first post of this thread) into the Dectet? Or into the P5 - i.e. bypassing the IT?

 

I know it's easy to try this, but it does involve cutting off the tips of the Meanwell outputs - and we all know how painful that can be - which may impact the resale value at some point.

[d_elm]

No need to cut DC wires, use connectors as @JohnSwenson showed.  Connect three ground wires together and attach to a single AC plug ground lead.

[austinpop]

Just now, d_elm said:

No need to cut DC wires, use connectors as @JohnSwenson showed.  Connect three ground wires together and attach to a single AC plug ground lead.

 

Ah - gotcha. My brain hadn't kicked in yet. Monday morning. 

[austinpop]

A couple more questions:

 

Anyone have an Amazon link for this sucker?

 

And is that bare wire between the male and female DC terminal blocks?

[d_elm]

28 minutes ago, austinpop said:

A couple more questions:

 

Anyone have an Amazon link for this sucker?

 

And is that bare wire between the male and female DC terminal blocks?

It is 14Ga house wire.  I put 3/4" heat shrink tubing over the assembly.

[BigGuy]

35 minutes ago, austinpop said:

A couple more questions:

 

Anyone have an Amazon link for this sucker?

 

And is that bare wire between the male and female DC terminal blocks?

Its all in the terminology used to search.

 

Here is source for 3-prong plug but lots of options...

<https://www.amazon.com/HiFiKing-PU-12-Audio-Connector-Hi-End/dp/B017NCPG8I/ref=sr_1_7?s=industrial&ie=UTF8&qid=1508170787&sr=1-7&keywords=ac+plug+connectors>

 

But I bought these so I know which are ground plugs...:-D

<http://www.hardwareandtools.com/cooper-wiring-bp3867-4gn-high-visibility-plug-fluorescent-green-efda-7490.html>

 

Source for DC power blocks but there are other less expensive sources, e.g., Ebay...

<https://www.amazon.com/dp/B01J1WZENK?psc=1>

[BigGuy]

58 minutes ago, d_elm said:

It is 14Ga house wire.  I put 3/4" heat shrink tubing over the assembly.

Bare wire would be fine assuming no chance for contact between + and - since kind of PITA to strip very short lengths.

[thyname]

This is extremely difficult for me to understand. Way over my head. And I am pretty good technically, as a user.

 

So, maybe too much to ask, but it would be ideal if an extremely nice gentleman or gentlewoman can:

 

1 - Post an instruction video on how to do this

 

2 - Links to Amazon (or elsewhere) for each of the three components needed

 

Maybe just a wishful thinking from my part

[JohnSwenson]

1 hour ago, thyname said:

This is extremely difficult for me to understand. Way over my head. And I am pretty good technically, as a user.

 

So, maybe too much to ask, but it would be ideal if an extremely nice gentleman or gentlewoman can:

 

1 - Post an instruction video on how to do this

 

2 - Links to Amazon (or elsewhere) for each of the three components needed

 

Maybe just a wishful thinking from my part

If you don't want to build your own adapter you can buy the ifi groundhog, it does the same thing, but you don't have to build anything your self. It does cost $50 though.

 

John S.

[JohnSwenson]

2 hours ago, austinpop said:

A couple more questions:

 

Anyone have an Amazon link for this sucker?

 

And is that bare wire between the male and female DC terminal blocks?

The problem is there are no universal tags for this sort of thing. Cord end male plug gets some, grounded AC plug gets some, 3-pin AC plug gets some. You do NOT need an expensive audiophile plug.

 

Personally I think its best to go to a local hardware store, go to the electrical department and ask for a 3 pin AC plug, they will get you the right thing. The one shown was $3 at my local hardware store.

 

The CATV screw connect barrel plugs and jacks are best to get on amazon.

 

I just took some 14 AWG solid core wire I had in the drawer, stripped the insulation off and cut two short pieces. It doesn't have to be 14AWG anything from 18-14 will work great. Its easiest to use solid wire, you don't want to put stranded wire into the connectors, it is too easy to miss one strand which then coils around and touches the other side. You can use stranded wire if you tin the bundle first (twist the strands together then apply solder) this way you cant have an escaping strand.

 

Yep, mine was bare wire, with the large solid core wire there is no way they are going to wind up touching each other. It doesn't HAVE to be bare wire, that was just easier to do.

 

John S.

[asdf1000]

Hi @JohnSwenson

 

Earlier today, on the ultraRendu thread about grounding switches, you mentioned for the LPS-1 it's best to ground the LPS-1 output, not the Mean Well Energizer's 7.5Vdc output:

 

https://www.computeraudiophile.com/forums/topic/30376-a-novel-way-to-massively-improve-the-sq-of-computer-audio-streaming/?do=findComment&comment=730369

 

Is that the same if using and LPS-1 to power the ISO REGEN with isolation switched OFF? I should ground the LPS-1 OUTPUT - NOT the Mean Well Energizers 7.5Vdc output?

 

Cheers again

 

[asdf1000]

On 02/10/2017 at 11:11 AM, Superdad said:

On 02/10/2017 at 9:50 AM, agladstone said:

Also, if I followed this thread carefully enough, it seems like for my LPS-1 that powers my ISO Regen, I would want to have the ground wire going to the DC input of the ISO-Regen and NOT the DC input of the LPS-1, is this correct?

 

With the present topic, no, you would just ground the DC of the supply that you have feeding your LPS-1.

 

@JohnSwenson my confusion comes from the above quote - which says for this topic, you ground the LPS-1's Mean Well Energizer's DC plug, not the LPS-1's output DC plug

 

What's the reason the advice is the opposite for grounding ethernet switches.

 

Appreciated, as always

 

[rickca]

1 minute ago, Em2016 said:

 

@JohnSwenson my confusion comes from the above quote - which says for this topic, you ground the LPS-1's Mean Well Energizer's DC plug

 

 

@Superdad was talking about how to avoid dropouts when using galvanic isolation on the ISO REGEN.  That's a different goal than eliminating leakage currents which is what @JohnSwenson is addressing.  I think this is the source of the confusion.  Alex and John, please advise whether I've got this right.

[asdf1000]

2 hours ago, rickca said:

@Superdad was talking about how to avoid dropouts when using galvanic isolation on the ISO REGEN.  That's a different goal than eliminating leakage currents which is what @JohnSwenson is addressing.  I think this is the source of the confusion.  Alex and John, please advise whether I've got this right.

 

When Alex said "With the present topic, no, you would just ground the DC of the supply that you have feeding your LPS-1" I don't think that relates to dropouts of the ISO REGEN - for dropouts, you need to ground the ISO REGEN'S USB output OR the ISO REGEN's input DC plug (LPS-1's DC plug output), since both do the same thing as both connected to the same ground of the ISO REGEN.

 

Agreed though, some clarification would be appreciated. Essentially:

 

1. When is it best to ground the LPS-1's DC plug output

 

2. When is it best to ground the LPS-1's Mean Well Energizer's DC plug output

 

 

[rickca]

6 hours ago, Em2016 said:

I don't think that relates to dropouts of the ISO REGEN - for dropouts, you need to ground the ISO REGEN'S USB output OR the ISO REGEN's input DC plug (LPS-1's DC plug output), since both do the same thing as both connected to the same ground of the ISO REGEN.

Yes, you're right.  So now I share your confusion.  My apologies to @Superdad and @JohnSwenson for mucking this up further.

[asdf1000]

9 minutes ago, rickca said:

Yes, you're right.  So now I share your confusion.

 

Ha! All good. I'm just glad I'm not the only one.

[Bruce Orr]

On 9/19/2017 at 9:27 PM, JohnSwenson said:

Over the last month I have been performing extensive tests on leakage currents coming from SMPS power supplies. One of the most important results from this investigations is the makeup of this leakage current.

 

Previously my understanding was that leakage current was mainly a low frequency phenoninum, 60Hz, and its harmonics (60, 120, 180, 240 etc). My early investigations seemed to show that this was true with some high frequency components from the switching operation, but that this was fairly small in comparison to the whole. This turned out to be not true. It turns out that SMPS leakage is very hard to measure, it consists of some VERY high impedance components, on the order of 300 Mega ohms and some much lower impedance components.

 

None of the standard electronics test equipment will properly measure this, there impedance is simply too low and drastically changes the signal while trying to measure it. My only option was to build my own ultra high impedance differential probe (around 10 Giga ohms) so I can measure leakage current directly (rather than its affect on other equipment).

 

Because of this ultra high impedance it turns out leakage current can go all kinds of places you don't think about. It turns out to be extremely difficult to block using normal techniques, the blocking device has to have over a giga ohm to significantly attenuate it, this is VERY tough to achieve.

 

It turns out the best way to deal with this high impedance part is to shunt it around the audio equipment, there is a very easy way to do this, ground the negative output of the SMPS. It seems that even SMPS that include a ground pin don't actually use it for anything. This sounds too simple, but it actually works. PLEASE do not under any circumstances  attempt to modify an SMPS to do this, this is DEADLY, to NOT attempt!!!

 

Fortunately there is a real easy - inexpensive way to do this, it doesn't take any complex knowledge, I'm calling this the power supply grounding adapter, here are a couple pictures:

 

 

This consists of three items and some wire. The yellow item is a three pin AC power plug (shown is the US model), the black parts are male and female DC barrel connectors with screw connectors, no soldering necessary! Amazon has a whole bunch of places selling these for CCTV cameras. The spec is 5.5mm outside and 2.1mm inside. Most you will see will be this spec. The + of the male is wired to the + of the female and - on the male goes to - of the female. Look at the close up picture, in order for the wire to go straight across one of the connectors has to be upside down. This is extremely important to get right. You can use many different types of wire for this, I used solid core 14AWG wire with the insulation stripped off.

 

A green wire goes from the ground pin of the AC plug to the - pin of one of the connectors, strip a little off and just stick it in with the wire going between the two connectors, use a screwdriver to tighten the screws, you are done.

 

The green wire does NOT have to be a heavy duty high power wire. The SMPS are already designed to be double insulated so the AC cannot show up on the DC output, grounding it does not pose any electrical threat. I just used some nice silicon rubber wire I bought on Amazon, but really any green wire will do.

 

You plug the output of the SMPS into the "jack" side, and the "plug" side goes into where you would have plugged the SMPS. The AC plug goes into the SAME power strip or duplex outlet where you plugged in the SMPS. This is very important to properly shunt the high impedance part of the leakage current. If it goes into a different circuit you can wind up making it worse.

 

You should do this on every SMPS that is somehow electrically connected into your sound system. Some items may have different connectors such and Ethernet switches etc. There are a bunch of different adapters available that can convert the 5.5/2.1 to just about anything out there, you may need to use a pair of these.

 

You may ask "how effective IS this?" If you want to get it all you will have to use something like the LPS-1 which will get rid of it all.

Have fun,

John S.

 

 

Just received my sPS-500 with Y-cable, so appreciate all the discussion here led by John re: grounding.  intend to use it to power a Netgear C3000 router (wifi off) and switcher (JCAT-TCXO). It all seemed pretty easy to install until I got the news about grounding. I've never cut up any cable or done much DIY electronics, so am feeling a little intimidated at the moment. Easy is only after you've done it once. Some assurance and help will be much appreciated.

 

Questions/Clarification:

• I need to ground the sPS-500 power cable between it and the switch it is powering. 
• I need an additional electrical outlet for the Yellow Plug in the same socket or strip
• One end of the new grounded barrel plugs into the sPS-500 out
• The "Y" power connector inserts into the other end of the new grounded barrel
• At this point, all is good. Enhanced SQ delivered!
• Am I also hearing that even when my LPS-1 is powering an uR and IR, grounding as John has described, is a good thing to do?

 

[asdf1000]

16 hours ago, Em2016 said:

 

When Alex said "With the present topic, no, you would just ground the DC of the supply that you have feeding your LPS-1" I don't think that relates to dropouts of the ISO REGEN - for dropouts, you need to ground the ISO REGEN'S USB output OR the ISO REGEN's input DC plug (LPS-1's DC plug output), since both do the same thing as both connected to the same ground of the ISO REGEN.

 

Agreed though, some clarification would be appreciated. Essentially:

 

1. When is it best to ground the LPS-1's DC plug output

 

2. When is it best to ground the LPS-1's Mean Well Energizer's DC plug output

 

 

 

Just for anyone interested in these questions and not following the other thread, John S has answered these 2 questions (and more) in this great post here:

 

 

 

[flkin]

How would one perform the grounding if using a floating isolation transformer? There is no ground to connect to.

[Cornan]

1 minute ago, flkin said:

How would one perform the grounding if using a floating isolation transformer? There is no ground to connect to.

 

A isolation transformer, even one with floating secondary, have the safety ground intact. It is just the output that is not grounded to the secondary of the isolation transformer.

 

[jamesg11]

/& so safety cut-out required downstream of secondary ...