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

[YashN]

Accurately mirrors my results, particularly slightly damped HF which makes the presentation rich, warm, smooth and forgiving = very analogue in nature.

 

You should possibly now be able to increasingly enjoy the music within lesser and even bad recordings, instead of just turning them off... try a few that you previously couldn't enjoy and see if they are now enjoyable?

 

Way, way too busy doing research and design for the next levels of improvements on the Linear Regulated PSU.

 

I've already slightly tested one iteration and it was even better.

 

I can top even that actually (at least two levels above it I think).

 

To give you a feel of how the research and design is engrossing because how good the further SQ enhancements are: the Jean-Michel Jarre Oxygene 3 album I received a few days ago is still in its plastic wrap.

 

Sure, I could have ripped it and given it a listen, but I prefer spending time with the R & D as the payoff will be so much better

[YashN]

Accurately mirrors my results, particularly slightly damped HF which makes the presentation rich, warm, smooth and forgiving = very analogue in nature.

 

I agree globally with that assessment, the velvety smoothness, especially with the Elna at the output is something to be heard. In my current implementation which is one step back from the best level reached, it's a tad too rolled off for me, but this can definitely be adjusted.

[YashN]

LOL.. keep going, agree it's worth it. Just remember why you're doing it... to enjoy your music collection.

 

That's one of the reasons for sure, but just one.

 

There are many great things in life more important than audio.

[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.

[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/

[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.

[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?

[YashN]

Awesome thanks. This PSU is certainly less expensive than 'audiophile' options.

 

It's probably much less performing in that respect for the domain of application than dedicated PSUs for audiophiles. Of course, you pay for the extra R & D, components, circuitry and better SQ you get with the dedicated PSUs.

 

A Lab PSU will look to provide a stable voltage, reduce noise at the output to some extent and have additional safety circuitry. These aren't sufficient to characterise a PSU for an audiophile piece of gear, IMO.

 

None of the extra actual work to make it sound excellent for powering audiophile products will have been effected to it.

[YashN]

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

You bet, these are great things to try, especially shunts at Line Level!

 

I already tested a cap multiplier in my Linear Regulated PSU with great results. I definitely can improve on that as well.

[YashN]

This version is a bit simpler and another reasonable option: The K Multiplier

Yep, keantoken's circuit is great too.

 

I thought it would be an add-on to a reg circuit and not a stand-alone one though. I may be wrong about that.

[YashN]

Could be either depending on what is needed. Either stand alone for say an amp or right before a shunt reg to reduce impedance.

 

Good point about impedance.

 

Consider a switch or FMC or other device than can work with input between 5v and 12v -- no need or benefit for super precise regulation. Prob really need to filter out high freq hash ...

 

Certainly the approach I have been taking and getting great results with: AC Filter Box with the digital appliances like the iMac, the TV and the 4K Blu-Ray player for now, and for the DAC, using the LRP and new USB Connection.

 

Some consider the DAC as digital, but in my view, it spans both domains.

[YashN]

Some consider the DAC as digital, but in my view, it spans both domains.

 

Should have qualified my post a bit more as this should normally be 'obvious', but things aren't as simple as they may seem, especially when a DAC internally is structured as:

 

A/D --> D/A --> Digital Filter/Analogue Filter -> Analogue Pre-Amp

 

with: PDN ---- Clock ---- DAC Chip

[YashN]

Help me stop spending

The model I am buying now has a PWM fan controller and my small power requirements should keep it at minimum..

 

Superdad Alex and John S have built an alternative to the very electrically (not acoustically) noisy PWM fan controller in iMacs.

 

Does it have an effect here?

[YashN]

People constantly call 'ground' many different things.

 

Then, they also get themselves confused by the same term because it is used (just like they do) for several things, which shouldn't be called that ideally.

 

Because of this, it is easy to come to facile conclusions about the wrong thing because of textbook knowledge misapplied.

 

What should be done is call most of what is called falsely 'ground', by better terms, like 'return' and return further labelled with the origin of the current path it serves or 'reference'. That should help clear out a lot of misunderstandings.

 

Secondly, a Scientist would at least take a piece of copper, experiment with external 'grounding' (reference?) of an audio system and listen and measure and find explanations from there.

[YashN]

1 minute ago, Johnseye said:

Bottom line is that it raises the noise floor.  Perhaps some people like the sound of that.

 

http://audiosciencereview.com/forum/index.php?threads/entreq-signal-grounding-preliminary-measurements.476/

 

 

 

Pseudo-science crap: it is well-known that Amir doesn't know how to properly do measurements with the Audio Precision gear.

[YashN]

On 7/12/2017 at 1:11 PM, lmitche said:

YashN, you're back!  We have you been?

 

I'm around, just busy with projects left and right, including a lot of work in the studio, i.e. mostly with synths.

[YashN]

2 hours ago, archtype said:

 

 

I realize this thread may be on its last leg,

 

I don't think so: the subject is deep.

[YashN]

On 7/12/2017 at 0:15 PM, marce said:

Its not a hard measurement, I presume Amir has done some measurements that have upset you on a personal level judging by your willingness to attack him at every opportunity.

 

I conclude therefore that you are incapable of showing his numerous and blatant mistakes in his so-called measurements.

 

Better called mis-measurements, over at the audiosciencemockery forum. Feel free to join there, and do us all a favour too, stay there.

[YashN]

On 7/13/2017 at 4:00 AM, Fokus said:

 

Well ... Amir occasionally shows that he does not fully understand the nature of things such as FFTs, and this impacts his measurement strategies and his conclusions. That AP should better be operated by someone else.

 

Not just that: he can't even do proper measurements, just boasts about having a lot of equipment.

 

Lot of money, lot of measurement gear, still can't buy any competence in measuring and grounding properly first though.

[YashN]

On 7/12/2017 at 4:13 PM, Johnseye said:

 

Well I'll at least give him kudos for conducting the test and providing measurements.  

 

This is ridiculous.

 

What you should do instead is ask yourself whether the measurements were well-made at all.

 

Do you know?

[YashN]

On 7/27/2017 at 9:40 AM, Johnseye said:

 

I probably know as much as you whether his measurements were "well-made". I asked you to elaborate on why you called his measurements pseudo science 2 weeks ago and am still waiting for your reply.  Here it is again.

 

I'm not sure why you would call the measurements he took pseudo science, and what he did wrong.  Please elaborate.

 

I don't think you know as much as I do at all.

 

If you're convinced by blatant mis-measurements, that's your problem. If you think just by showing a graph of mis-measurements, that this is more important than actually knowing whether the measurements are well made and whether the grounding was properly done using the AP gear, that's your problem too, not mine.

 

The reasons have been discussed at length elsewhere and there's also an excellent post about how making proper measurement can be hard by iFi in this very forum.

 

mmerrill can chime in if he wants to, but I doubt you'll understand what he says either.

[YashN]

Some very cool info and links there, Mike, thanks for sharing.

 

Additionally: always cool to read John Swenson's explanations on the less obvious or more intricate phenomena in computer-audiophile land.

[YashN]

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. Meant to post this before, but was really taken up this year and besides, the evil Photobucket suddenly blocked sharing - unless you pay them a hefty fee of course... This gives an idea of what we potentially lose by direct powering our DACs (not counting DACs which are specifically designed to have as complete an isolation from the computer or such other solutions as using an NAA) form the USB port of the server Computer.

 

- Captured using my old M-Audio FastTrack Pro at the DAC outputs (iFi iDSD Nano)

- Sine 1000Hz generated by Audacity

- Spectrogram in Audacity

 

Caveats: these aren't professional by any means, but give an inkling of what each PSU is affecting and how that correlates to subjective listening at least for me and in my system. Someone with better equipment/scopes can surely do much better. It's a fun thing to do nevertheless.

 

Initially, I only did a filter for the USB power and GND leads from the computer to the DAC. However, this wasn't satisfactory: I lost a lot of dynamics, so I had to relegate that filter to another duty, but I kept the circuit at hand.

 

1. Default iMac to DAC, using a generic USB Cable:

 

 

There's a lot of things going on here... Very bad things. There ideally should be a single line at 1kHz, the original signal played by the DAC in non oversampling mode.

 

So that's what you get when you power your (my current) DAC by computer USB...

 

I set out to try and isolate the DAC from the pesky +5V and GND coming from the noise infested computer, but needed both a USB connector allowing external injection of power as well as a new PSU. So, the best thing I wanted to try is my own Linear Regulated PSU and power the DAC from that.

 

But first I had to hack the USB cable to allow the external power. Easier said than done though: while powing externally is just having two leads from the new PSU to the DAC (easy), there's handshake and any required connection back the computer to take into account. I struggled a bit with this until I found a way to filter out the GND line noise (that filter above came in handy). In some cases, if I disconnected that line, my DAC wouldn't be recognised.

 

So, USB cable hacked to allow external USB-level power, and hence the next thing I tried and which I had at hand was an iPad charger:

 

2. DAC externally powered by iPad charger with a custom short USB cable:

 

 

This already sounded better, clearer if a bit on the 'thin' side! There's still a lot of horrible things going on if you judge by the chart. The iPad charger is a compact SMPS. The better audio probably has to do with not much happening compared to #1 regarding 20Hz - nearly 100Hz because the rest does look as bad if not worse (worse especially in the 10KHz to even 29KHz region which could potentially cause all sorts of non-linearities/bad resonance at the load).

 

However, 'better' here is purely relative to example 1 above, which is a really bad system. Because just think of it: I just replaced an SMPS (computer-side) by another smaller SMPS and just the fact that the DAC is externally powered now makes sound much better. How bad must the computer-side noise be, then?

 

Now, I wanted to try a battery of sorts to power the DAC when it's not powered by its internal battery (needed say, when the internal battery has discharged too low for normal operation). So I got myself a cheap Battery Charger Pack which conveniently has a USB style output port:

 

3. DAC externally powered by cheap Battery Charger Pack:

 

 

Just be aware here that the scale on the left has changed: everything else cleared out around the 1K Sine line, so I wanted to zoom in a bit around it to see if I saw anything. Much, much better sound here, very clean. But is that all there is?

 

DIY Linear PSU to the test. Spent some time refreshing on Electronics and circuits, fished around for John's old posts on his linear PSU Design and some more inspiration around Linear Regulated PSUs circuits and posts and built a first iteration.

 

4. DAC externally powered by DIY Linear Regulated PSU (some John Swenson design in it):

 

 

Wow! Nothing prepared me for this: THE THING I noticed most and immediately was the bass content, the slam, dynamics. This sounds huge. I built the PSU as a floating design.

 

Here, if you reflect a little on what we've seen so far, this is what is lost when I'm using either the computer-side SMPS or an external SMPS: I lose a lot of the energy that should be there to reproduce the bass properly.

 

I did several other experiments, including changing capacitors post Regulator, turning the computer-side filter on and off (not a big difference, but still noticeable), combinations of the data lines shielding which showed even further improvements, etc...

 

One of the things which was especially interesting to me was finding out I could also make the DIY LInear Regulated PSU better by taking particular care of the grounding and layout.

 

In fact, check this new improved layout no components changed, just more proper thinking and design of return paths:

 

 

Again, much cleaner throughout on the graph, more good sound.

 

I am not sure what the really low level bump on the left is or whether I can also get rid of it.

 

So last year during the holidays, I had only set out to filter the direct power and GND lines from the computer, but I inadvertently re-implemented one of the computer-side USB filter devices. I also had to re-think what a USB short connector should be and got better sound this way. I also got the best sound in all these experiments with the DIY Linear Regulated PSU, in this configuration:

 

1. USB Filter Computer-side ON

2. Custom configuration with the shield for the data lines

3. DIY LInear Regulated PSU when powering and charging the DAC

 

I also re-added the AC Filter into which I plugged the iMac itself and a few other devices like the TV and the Blu-Ray player. This added yet another level of improvement. While I didn't expect it to be that much better (since I block a lot of bad influence from the computer to the DAC with both the custom connector allowing external power and the special shield configuration), but it was there and very noticeable too.

 

I've been enjoying a wicked sound here over the year, accompanying all my work through 2017.

 

It will be interesting to test a few things more in that configuration, like the copper tube external 'signal grounding'  experiment, some of the Star Quad wiring that is being discussed, further enhancements to the circuitry for the DIY PSU etc...