Wavelength Audio USB Spacelator

[CG]

I use one of these, too.  I can at least answer the powering question.

 

The instruction sheet for the USB Spacelator explains that "The power supply is sent though a linear filter, then regulated to 5V/500ma before it hits the Device USB connector."  That aligns with the specified maximum current in the USB 2.0 standard.

 

My additional two cents on the subject is that I also have an HS02.  The HS02 isn't bad, and is an improvement over no isolation.  But, to me, in my setups, the Spacelator sounds a lot better.  The HS02 came in a really nice box, though.

[CG]

I am not an expert like those guys seem to be, so it's not appropriate for me to comment on that.

[CG]

2 hours ago, Miska said:

 

This doesn't sound like the power lines would be galvanically isolated. Like they are on Intona.

 

 

That would be a misinterpretation.  

 

If you look here:  USB Spacelator Page you can see that there's a separate power connection for the device side.  If you don't apply power there, the Spacelator plain doesn't work.  

 

I'll quote from that page:

 

This is a FS/HS USB isolator and reclocker which will clean up and isolate the computer from the DEVICE end (DAC or whatever). There is a HOST port which will draw a maximum of 45ma and the DEVICE side which is powered from the wall wart supply. The wall wart supply enters the USB Spacelator and is filtered and the regulated with a ultra low noise regulator to power the DEVICE side and the VBUS/GND of the isolated DEVICE.

The power supply that comes with the product is a linear (bad word, because AC-DC power supplies are hardly linear in any way) supply that uses a step-down transformer.  Strictly speaking, since the transformer has no direct connection between the primary and secondary windings, this makes it galvanically isolated from the AC mains common mode current path.  Of course, there's some capacitance between the primary and secondary windings, which couples common mode currents proportionally to the frequency and that capacitance.

 

I don't want anybody to go away with the wrong idea here.  Not fair.

[CG]

4 hours ago, Miska said:

Now someone will need to measure a DAC with the thing and see if it makes things better or worse...

 

I'm not very motivated myself, because it needs yet another external power. I have way too many already.

 

 

I did and posted the results in another thread.

 

More power cables, or any cables, are always a nuisance.  I'm with you there.  But, little comes for free in this life.

[CG]

7 hours ago, bogi said:

Then it looks Spacelator does not implement galvanic isolation of input and output USB ports in the way how Intona and HS02 does it.

 

How do you know that?

[CG]

1 hour ago, Miska said:

Cost is about 2x compared to equivalent Intona (7054)... And still notably more than 7055-C which is USB3 (SuperSpeed) isolator.

 

 

OK.  Maybe they don't work equally.

 

One person I know owns both and prefers the Wavelength Spacelator to the Intona.  (See above for this comments.)

 

I own both an HS02 and a Spacelator.  I prefer the performance of the Spacelator.  The HS02 sits in its box.  (OT:  I wish I knew of a reasonable and reliable way to sell excess stuff like this.)

 

Everybody has their own priorities and preferences.  I am not willing to criticize anybody's personal selection.

[CG]

Jeez, is the search function broken on this website?  I'd better contact Chris.

 

I'd have to search myself.

[CG]

10 minutes ago, bogi said:

 

I wrote "it looks Spacelator does not implement galvanic isolation". Not that I know! :)

Miska previously stated in HQPlayer thread discussion that Intona and HS02 provide galvanic isolation.

And in this thread Miska wrote "This doesn't sound like the power lines would be galvanically isolated. Like they are on Intona." as reaction to "The power supply is sent though a linear filter, then regulated to 5V/500ma before it hits the Device USB connector."

Maybe Miska could explain, where he sees the difference against Intona.

 

I would suggest that you contact the manufacturers of these devices.  They would certainly know what's inside them.

[CG]

4 minutes ago, bogi said:

From the previous communication it looks that Miska does not consider USB reclocking as something what could have positive impact on sound.

 

You have to ask Miska himself about that.  I wouldn't want to second guess what he was saying or put words in his mouth.  I am sure that he has a well considered reason, though.

[CG]

3 minutes ago, bogi said:

 

If you remember some specific keywords you used in that post you can use Google search this way:
CG your keywords site:audiophilestyle.com

 

Guess what!

 

I just clicked on that self-portrait icon next to one of my posts.  It immediately brought me to a list of recent posts made by me.  There, in glorious color even, the plots showed up in the brief summary of the posts.  (I found your recent posts by clicking on your icon, too.)

[CG]

2 minutes ago, Miska said:

 

Measurement data would show how these rate, that's why I was asking about it. How much for example this makes difference to Intona, measured from DAC output.

 

 

I don't have an answer for you on that.

 

What I can say is that most of the very little measurement data I've seen published was made with an Audio Precision test system.  That's obviously good in some ways, but bad in another.  

 

AP gear is very well engineered to make measurements of the device under test under ideal conditions.  The CMRR is as good as it gets.  The AP power supply is very well isolated from the AC line.  And so on.  Any Heisenberg questions have been minimized.  

 

If you want to introduce imperfections, like how an amplifier's distortion might change when not driving a purely restive load, you have to add the imperfections yourself.  There's no standards for these, generally, and very few testers even bother.

 

So it is with a lot of the digital measurements.  When you try to replicate the environment of what a real system in a home is like, you often get flaky and unpredictable results.

 

I got especially interested in this when I bought a pretty good A-D converter for testing along with a DAC that I wanted to use as a signal source.  The A-D arrived first and I tested it with a really low distortion (like -150 dBc) oscillator that was battery powered.  With a notch filter to reduce the fundamental frequency into the A-D, indeed the measured distortion was about that.  With no notch, the worst distortion product was shown to be the third harmonic at about -135 dBc, if I remember right.  That demonstrated the limits of the A-D.  Can't much complain about that performance.

 

When the DAC arrived, I plugged it into the same test system and the measured noise floor bounced and there was crap all over the place.  I tried fiddling with various measurement software settings, the device drivers, and everything I could think of.  I was convinced the sample I had was broken and was getting ready to return it.  

 

In desperation, I tried attaching the A-D to a second, separate computer which was plugged into a different AC mains socket across the room.  So, the DAC was running on one computer generating a tone and the A-D on another measuring the output of the DAC.  The performance still was quantitatively bad but was entirely different qualitatively.  

 

Hmmm...

 

So I then tried attaching the A-D to a battery powered laptop.  I got almost exactly the same results as what was published in the DAC reviews I found online for the product I'd bought.  The crap was gone entirely.

 

Must be a common mode current loop, I thought.  When the DAC was connected back to the test system computer, adding a USB isolator fixed all of the bad performance, which mostly confirmed my thinking.

 

Now, an obvious conclusion might be that the A-D is deficient.  Well, I measured the common mode rejection at its input to be somewhat better than -60 dBc.  That's not as good as an AP test system (according to its published specs.)  But, that level of common mode performance is almost certainly better than all but a few preamps or power amplifiers that people use to play music.

 

My thinking, which everybody is welcome to disagree with, is that real systems in actual use have lots of noise currents everywhere, and a lot of it is transmitted as a common mode signal.  Improving that condition seems really desirable.  After all, I could measure it.

 

To be fair, what I measured was just a part of a system.  The computer running the software probably generated the tones and played them out from memory.  I have no idea what the analysis part of the software did in terms of toggling hardware bits on the computer board, generating noise.  

 

A music system is somewhat different in its task, for somewhat obvious reasons.  How that affects noise generation, I can only speculate.  

 

Plus, there was no preamp or power amp attached in my test.  Those would only complicate the common mode current mesh in ways that are hard to predict.

 

I suppose I could try to measure the noise currents directly with current probes, spectrum analyzers, and so on.  But, why?  I'm not selling anything.  I'm not publishing a paper.  I only do it for my own purposes.  If I come across a seemingly good solution that I like and seems to conform to some idea I have (that doesn't happen all the time...) that's good enough for me.  I'm even reluctant to share anything I might find with anybody but a couple close friends who are interested.  I don't wish to spend my hobby time in a online debate where the debate will become the thing.  I only responded here because somebody asked what I thought was a very reasonable question that I have some information about.

 

Sorry for going on like that.  

 

 

[CG]

6 minutes ago, Miska said:

 

I just perform standard set of measurements with isolator and without isolator and compare the results. Test signals are played same way as music would be played. Files just contain test signals instead of music.

 

 

Well, I'm not sure I agree entirely.

 

Test signal files tend to be short.  They get loaded into memory and get repeated.  Music files are longer.  They often get loaded from disk to memory. (Some software does allow you to load the music into memory - a sort of RAM disk)  The SSD or hard drive has different current demands, often from different regulators because of the voltages, if I recall right.  That has to change the generated noise in some way.  By how much, I can't say.  But, I have observed in two entirely distinct playback software solutions on two different computer architectures that playing from memory sounds different.  Better, to me anyway.  That suggests that something is different.  What, I don't know.  Nor have I even tried to measure that.

 

Anyway, the measurements I made were exactly as you described.  None were of an Intona product.

[CG]

1 hour ago, Miska said:

If your isolator is working as intended, any possibly generated noise has no effect whatsoever.

 

In addition, if you use a NAA, what ever you play always looks the same from NAA perspective. It is just constant network data flow headed to the DAC.

 

 

Yeah, I measured Intona. And it worked exactly as described. I've had some other USB gadgets over time which didn't...

 

 

Big if.  Nothing is perfect.  I wish that wasn't true.  Any is a very exact and absolute word and no effect whatsoever is a very exact and absolute phrase.

 

I've seen estimates that the best isolation devices, except for optical fiber which isn't used in any the devices we're discussing here, have a coupling capacitance of around 5 pF or so.  Think of what impedance that is at, say, just 1 MHz.

 

The best 50/60 Hz power transformers I've measured come in at about 45 pF or so.  Admittedly, I have not measured every available transformer.  That 5 pF for the isolator is effectively in series with the 45 pF of the power transformer for that part of the common mode current mesh.  You could use an open loop DC-DC converter to improve on that, and those transformers often are also  in the 5-10 pF coupling range.  That all helps.

 

In my (former) day job, I learned over time that even a small amount of noise will degrade mixed signal conversions.  That could come from transients on the power supply plane, common mode signals converted into differential mode signals for a bunch of reasons, and so on.  Those can quickly reduce the MER/SNR/BER pretty quickly.  Which is why most digitally encoded transmission systems employ some sort of error correction scheme.  Or, more than one.

 

Would these same effects be audible in a home audio system?  I never got involved with that, so I'd only be guessing here.  These devices aren't perfect black boxes that look nice in a block diagram.  At least, they never behave that way.

 

~~~

 

I don't know.  I don't use a NAA.  But, I certainly believe what you're saying there.  So, does that mean it's always degraded?

 

~~~

 

I believe you and you probably have measurements you are willing to share, right?  

 

~~~

 

Anyway, this has gotten way off the track of the original subject matter of this thread.  I apologize for my role in that.  As I suggested  before, I'm certainly not going to convince anybody of anything or help answer their questions.  Besides, at least in audio, whatever people like is all good.  It's a hobby.

[CG]

7 minutes ago, Miska said:

 

On my tests, Intona 7054 already cleaned up enough that all the conducted noise peaks fell below noise floor, meaning well below -150 dBFS.

 

 

How did you determine that?

 

(Note - I violated my promise to stop posting here, but I want to understand this.  So, no response from me after this.  No need to cheer.)

[CG]

19 minutes ago, Miska said:

 

By measuring? While playing test signal, everything was clean at least to -150 dBFS.

 

One of the common offenders is 8 kHz USB packet ticking. This got cleaned up as well.

 

 

With 20 ENOB, maybe, doesn't that level of measurement imply a lot of averaging?  So, for example, if any noise was more or less randomly distributed, it would show as a modest change in noise floor.  And, how do you know the A-D contribution?

 

I'm only asking to understand.  If it's above my level or a secret of some kind, no need to reply.

 

 

[CG]

24 minutes ago, Miska said:

 

I've been working professionally on DSP and signal analysis systems since early 90's. So not totally newbie on this.

 

 

Didn't suggest or imply that you were a newbie or even not an expert.

 

I will say that my own experience, not having to do with audio, has been than non-synchronous and uncorrelated imperfections tend to get lost in the noise of measurement, so to speak.  Since they tend to be random, sort of, short bursts get averaged out because they appear once during a sweep and not again for a while.

 

An example of that is watching the constellation of a QAM or ODFM signal on a spectrum analyzer.  You can occasionally see a collapse or explosion of the displayed constellation.  Since it only occurs during that one frame, it barely affects the averaged MER.   But, if you were to be keeping track of the BER, you'd see errors.  (One solution to that problem is to chart the MAX or peak level of the noise floor over a longer period in order to capture those randomized bursts.  I've seen bursts like that caused by resonances in the power distribution system that just happen to get excited by a particular code combination getting processed.  Lots of other reasons, too.)

 

The test equipment can fool you, too.  Really good test equipment puts the DUT in an ideal environment where flaws don't necessarily show up as they would in actual use cases.

 

But, this is audio.  Some aspects get judged by people listening.  Other aspects get judged by people making measurements.

[CG]

On 7/11/2023 at 2:21 PM, ittaly said:

What I find unusual is that in this AS thread, there are no formal measurements (yet) or disassembly/inside photos.

 

I have a response for this, based on my own observations and experience.  They're general observations, not directed at any one individual.

 

Measurements require test gear.  Which I happen to own.  But, I am generally loath to measure any one piece of gear for posting on the internet.

 

Here's why.

 

In order for measurements to be useful, there has to be some sort of standard.  OK, just what is that?  An Audio Precision test system?  (No - I don't own one of those.)  In this case, just what DAC should be used?

 

The AP system is very expensive and part of the reason for that is the great lengths the company goes to in order to minimize the interaction of the test system with the device under test.  Among others things, that means that the AP has superior common mode signal rejection at its analog inputs and outputs.  The power system is optimized to minimize the possibility of currents conducted through the power mains.  And so on.  There's a reason that they have the reputation they have.

 

So, in an environment like that a USB isolator may have no effect.  A USB isolator is supposed to be a remedy for the system deficiencies AP charges a lot for to minimize.

 

But, just who has a home audio system that has all the performance features of an AP test system?  I'd like to know of even one system like that.

 

And, what DAC should be used for this test?  Isn't it almost certain that different DACs will behave differently within a system?  Even the online performance tests of DACs within the high isolation of an AP test system show considerable differences between DAC samples.

 

So, what is the standard for measurement for USB isolators?  Personally, I don't want to get in the middle of unwinnable arguments like this.  More than enough people are eager to insult anybody who even suggests that a product like a USB isolator might have some audible benefit.  So, I'll steer clear.  I did offer my own view that, for me, USB isolators are a benefit in sound quality.  Earlier, I offered some examples (measurements) of why that seems to be true.  If people find those observations worthy of a further look for themselves, great.  If not, I'm OK with that as well.  In retrospect, I shouldn't have even offered those observations.

 

As for showing photos of the inside or even schematics, well, forget that one, too.

 

I recently retired from a career of designing electronic equipment and systems for the telecommunications industry.  Everything we built, no matter how simple, took resources of some kind.  In many cases, lots of resources.  The pricing of equipment is not just based on the simple bill of materials for the product.  There's development costs, warranty costs, test costs, certification costs, overhead, wages for the workers, and even some profit for the corporation.  And more.  Yeah, all of those can vary a lot based on the industry and a zillion other factors.  Even plain old greed.  I was, ahh, encouraged along the way to patent whatever could be patented.  I was also, ahh, discouraged from discussing anything with anybody - often even within the company itself - unless various non-disclosure agreements were in place.  That was all because of the value the company put on my designs.  (Other people's, too, of course.). Believe me, they didn't value me as much as they valued the designs.

 

Personally, I'm not interested in showing off what's inside somebody else's design.  They invested in it and did the work.  I know that I never was happy when I found out that a competitor had copied one of my designs and tried to sell it.  In my case, that didn't affect my pocketbook at all.  For the audio guys, it well might.  In the case of audio gear, most of the companies are small.  Maybe even just one or two employees.  Small companies selling small volumes of products have it hard enough without somebody "borrowing" the design and selling a competing product that they didn't have to invest time, money, or much in the way of resources of their own.

 

In fact, I don't even post my own DIY audio design work on the internet.  I've seen other guys who have done that, only to find that the work gets copied and sold.  OK, that stings, even if you aren't attempting to make money at all from your audio projects.  It stings because you get no credit.  You feel ripped off.

 

But, know what's even worse?  When somebody credits you for a design, but then puts their own spin on it.  Maybe it works better, maybe not.  Maybe it's not to somebody's expectations, whatever those might be.  Guess who gets the hate email or bad comments on the internet?  The original designer!  That's true even if the original designer never even saw that his or her work had been copied.  How's s/he supposed to help with that?  He or she takes the abuse without any possibility of reward or even salvation.  That's crazy.  Why volunteer for that?  The copier always seems fine taking your work and profiting from it, but not much else.

 

My last observation is that an awful lot of the people who ask for or demand measurements or an inside view of a product never offer to publish their own measurements or purchase a product to show off the inside, if they think that's an ok thing to do.  Is that fair?

 

Everybody can make their own rules for what they choose to do.  The above are mine.

 

One other thing.  I don't go through all the threads here on AS.  Indeed, I only look at small number of posts.  I don't recall many photos of circuits or much in the way of measurements.  Am I missing something?

[CG]

No kidding!  Isn't that exactly my point?  Why post measurements that will vary from system to system, suggesting to people that some product will improve or not improve their listening experience?  Is that actually useful?

 

Measurements are certainly a very valuable tool.  They'll tell you if a component works properly.  They help you refine a design by allowing you to change operating conditions and circuit details to get a result you might like.  But, they only give you an idea of how a device performs under the test conditions, which as you point out is quite variable and different from system to system.  It all only works within the context of the test conditions.

 

While those test results would be quite useful for me, in my system, that's quite different from posting the results taken from a very limited universe of audio systems and extrapolating some conclusion based on limited data points.  And, that is what is usually done on the internet, both in articles and in forums.  Repeated often enough, the conclusion becomes dogma, which is almost impossible to discuss rationally.  

 

I can point to more than one test about USB isolators published on the internet that have reached different conclusions from those you described.  So, who is right?  See my point?  Who wants to get in the middle of that?  I don't.  (Note that I am in general agreement with you about the value of a USB isolator...)

 

Anyway, that's why I don't normally post test measurements.  

 

In the past, if somebody asked whether another reader has tried a component, and I have tried it and found it useful, I occasionally posted my impression in an attempt to be helpful.  I've actually reconsidered that approach and am not going to even do that any longer.  It's actually not helpful to anybody and just provokes arguments, which also aren't helpful.

 

Besides, I was just addressing the comment somebody posed that he found it unusual that readers of this site hadn't posted test results in this AS thread and along with a tear down with photographs.  I gave my reasons why I wouldn't do either.  Nothing more.

[CG]

BTW, when I wrote "So, in an environment like that a USB isolator may have no effect"  I really should have said "So, in an environment like that a USB isolator may have little or no effect."

[CG]

12 hours ago, WEN HONG said:

The Usb Spacelator arrived after an 18-day shipping process. Just connected a Macmini M2 to the Qb9-20 and the sound impact is positive. The included linear power supply is a Chinese brand and I'm in Beijing.

 

 

 

 

 

I'm glad that it's working out for you!  Don't you love when that happens?

 

Side note...

 

I hadn't even thought about this thread since last summer, until I got a notification of Wen Hong's results in via email.

 

But, reading through it all again, something stuck out.  A number of comments were basically made along the lines of how I should measure this, and reveal that.  But, I noticed that not one other person stood up and bought a device to measure and/or tear down.  I'm not sure that many people here even have bought any form of test gear.  (I know Miska has...)  Not that anybody should be required to do either of those, at least according to me, but why are they making demands requests of others to do that for them?  So they can pick on some manufacturer?  So, they can beat up on me?  I don't get it.

[CG]

14 hours ago, skids929 said:

 

 

you keep calling it an isolator and it's not just an isolator it's a reclocker...As far as measurements go, until you have equipment that can measure how I hear and absorb, and perceive sound measurements are nothing more than a reference point. The greatest audio equipment uses the ear as a the finishing touch...There is no better measuring equipment than that. Period

 

I'm not sure where you get your information, but it is an isolator.  The upstream and downstream sides are galvanically and otherwise isolated with internal transformers in the signal paths.  This technique has been used in medical equipment for quite some time now.  Yes, there is often reclocking performed on the signals.  But, a device can do both, can't it?

 

As for the value of an isolator, it's to minimize the effects of common mode currents, primarily in the loop between the digital source and the DAC.  These currents very often cause a layer of unwanted signals and noise at the DAC output that aren't part of the original music/sound.  (Contrast that to other distortions, like harmonic distortion.)  It's like not getting to appreciate the nice rug on your floor because there's a layer of trash covering it.

 

That's where measurements come in.  How can you separate one imperfection from another otherwise?  Audio measurements are certainly not complete in any way.  So, please point me to where I ever even suggested that the human aural system is not the final and most important determinant in how an audio system sounds and is enjoyed.  I will gladly publish an apology and correction when you do.

[CG]

17 minutes ago, skids929 said:

 

 

Rationalize much? 

 

Huh?

 

I note that you've used this response in other threads in the past.

 

Perhaps it would be helpful if you explained why you think that an Intona device, a Topping HS02, the now discontinued UpTone IsoRegen, or this Wavelength USB Spacelator are not isolators.  And, why you think that doesn't matter, in your opinion.

 

As for the rest, maybe you just are looking for an argument of some kind.  Dunno.  If so, please say so and I'll just declare you the victor and I'll move on.

[CG]

4 minutes ago, skids929 said:

 

I note you've use this rationale in other threads..Congrats. I NEVER said it wasn't an isolator. re-read it maybe it will sink in. sheesh

 

Umm... How about from here:

 

"you keep calling it an isolator and it's not just an isolator it's a reclocker..."

 

OK, you say it's both.  My mistake.

 

But, then, what is your point?  There are other USB isolation devices out there that don't reclock.  They reduce that trash level covering the floor.

[CG]

So, again, what is the point you're trying to make?  That isolation doesn't matter?

 

E1DA uses this device, I believe, in their Cosmos ADCiso.  It kills the common mode noise that you can easily measure.  No reclocking whatsoever.

 

ISOUSB211 Data Sheet