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

[Cornan]

https://www.silabs.com/Support%20Documents/TechnicalDocs/CMOS-Digital-Isolators-WP.pdf

 

Sent from my SM-G900F using Computer Audiophile mobile app

Thanks Middy! ?

After reading about the CMOS digital isolators I am still more confident with the analogue Vactrol VTL5C1. Firstly the CMOS requires 3,3-5v input and secondly my USB data signal is a essentially a analogue signal. It seems that the Vactrol requires much less input voltage to work...but I am still not sure if the data signal actually have enough current to power the Vactrol either. But instead of endless search for info I will just order these cheap parts, put it together and cross my fingers it will work. If I am lucky it might even improve SQ...but I'll keep my hopes for that on a pretty low level! ?

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[Cornan]

Now I have ordered the VLT5C1 linear optocouplers plus screw terminal USB plugs. I will make the experiment and report back A) if it works and B) if it improves anything.

 

Also ordered these Valab Audio ball-and-cup style feets for my speakers Valab Audio Vibration Isolation Damper Feet -- 4 Pcs to see if that will make an improvement as per YashNs suggestion. I will also practise my famous persuasion technology on my GF to get those speakers on a sand-filled floor stand as well. But that might take some time!

[YashN]

Now I have ordered the VLT5C1 linear optocouplers plus screw terminal USB plugs. I will make the experiment and report back A) if it works and B) if it improves anything.

 

They will probably work, but they will still allow noise through.

Also ordered these Valab Audio ball-and-cup style feets for my speakers Valab Audio Vibration Isolation Damper Feet -- 4 Pcs to see if that will make an improvement as per YashNs suggestion. I will also practise my famous persuasion technology on my GF to get those speakers on a sand-filled floor stand as well. But that might take some time!

 

These may offer some perceivable differences, but I don't think these are good isolation feet: the ball isn't allowed to move freely, judging from what I see in the diagrams. Therefore, it won't isolate. I don't see how the lower part of the upper portion of the feet can stay straight as well.

 

This is not the kind of thing that a ball-and-cup arrangement for vibration isolation is.

 

If you go through the Vibration Isolation thread, there are more details on how this should be set.

I have never recommended these feet for vibration isolation.

 

Furthermore, these so-called explanations on the original listing are cause for concern:

 

Vertical vibration : This is major vibration from audio gears. This isolation damper transfer vertical vibration into rotation of bearing ball. This is not a real innovation, it was used in vibration damping in many expensive precision equipments long yeas ago. Now it was introduced into audio application.

 

Horizontal vibration: It use rubber ring to absorb horizontal vibration

 

 

Both of these explanations are wrong ways to go about it!

 

This inspires 0 confidence in this product.

 

The ball should be free to move about to isolate against horizontal vibrations. An air-cushion would be used for isolation of the vertical vibrations mostly.

[Cornan]

These may offer some perceivable differences, but I don't think these are good isolation feet: the ball isn't allowed to move freely, judging from what I see in the diagrams. Therefore, it won't isolate. I don't see how the lower part of the upper portion of the feet can stay straight as well.

This is not the kind of thing that a ball-and-cup arrangement for vibration isolation is.

If you go through the Vibration Isolation thread, there are more details on how this should be set.

I have never recommended these feet for vibration isolation.

Furthermore, these so-called explanations on the original listing are cause for concern:

Both of these explanations are wrong ways to go about it!

This inspires 0 confidence in this product.

The ball should be free to move about to isolate against horizontal vibrations. An air-cushion would be used for isolation of the vertical vibrations mostly.

 

I am not following your advices by the letter on this one, just the ball-and-cup idea. The reason why I bought these is a combination of my personally very good experiances with Soundcare Superspikes plus that this is a version of ball-and-cup construction. I'll guess that the top part of the Valab feets is slightly curved and have a firm fit into the lower part plus that the rubber ring is removable, but I´ll have to check it 100% upon arrival. Since I like to experiment I will not use them as the only measure of vibration control. I will still use weight and clear quarts sand in some form since these are all things that works IME.

[Cornan]

They will probably work, but they will still allow noise through.

Good to know that it might work! I am not expecting a huge difference by this experiment initially. If it does make a positive difference it will atleast tell me that I made a correct assumption and I can focus on finding a better option for the task. Even if I end up worse I have atleast turned that stone!

[YashN]

I am not following your advices by the letter with this one, just the ball-and-cup idea.

 

This isn't what we are talking about when we said 'ball-and-cup'.

 

There is a reason the ball-and-cup, properly made, works.

 

Not everything which has a ball in it is going to be a ball-and-cup for vibration isolation.

 

There really is a need to understand the mechanism in the threads and the posts first and not jump at eBay or other sites to buy stuff which is vaguely related.

 

This won't work. If you remove the rubber ring, the ball and upper section will most probably settle in a locked position, providing even less horizontal isolation than before...

 

Again, to be really clear, this is not the "ball-and-cup idea", so stop calling it that as it will only serve to confuse other people further.

 

The proper information is in this thread:

 

http://www.computeraudiophile.com/f8-general-forum/equipment-isolation-and-vibration-damping-24805/

[Cornan]

This isn't what we are talking about when we said 'ball-and-cup'.

 

There is a reason the ball-and-cup, properly made, works.

 

Not everything which has a ball in it is going to be a ball-and-cup for vibration isolation.

 

There really is a need to understand the mechanism in the threads and the posts first and not jump at eBay or other sites to buy stuff which is vaguely related.

 

This won't work. If you remove the rubber ring, the ball and upper section will most probably settle in a locked position, providing even less horizontal isolation than before...

 

Again, to be really clear, this is not the "ball-and-cup idea", so stop calling it that as it will only serve to confuse other people further.

 

The proper information is in this thread:

 

http://www.computeraudiophile.com/f8-general-forum/equipment-isolation-and-vibration-damping-24805/

Sorry, I will not use "that" word for it!

So, reading through the link something like a caster cup with a suitable sized bearing ball would do the trick, but as I understand from JS a flat surface is even better (but more risky).

Looking at my Valab feets up-side-down

 

I´ll guess I could try to simply remove the bottom feet (ie. upper part on the picture) and the rubber ring and just use the "leg" with ball bearing faced agaist the speaker (note that it is a shallow hole). It will not be the same thing completely ofcourse due to the small size but it will atleast allow the ball to move freely on the speaker surface. The end-result will be something like this:

 

 

Do you think that will improve things in you point of view, even if it is not intirely the full picture?

[Cornan]

Hi Cornan:

My apologies. I did not mean to imply you were making such comparison. And really I think some of the Voltcrafts (having looked at interior photos of them) are built to much higher standards that many of the similarly-priced Chinese supplies in aluminum cases that pop up around here and often don't meet their own output current specs.

A quality, safe, and affordable LPS has become a rare thing in this era of SMPS. One used to be able to buy tabletop linear "bricks" from many sources.

 

I was just surprised to see the claim of galvanic isolation as it would mean they would have to electrically insulate the output regulator and/or power transistor from the heatsink and also be sure that no other parts or wiring of the board contact the case or AC safety ground. It can be done, and certainly I would think a true "lab" supply would be the sort to make "float" in this way.

 

I am crossing my fingers for you as I feel sad when manufacturers (especially of more expensive units) got to the trouble of making a very low noise supply--only to leave the nasty mains ground and its grunge with a straight path to the clean DC output.

 

Best,

--Alex C.

I received my VOLTCRAFT FPS-1134 today.

 

 

Added some Deox-it to the AHP gold fuse, installed it & grabbed my multimeter. Nada between the IEC ground pin and negative DC output (black). No beep, no value & no nothing in the continue mode. I guess that means it is properly galvanicly isolated!? I still haven't got my 4mm banana plug to DC2,1/5,5mm cable so I cannot perform a test just yet. Looking very good though!

 

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[Cornan]

I also got my second USB>DC2,1/5,5mm on the post today. So I will be able to make a trial against the following setups tomorrow:

 

1. Downhil FMC powered with unregulated 7,4-8,4v battery supply & downhill FMC powered with 5v regulated TP-Link Vivid battery.

 

2. Both downhill & uphill FMCs powered with 5v regulated TP-Link Vivid battery.

 

3. Downhill FMC powered by uPower 5v linear regulated battery & uphill powered by unregulated 7,4-8,4v battery.

 

:-)

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[Cornan]

I just realized that we haven't discussed balanced ICs so much on this thread. I have an interesting experience. I bought a 3m true balanced ICs between my primary setup to my near-field speakers a year ago and was extremely unsatisfied with the result. I decided to add the active speakers to my casual listening system with a cheap Muzu Cobblestone as source. I added a 1,5m TRS to XLR cable and also decided to add Hosa ground blockers. Wouldn't you know. The sound was better on my secondary system than on my primary system. Conclusion: whatever you have read about it. XLRs is still sensitive to length and ground interference.

 

I have just ordered a better TRS to XLR cable and are awaiting the delivery. I have also got a couple of Schuko plugs and IECs and will soon place an order of 2 x 1,5m DH-Lab silver sonic power reference to see how far I can get with my "simple" Muzo Cobblestone setup.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[YashN]

Sorry, I will not use "that" word for it!

 

OK, let's not get others, including you, confused by confusing things, so that people can get great results.

So, reading through the link something like a caster cup with a suitable sized bearing ball would do the trick, but as I understand from JS a flat surface is even better (but more risky).

 

Yes, totally flat would be theoretically ideal, but there's the practical issue that the platform may slide off the support, so your gear falls off, so in practice, we use the non-ideal but pragmatic solution of having a concave surface so that the rolling of the ball is re-centered after a while.

Do you think that will improve things in you point of view, even if it is not intirely the full picture?

No, won't work IMO: from the picture, the ball doesn't have the space to roll on the bottom. Take the time to read more of the thread so you can get a good picture, even some actual photographs of DIY or commercial solutions. If you have questions about it, ask over there, so that here we can focus on AC cleanup, Ground, etc...

 

If the ball is good, you can re-use it but you need the other things to go with it, also just 3, not 4.

[YashN]

Nada between the IEC ground pin and negative DC output (black). No beep, no value & no nothing in the continue mode. I guess that means it is properly galvanicly isolated!?

 

I think so!

[YashN]

I just realized that we haven't discussed balanced ICs so much on this thread. I have an interesting experience. I bought a 3m true balanced ICs between my primary setup to my near-field speakers a year ago and was extremely unsatisfied with the result. I decided to add the active speakers to my casual listening system with a cheap Muzu Cobblestone as source. I added a 1,5m TRS to XLR cable and also decided to add Hosa ground blockers. Wouldn't you know. The sound was better on my secondary system than on my primary system. Conclusion: whatever you have read about it. XLRs is still sensitive to length and ground interference.

 

I don't know the details of your config, for instance, whether it has a Pin 1 issue, but true-balanced with XLR sans Pin 1 issue is close to the ideal.

 

So there's a fair chance there is something odd with how the gear is configured (XLR connector at end device with chassis / grounding), or something else.

[JohnSwenson]

Guys, if you are trying to build your own USB isolator, don't even try, this is incredibly difficult to do.

 

All isolators are unidirectional, data only goes in one direction. BUT the USB bus is bidirectional, data goes both ways on the same wires. The only way to isolate this is to have two isolators, one going one way and the other going the other direction, AND switch between them depending on which way the data is going. Unfortunately there is no way to do this easily, there is no wire on the USB bus that tells you which way the data is going. The ONLY way to do this is have a full blown USB protocol engine looking at the bus and tracking exactly what it is doing so it can generate the direction signal.

 

This is NOT easy to do. There have been several attempts that have failed because they didn't properly handle the complexities of the asynchronous isochronous protocol used by USB audio. Some have succeeded in the protocol but got the timing wrong which messed up many DACs. This is a really complex task.

 

I don't want to stifle DIY attempts, but this is one you will not succeed at unless you are REALLY REALLY good at USB chip design.

 

John S.

[JohnSwenson]

Duplicate

[YashN]

Guys, if you are trying to build your own USB isolator, don't even try, this is incredibly difficult to do.

I don't want to stifle DIY attempts, but this is one you will not succeed at unless you are REALLY REALLY good at USB chip design.

 

Thanks John, yes it's definitely quite an involved thing to DIY, which is why I haven't touched this part at all.

 

The Doodlebug USB isolator, from which I took some of the post-regulator components for the Linear Regulated PSU uses an ADUM, which I know you view as less than ideal as you'd prefer GMR components here. I think this USB Isolator wouldn't work for me for the higher speed needed for some of the high-res I use though. For lower speeds, some people could get the PCB and populate it.

 

Somebody mentioned an alternative to Intona, but now I cannot recall on which forum I saw it, maybe diyaudio.

 

How's the scouting for locations and packing going?

[Cornan]

Guys, if you are trying to build your own USB isolator, don't even try, this is incredibly difficult to do.

 

All isolators are unidirectional, data only goes in one direction. BUT the USB bus is bidirectional, data goes both ways on the same wires. The only way to isolate this is to have two isolators, one going one way and the other going the other direction, AND switch between them depending on which way the data is going. Unfortunately there is no way to do this easily, there is no wire on the USB bus that tells you which way the data is going. The ONLY way to do this is have a full blown USB protocol engine looking at the bus and tracking exactly what it is doing so it can generate the direction signal.

 

This is NOT easy to do. There have been several attempts that have failed because they didn't properly handle the complexities of the asynchronous isochronous protocol used by USB audio. Some have succeeded in the protocol but got the timing wrong which messed up many DACs. This is a really complex task.

 

I don't want to stifle DIY attempts, but this is one you will not succeed at unless you are REALLY REALLY good at USB chip design.

 

John S.

Thanks John! That would give me an idea what to expect. I didn't expect much more than a fun experiment out of this project in the first place.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[marksas3]

I received my VOLTCRAFT FPS-1134 today.

 

[ATTACH]32644[/ATTACH]

[ATTACH]32645[/ATTACH]

[ATTACH]32646[/ATTACH]

[ATTACH]32647[/ATTACH]

[ATTACH]32648[/ATTACH]

[ATTACH]32649[/ATTACH]

 

Added some Deox-it to the AHP gold fuse, installed it & grabbed my multimeter. Nada between the IEC ground pin and negative DC output (black). No beep, no value & no nothing in the continue mode. I guess that means it is properly galvanicly isolated!? I still haven't got my 4mm banana plug to DC2,1/5,5mm cable so I cannot perform a test just yet. Looking very good though!

 

 

Sent from my Nexus 7 using Computer Audiophile mobile app

 

Looks great, couple of questions...is it safe to leave this running 24/7 to power a Mac Mini? Where do you buy the banana plug to 5mm barrel jack adapter?

[Cornan]

Looks great, couple of questions...is it safe to leave this running 24/7 to power a Mac Mini? Where do you buy the banana plug to 5mm barrel jack adapter?

 

Absolutely no problem to power it 24/7. Remember that this is a safety class 1 device that is probably more safe than most other power supplies (as long as it is used properly).

 

Here is the DC cable I ordered http://www.ebay.com/itm/4mm-banana-plug-to-5-5-X-2-1mm-DC-Power-Male-Plug-charger-lead-cable-for-CCTV/272519397091?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40808%26meid%3Da785b56908ec446e93f0d9ff4d1f169c%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D282197365561

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[marksas3]

Absolutely no problem to power it 24/7. Remember that this is a safety class 1 device that is probably more safe than most other power supplies (as long as it is used properly).

 

Here is the DC cable I ordered http://www.ebay.com/itm/4mm-banana-plug-to-5-5-X-2-1mm-DC-Power-Male-Plug-charger-lead-cable-for-CCTV/272519397091?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40808%26meid%3Da785b56908ec446e93f0d9ff4d1f169c%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D282197365561

 

Sent from my Nexus 7 using Computer Audiophile mobile app

 

Awesome thanks. This PSU is certainly less expensive than 'audiophile' options. This would be a great match I think for the UpTone MMK Mac Mini kit.

I found this cable also, looks like it would work...

https://www.hobbytown.com/transmitter-charge-lead-dc-plug-to-4mm-banana-plugs-by-protek-rc-ptk-5212/p14577

[Cornan]

Awesome thanks. This PSU is certainly less expensive than 'audiophile' options. This would be a great match I think for the UpTone MMK Mac Mini kit.

I found this cable also, looks like it would work...

https://www.hobbytown.com/transmitter-charge-lead-dc-plug-to-4mm-banana-plugs-by-protek-rc-ptk-5212/p14577

 

I still haven't tried it myself on my router. Still waiting for my DC cable. I cannot comment on SQ until I have tried it..but the galvanic isolation should make it a fairly good choise.

 

My Chinese DC cable is using 14awg wires. With DC cables thick gauge and short length is important factors for best SQ.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[marksas3]

I still haven't tried it myself on my router. Still waiting for my DC cable. I cannot comment on SQ until I have tried it..but the galvanic isolation should make it a fairly good choise.

 

My Chinese DC cable is using 14awg wires. With DC cables thick gauge and short length is important factors for best SQ.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

 

Yeah I just noticed that the one I posted is a thin 22awg.

As for SQ, I would think at minimum installing the MMK fan/DC kit + a decent PSU will yield good results vs the stock Mac configuration

[jabbr]

For those of you inclined to build something yourself there are two categories-- the linear regulated supplies which we discuss endlessly. I favor the Salas Shunt (eg SSLV1.1) for 8-24 v, and the Reflektor-D for digital.

 

Yet the capacitance multiplier is a much less talked about but really terrific supply that can be built for very low cost - this is perhaps the most sophisticated version: https://mrevil.asvachin.eu/amp/amp4/sub/psu2/

 

For situations where the supply is itself supplying onboard regulators it's perfect

[jabbr]

This version is a bit simpler and another reasonable option: http://www.startfetch.com/keantoken/content/Kmultiplier.php

[Cornan]

Yeah I just noticed that the one I posted is a thin 22awg.

As for SQ, I would think at minimum installing the MMK fan/DC kit + a decent PSU will yield good results vs the stock Mac configuration

 

It will surely yield improved sq vs the stock PSU.

Here is a picture of my Voltcraft adjusted to 12v.

 

 

When I get the DC cable I will post back my comments regarding SQ with Audioquest NRG-2 AC mains cable attached.

 

Sent from my Nexus 7 using Computer Audiophile mobile app