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So here's the setup. I'll be comparing the TeraDak 12-Volt 10-Amp linear power supply against the stock switcher that was removed from the Mac Mini. I will also compare against a 12-Volt battery. Results will be posted later in the week.
PS Audio NuWave DAC, Mac Mini, TeraDak Power Supply, ARC VSI-60 Amp, Tannoy Definition D500 Speakers.
- iPad Visual Remote Control, Mac OS X 10.8.5, 24/96 AIFF files on Mac, Audirvana Plus: Memory Play, Exclusive access
mode, Direct mode, Integer mode, SysOptimizer.TeraDak 12-Volt 10-Amp linear power supply powering the Mac Mini. Power supply heat sinks don't even get warm
as the Mac Mini is drawing less than 9-watts while playing music. The Mac Mini case remains cold to the touch.Decided to try a 12-Volt battery on the Mini just for grins. And why not since it's so easy to do now that the Mini
requires only +12VDC for its external power source.Attached my cheap 12V 7Ah SLA battery I had lying around. Saw nearly 6-Amp peak current draw during bootup
then down to less than 9-Watts power consumption while playing music.
Here's the output of the TeraDak linear power supply under 1-Amp load measured before the additional filtering
within the Mac Mini. Noise is about 1.5 mV-pp (0.53 mVrms), not bad at all.
Here's the output of the battery under 1-Amp load. Noise is bit over 3 mVpp (1 mVrms), still not bad but not as
good as the TeraDak.
Here's what's at the output of the TeraDak power supply with the Mini turned ON*. The battery looked
pretty much the same. This is noise generated by the computer, not by the power supply itself.
*20MHz BW enabled on scope otherwise too much 'fuzz' to be viewable and time scale changed to 10mS/Div.The scope screen shots below were just added 22:25 PST. Was able to get a better periodic waveform to trigger on
when I turned on a screen saver on the Mac Mini.Transient voltage 'droop' on the TeraDak 12V linear power supply.
Transient voltage 'droop' on the 12V 7Ah SLA battery. The battery is better in this regard.
The battery appears to produce more wide band noise under a steady state DC load. However, the battery proved to be 'stiffer' in terms of transient loads.
Edits: 12/21/14 12/21/14 12/21/14 12/21/14 12/21/14Follow Ups:
It would be interesting to see what a high "C" lithium battery looks like on the scope.The "C" Rating is the maximum discharge rate of the battery.
11.1 volt 2000mAh @ 10C
2000 milliamps = 2 amps
2 Amps x 10C = 20 amps discharge rate.These little batteries are available up to 80C or more,
Only issue is they are either 11 volts or 14 volts but it would be interesting to know if they are quick enough to provide a stiffer supply.
Edits: 12/27/14
It might be interesting to try a couple different battery types, view their outputs on a scope, and maybe even place some ultracaps across them. However, beyond being more than sufficient to properly power the computer, I'm not convinced there will be an audible benefit.
It is my understanding that the true Ah capacity of a given battery will vary depending on the discharge rate. It's not a linear relationship so most SLA battery Ah ratings are normalized to C/20. In other words, if you take the manufacturers Ah rating for the battery, that is based on the Ah marking / 20. So a battery spec'd at 7-Ah is based on a discharge rate of 7A/20 or 350mA for 20 hours. But it may not deliver 7-Amperes for a full hour.
Other than the max C-Rating, how do they arrive at the Ah rating for thos lithium batteries? At what C rating is Ah determined?
"Other than the max C-Rating, how do they arrive at the Ah rating for thos lithium batteries? At what C rating is Ah determined?"
I really don't know, I presumed it was based @ or about the maximum C rating just for the fact that in application the batteries are typically run close to max.
What a weird web site. You have to order the power supply before you can find out the price. This is crazy why can't they publish the price?
I bought mine new off eBay. There are several sources that publish the price.
What do you have to do to the Mac Mini in order to bypass its internal switching power supply?
You have to remove the Mac Mini internal switching power supply and feed the Mini +12vdc directly, or through an optional filter. TeraDak and some others also provide the optional filter module. You can see the filter module in white at the link below.
Do you think the Mac Mini sounds better than using a Mac laptop?
No, I don't. If anything, the laptop on battery has the potential to sound better, depending on what 'theories' you subscribe to. ;-)
Nice exercise. But it is still......
We get it already. You are anti computer audio and prefer a turnkey black box solution.
No. I'm looking for a digital file player/streamer designed and built by audio engineers to play back bit perfect audio.
You already own one!!!
Abe, I have a question related to one of your pictures:
In the 3rd. picture -- the one with the yellow cased multi-meter -- where did you obtain the plexiglass shelf that the Mac mini is setting upon?
I've had that acrylic monitor stand for many years and I honestly don't remember where I got it. I may have purchased it off Amazon or OWC macsales.com
It's just a monitor stand, so you might find something similar via internet search.
Thanks Abe!
BTW, I found a link that you posted in another thread:
Great! That's good to know because I totally forgot where I got it. ;-)
The problem with such measurements is to come to a conclusion that relates somewhat to audio.You don't want get a better Mac Mini, first of all. I'd guess the Mini runs pretty stable.
The question is: Does the mess on the computer powerrails/ground finds its way to your DAC? Does the mess impact the DAC performance?
If so. The key question is:
What is/are the actual problem(s) of your DAC??
Edits: 12/23/14
It certainly might if 'the mess' is the data being sent to the DAC.
Agree.
The measurements on the power supply are just to check that nothing is grossly wrong. I measured for wide band noise under modest steady state 1-Amp resistive load and also measured under computer load. I wanted to 'see' what a battery would look like vs the TeraDak 'audiophile' power supply.
I'll look at the output of the DAC. And of course listen for any differences. I don't have a spectrum analyzer so the basic scope will have to do.
I also have three more 12v capable power supplies that I'll look at later just for grins:
- Bench linear power supply capable of 12v @ 10-Amp
- Bench switching Power supply capable of 12v @ 20-Amp +
- Agilent Linear Lab power supply 0 - 30v @ 5-Amp*
*This one is insufficient to boot the Mac Mini. Even though the Mini draws less than 1-Amp playing music, it peaks just over 6-Amp momentarily during the boot process causing the Agilent power supply to go into current limit protection.
Hi and first thanks a lot for the very interesting testing
You say " This is noise generated by the computer, not by the power supply itself " .. so the real problem is the computer ?
Maybe you should look at another platform if your aim is to get low noise, a very good aim of course. Noise is not music.
Just asking.
Thanks a lot again.
Kind regards,
bg
Edits: 12/23/14
The 2 are interdependent It is nasive to think or say otherwise.
Hi and i admit to be quite out of my field
But reading elsewhere i have seen that when the aim is to set up an "audiophile" pc, the off-the-shelf solution is hardly the best choice.
A MAC mini is an all purpose PC ... it must do a lot of things not only playback audio.
It is a long selection process to find the best MB, power supply, CPU, OS and so on.
I would follow that route instead of picking up a commercial unit and try to put a patch here and there.
Not all the MBs are made equal so the PSs and CPUs
For instance many off-the-shelf units come with video cards embedded
Is it needed for audio ? no. Could it give issues ? maybe.
No fan should be present in an audio pc this i have concluded recently. A passive cooling is mandatory.
Absolutely no spinning hard drive
We should limit the causes of those spikes at the beginning as long as it is possible.
For instance i like very much the PCI caps bank solution, impossible to use in this case.
To end i guess it is quite difficult to find a very good off the shelf unit for this specific purpose.
One day i will set up a specific pc for audio from components (these off the shelf of course).Just one last though ... i am still convinced that if an usb dac is very well designed and built it makes all these discussions of secondary importance and one can select the pc on the basis of its look for instance and the Mac Mini is quite fantastic on this aspect.
Nice object.
Thanks again.
Kind regards,
bg
Edits: 12/24/14 12/24/14 12/24/14 12/24/14 12/24/14
You should try to understand and accept that we are dealing with a 'system' and that the components are interdependent. To think otherwise is simply technically foolhardy and comes from what I call 'conviction' audio whereby one simply defines the dac as the unique culprit. This is convenient for vendors, as some can conveniently dismiss the influenec of components other than the ones they make and sell.
....'conviction' audio whereby one simply defines the dac as the unique culprit.
Can easily be said of those who define the PC as the unique culprit, don't you think?
And since you mentioned 'the system' wouldn't it also be reasonable that certain components in 'the system' might have a greater overall effect on the 'system sound' than another component?
Did you not see my question to you linked below?
Maybe you should look at another platform if your aim is to get low noise, a very good aim of course. Noise is not music.I don't think you understand. I don't listen to the power supply. The 'noise' is what you see on the power supply DC due to large variation in switching current demands made by the computer. Any working computer will have the same effect on the power supplies under test. If the power supplies were unable to tolerate those variations, the computer simply would not work or be unstable.
The bottom line test is, do you hear the effects of the different power supplies out the DAC and through the rest of the system when playing music.
If the concern is for that 'noise' getting back into the AC mains, that can be cured with a decent power conditioner before the power supply.... whether that power supply is a switcher or a linear supply.
The battery is completely isolated so in this case, there is no concern for that 'noise' being conducted thru the battery and into the AC mains.
Edits: 12/23/14
Hi Mr. Collins and thanks for your reply
Let me see if i understand
1) a computer is a tough load for a PS. Am i right ?
2) nevertheless it must be seen if this ps noise is in someway audible at the dac outsTherefore my question is ... why to use a pc ?
Better ... is the pc really the most sensible approach to reproduce audio ?
Maybe the "streamers party" is right
A streamer looks to me a dedicated, stripped/slimmed down pc without any other purpose. Designed exactly only for audio.
For me your measurements reinforce the streamer option.
I am completely sure that a streamer is a very easy load without all these peakes and noises.
Moreover what keeps even some cheap streamers out of the game is the lack of specific drivers for Android of many high quality usb dacs.
But this could change quite soon ... there is an unbelievable "push" towards the use of Android devices.
Thanks a lot.
Kind regards,
bg
Edits: 12/23/14 12/23/14 12/23/14 12/23/14 12/23/14 12/23/14
1) a computer is a tough load for a PS. Am i right ?
No. The computer is not a tough load for the PS at all. Millions of computers are happily working fine 24/hours a day for many years on their lazy power supplies. ;-) My computer is usually ON 24/7 with no power supply 'strain' at all.
2) nevertheless it must be seen if this ps noise is in someway audible at the dac outs.
True, but the most prominent noise in question is not PS noise.... it is computer noise on the PS DC output.
Therefore my question is ... why to use a pc ?
Flexibility is just one of many reasons.
Better ... is the pc really the most sensible approach to reproduce audio ?
Depends on what you want to accomplish. Vinyl is the most sensible approach to some. Do you like organizing thousands of heavy records on shelves in your listening room? Do you enjoy cleaning records, getting up to change sides, lifting the tonearm to jump to a different track? If so, then vinyl might be the most sensible approach for you.
Maybe the "streamers party" is right. A streamer looks to me a dedicated, stripped/slimmed down pc without any other purpose.
Yes, it is a proprietary little black box that you are mostly dependent on the manufacturer to maintain and update if they're still in business a a couple years after you bought your streamer. If technology changes rapidly and software / firmware updates are no longer sufficient, you then have an obsolete and mostly worthless little black box.... unless the manufacturer is willing to swap out parts of the innards, most likely for a fee.
Plus, you still need a PC anyway. How else would you 'rip' those files for the streamer to play? How else would you get those ripped files to disk or USB thumb drive for the streamer to play? If you used a NAS, how would you get those files to your NAS? You probably already own a perfectly capable PC. Now just add a DAC.
Designed exactly only for audio. For me your measurements reinforce the streamer option.
No they don't. Have you measured any streamers lately? How do their measurements compare? How would my measurements directly relate to audio as we hear it from our speakers? That is the question. I was not measuring 'audio' or 'noise' at the speakers.
I am completely sure that a streamer is a very easy load without all these peaks and noises.
If you're completely sure of that, and completely sure that it matters, and completely sure that the streamer option is for you, then go buy a streamer.
Moreover what keeps even some cheap streamers out of the game is the lack of specific drivers for Android of many high quality usb dacs.
But this could change quite soon ... there is an unbelievable "push" towards the use of Android devices.
If you're talking about using your Android phone or tablet as your main audio source, good luck with that. The disadvantages have been thoroughly discussed several times in other threads. Just because it CAN be done doesn't mean it makes sense and SHOULD be done. Not for me!
Hi and messages received Mr. Collins and thanks for the very thorough explanation.
Only when i was telling of audio of course i was referring mainly to digital audio (i do not listen to LP these days)
now i shut up and wait for the listening tests results
Thanks again
Kind regards,
bg
The rep rate on those transients is around 30 Hz. Wonder what is causing that? It's the same with the power supply and the battery.
Does the rep rate change with software changes? Does the same rep rate appear on the digital outs (e.g. SPDIF)? Can it be found on the analog output of a DAC? (At this stage it probably won't show up on a scope trace, but if one does an FFT on the output one might see it. One can find the right bin by taking an FFT of the power rail waveform.)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
I just happened upon that scope pattern and was able to trigger on it. There's lots more going on that I did not trigger on and did not show. I turned ON a screen saver which brought up sufficient amplitude at ~30Hz. I can't say that I can repeat it. I suspect it is just one of many 'noises'.
I told you long ago that this happens down to 10Hz, depending on the setup. There can be mutlptiple harmonics both at hf and lf, depending on the unit's current demands.
Instead, you demanded Pics which I would not supply because of the way you consistently demand 'data' from others without acquiring any of your own.
Hi,
Hmmm...
You should try a SMPS optimised for audio.
It can easily better the battery. Here for fun, something I have been working on:
This is delivering 1.25A @ 15V.
When delivering 3.75A (a bit past the official 3.5A limit) the 50Hz AC related components (100,200, 300Hz) are around doubled, rest pretty much the same.
Note the switching frequency itself is at around 3uV or -116.5dB below a 2V RMS signal - yup a PSU with better than 19 Bit equivalent HF noise...
Ciao T
At 20 bits, you are on the verge of dynamic range covering fly-farts-at-20-feet to untolerable pain. Really, what more could we need?
You should try a SMPS optimised for audio.
Do you know of one that puts out +12VDC and can source over 6 Amps? Most of the quieter supplies I've read about produce relatively low current. I don't need 6-Amps steady state but that's the approx peak current at least during bootup.
Nice plot.
Abe,
I would put a good low impedance cap across the battery. I use these types in my Crimson and they are a bit noisey. Then I would put a common mode choke then another cap right before the connector.
Really the big problem here is that the supply after it enters the computer is put into DCDC hell with probably 15 or so different power supplies. Core voltages down in the 0.9-1.1v range, then LV at 1.5-1.8, then IO at 3V3, then 5V for SATA drives (probably 4 of those), 5V for each USB, +12V for Firewire. Then a whole bunch more for display port, thunderbolt if you have it and other various peripherals.
Really we need an audiophile motherboard... oh I did do that ounce. way to expensive to make for DIY. People don't have any problem spending $1K on cables, but they would rather spend $70 on a motherboard. Oh well!
Thanks,
Gordon
J. Gordon Rankin
.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Not sure what you are referring to. Others are now making what, audiophile motherboards?
.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
I have just read a test of 4 motherboards Asus, MSI etc designed with isolated audio sections running the same Realtek onboard chip. There are measurements and SQ assessments.
The dynamic range varies by 10 dB and the output opamps range from 4580 to 1620s. All different.
Would you use motherboard onboard audio in your system?
.
s
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
The Sonre website looks a little light on details. I could be wrong but I didn't see anything to indicate that they have actually designed and manufacture their own 'audiophile computer motherboard' from scratch.
Light on details? Are you serious??? They provide more detail about the Rendu models than most manufacturers provide for 6 figure components.
"What makes the Rendu different from a computer music servers is that it's a purpose built audiophile device. The problem with computer music servers is that they all rely on mass produced mother boards designed for general purpose computing and are built to the lowest possible price point. The Rendu solves this problem by removing the consumer grade computer peripherals and switching mode power supply from the equation. The Rendu's main board has been specifically built for processing audio signals perfectly."
Of course there is no way they can fabricate their own motherboards in small quantities. You know this. However, just like companies who make very expensive speakers don't use off the shelf tweeters, they have them made to very high tolerances to their specific specifications, and are not available to others as a commercial product. Same applies here I bet.
So I'd like to see the insides of their purpose built audio device. Does it use a motherboard or not? Is it one of the standard PC form factors? Do you know? Does their website specifically say?
I talked to them via telephone.
It obviously is not common PC "form factor" as it has no video section, no PCI bus/slots, no USB bus, a custom linear PSU, no capacity to install an internal HD, or no input bus.
The pictures of the item shows all of this quite clearly.
Why do you have such a huge investment in asserting that these are all PCs, when their purpose is the anti-thesis of such: and they don't contain the actual functions of a multi-purpose PC? Are you trying to say that because they contain circuit boards, a processor chip, can access files via ethernet, and can run a limited type/amount of software, that they must somehow be (sound/behave) the same as what you can de-construct/modify a multi-purpose computer to be?
Should you not be calling your TV a computer? Should you not be calling the OPPO universal players PCs?
Why are you so angry and ferociously stubborn? You're like the climate change deniers, unreasonably rejecting plain & clear evidence.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Let's see this so called "evidence".
Experimental results required here. Analysis opinions only welcomed if data is presented along with it.
What you, Al Gore, the president, my state Governor and others seem to be missing is the fact that luckily all voters not stupid enough to blindly take a bunch of known liars for their words. All you have to do is convince the voters you aren't just making it all up. Easy huh? Show us the evidence. You're approach of calling any nonbelievers idiots without ever attempting to explain why will never work.
Evidence: Does it have a video port built into the mainboard? Yes or no?
Evidence: Does it have an USB bus? Yes or no?
Evidence: Does it have an ESATA or any HD bus? Yes or no?
Evidence: Can you load an OS on it? Yes or no?
Evidence: Can you browse the Internet? yes or no?
Evidence: There is less measured ice this year than their was 5 years ago at this same location? Yes or no?
""Experimental results required here. Analysis opinions only welcomed if data is presented along with it.""
WTF!!!!!! Nothing in the definition of the word evidence requires experimentation. Do you really need to "experiment" and try to plug in a male 15 pin "D" connector to the back of a box that has no corresponding 15 pin "D" female connector?
Hello! Why would you associate me with Al Gore, & the POTUS? Are you calling me a liar? What makes you think that I am something called a "believer?" Especially since I'm advocating the application of scientific investigation, and deduction?
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Why do you have such a huge investment in asserting that these are all PCs,
I don't.
However, there are many such 'audiophool' products disguised as dedicated audio devices that DO in fact use standard off the shelf PC motherboards. We've uncovered and discussed many such products here in the Asylum.
First.....What characterizes an "audiophool" product?
How can it be worse than a piece of Shite MAC mini, with a junk & inconsistent USB bus, crappy power supply, noisy hard drive, noisey video section, and other items like USB input buses etc etc etc...
As far as a basis for good sound, an off the shelf PC or MAC can't be any worse for audio.
I agree that a product that like auriliti DOES have an off the shelf mainboard, - but it's one of the few. And there's still no capacity to add HID devices.
MOST IMPORTANTLY, - "we" "you" have not heard ANY of these devices, - so NOTHING has been exposed.
1. There's only one device that has an "off the shelf" mainboard.
2. Besides the mainboad, their are several other elements (functions), to a PC/MAC that have a great potential to be detrimental to good sound.
3. There's no logical and reasonable basis for calling a device "audiophool" because....
A). Almost all of them are cheaper than modifying a computer, and start out with better components beyond the mainboard.
B). You, or "those" who are asserting this wholly unreasonable position HAVE NOT HEARD ANY OF THEM, - to make the assessment of "inferior audiophool" devices.
C). Sim Audio, Bryston, are in no way considered, "scam" "audiophool" companies.Finally: A mainboard doesn't make a multifunction computer, - it also requires an HID, it requires an OS, it requires the ability to install run software. My TV, CD player, Universal video/SACD player, squeezebox, & refigerator all have "mainboards." Some of those mainboards are more "computer-like" than the Sonore. The Sonore can't go out and browse the internet and download apps.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Edits: 12/26/14 12/26/14
First, I never said any of these products were scams or inferior.
My point is that many 'audiophools' somehow think that these 'dedicated' audio devices are somehow special when in fact many of them DO use standard off the shelf motherboards.... the same motherboards that many here use in their PC audio setups. Fact.
So some folks enjoy tweaking their PCs for better sound. How is that different than a manufacturer who tweaks a PC motherboard and OS for you?
And lastly, no need to go crazy ballistic.
Is that your way of dismissing my points without addressing them? I am perfectly calm about it, what specifically have i written that leads you to call my post(s) ballistic? Quote?
1. A mainboard does not a computer make.
2. Very few people are buying these products, (yet), they're too new, and there's only about 5
3 With the exception of the Sonore: The "tweaks or changes made by both are not done to the board that contains the processor.
As we've seen with transports in the past, lots matters, (the quality of the parts, wire, power supplies, case, connectors, vibration damping, simplicity of signal path. Many of these important elements are not present in a complete consumer computer, and impossible to add/change.
Especially on modern PCs, the network card, USB bus, hard drive bus, video adapter, are ALL built right in the mainboard.
I contend that an "audiophool" is a closed minded person who makes assumptions about a particular product without listening to, and/or comparing it to other items and shells out more money than they normally would.
What specific people and products are you talking about here? You started making the claim of "audiophool" products, back it up with specific products and people.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
What have I said in my previous two posts to you that are NOT true?
I don't need to address every one of your points and answer them all as we've gone through this before.
well, just about everything you said is not truei have not gone ballistic
These are blatantly not off the shelf PC mainboards
None of these devices meet the definition of audiophool devices
what have i said that isn't true?
Yes, we've been over this and you're wrong. These are facts. You haven't addressed them. You can't just change the definition of something because you personally don't happen to like one of the things. It's like trying to say that a particular chair is not a chair because you happen to not like it: all the while, someone is sitting on it. Just because most new TVs have a NIC card, can browse the Internet, has an OS that runs apps, has a mainboard that is even closer to a PCs mainboard: doesn't mean that we call it a PC.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Edits: 12/28/14 12/28/14 12/28/14
Here's a summary of what I said. What here is not true?
------------
So I'd like to see the insides of their purpose built audio device. Does it use a motherboard or not? Is it one of the standard PC form factors? Do you know? Does their website specifically say?
------------
Why do you have such a huge investment in asserting that these are all PCs
I don't.
However, there are many such 'audiophool' products disguised as dedicated audio devices that DO in fact use standard off the shelf PC motherboards. We've uncovered and discussed many such products here in the Asylum.
------------
First, I never said any of these products were scams or inferior.
My point is that many 'audiophools' somehow think that these 'dedicated' audio devices are somehow special when in fact many of them DO use standard off the shelf motherboards.... the same motherboards that many here use in their PC audio setups. Fact.
So some folks enjoy tweaking their PCs for better sound. How is that different than a manufacturer who tweaks a PC motherboard and OS for you?
And lastly, no need to go crazy ballistic.
-------------
""Does it use a motherboard or not?""
A motherboard does not necessarily a PC make.
& a motherboard is not the only component that makes a "dedicated" audiophile product. Would you like me to define that? But, - you can pretend to not know, but everyone here knows that you are yourself are building your own linear power supply, - taking some step(s) toward a dedicated audio product.
""Is it one of the standard PC form factors?""
Of course it isn't and you know it is. A rasberry Pi is not: nor is a squeezebox. The only one that it might be in this group of five is the Auriliti.
Again, if it can't function as a PC, is only used for one of the things that a PC is designed to do, (and vastly improves on that), then it can't be called a PC, - even if the mainboard was remotely similar in some limited aspects.
How does calling my responses to you qualify as going "ballistic." Because I am calling you out on being wrong, and you can't admit it, your are deflecting the subject away from the subject?
"We've uncovered and discussed many such products here in the Asylum."
That is simply not true. Cite 1.
""Does their website specifically say?""
You trust everything I write as being the absolute truth? right? (LOL)
Does Oppo's, Does Logitech's? Interesting how Oppo, Logitech, Sonos, and MSB are not called PCs either. I guess that everything with a mainboard & a NIC card is a PC? I think that I call it an amplifier: since we're being arbitrary... LOL.
""My point is that many 'audiophools' somehow think that these 'dedicated' audio devices are somehow special when in fact many of them DO use standard off the shelf motherboards.""
Who are you calling an audiophool? Please be specific. I don't know what you mean by "special," but even if they did use standard off the "shelf motherboards" the other components surrounding the motherboards make them vastly better than PCs, and are very important to SQ: especially when taken together. (Do you need me to list them, or are you forgetting about what you're doing to make your own MAC, - not a MAC: i have a feeling that I'll be waiting forever for an answer to that one).
Cherry pick time, oh: why don't you accuse me of being hysterical too, that will provide another cover to not addressing the issue at hand.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
I fundamentally made the comment that many of these so called dedicated audio products use standard off the shelf motherboards. Maybe not the products that you are so in love with, but many do. What's not true about that? I've seen many such products and we've discussed them here.
Also, if you are so vehemently anti "computer audio" why do you keep posting here? Perhaps the more generic "Digital" forum is a better place for your dedicated audio appliances?
P.S. Where do you get the idea that I'm building a linear power supply? I haven't built one for years.
""standard off the shelf motherboards"" ""What's not true about that?""They are not "off the shelf" You can't buy a rasberry Pi "off the shelf" You can't buy the modified Bryston board off the shelf, - it is custom. The Sim Audio mainboard is available off line. And, the Sonore & the Auralic Aries are mainboards custom built and not capable of being purchased by an end user.
...something that you can't seem to comprehend, a PC needs much more than a mainboard before it is considered a PC/computer.
""vehemently anti "computer audio" why do you keep posting here?""I am not vehemently anything.
Chris told us that this forum is to be used for ANY and ALL discussions on digital file playback. And, you are equally Anti-computer, as you're in the process of turning your computer into "not-a-computer."
We should also be posting here, and posts have been moved here from digital relating to Squeezeboxes, Oppo digital file playback, etc.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Edits: 12/29/14 12/29/14
They are not "off the shelf" You can't buy a rasberry Pi "off the shelf"
I bought mine off the shelf from Amazon. And I used a couple different OS's on it including OpenELEC .
You can't buy the modified Bryston board off the shelf, - it is custom. The Sim Audio mainboard is available off line. And, the Sonore & the Auralic Aries are mainboards custom built and not capable of being purchased by an end user.
So? Did I say they were? No, I said many such products DO use off the shelf motherboards. Is that incorrect?
...a PC needs much more than a mainboard before it is considered a PC/computer.
I'm not arguing that point. Where did I say anything contrary to that?
We may have different distinctions between off the shelf/and PC mainboards.We have already shown that the Rasberry PI is so difficult to use a PC, - that we might as well say that it can't.
The Razberry Pi is a speciality audio USB mainboard that a consumer can buy.If you call that audio board purchase "off the shelf" I'll be happy to concede that good point.
The other "off the shelf" mainboard which is a better example actually, -is the Auraliti: that has a video card, NIC, card, hard drive, runs Linux.
The Bryston, Sonore, Aries, Squeezebox, streamers (mainboards) can't be bought by the consumer.....
Cheers,
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Edits: 12/29/14 12/29/14
Is this an audiophile product?
Do you have any thought of your own? Are you willing to examine evidence that leads to reasonable deductions based on its veracity?
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
I asked you a simple question....
Either yes...? or no...? Do you have an answer?
You comment makes no sense at all.
I asked two questions.
Your question made no sense at all.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Then it shows your real intent. Have fun... smh Do not have time for bull shit... sorry.
for bullshit, - why did you post off topic?
Or is it just that you don't like having your own crap thrown back at you?
To start a new subject: create a new post by selecting the Post Message button.I don't have time, sorry....
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Edits: 01/07/15 01/07/15
Exactly on topic. Some keep talking about motherboards and their pedigree and how t relates to sound quality.... The board in the PogoPlug is being used in highly touted streamer.
Everything is not as simple as it seems. You can often put a pedestrian item in a pretty box, slap a big name on it and everyone goes nuts! Like ST who loves the Bryston stuff. I actually never heard a Bryston product that sounded that great IMO. And that goes back to the 70s. The amps were always dry and two dimensional to me. I still often get that feel from their stuff. YMMV...
This discussion was about 2 things: which I can't see how could possibly be muddled.1. Does the Sonore Rendu use a custom built mainboard from Switzerland that is designed only around playing back digital files?, (streaming from a NAS).
(The answer to that is an indisputable yes: for the reasons cited, & what the manufacturer told me: why would he lie when one can clearly see it)?Does it sound better because of it? I hope to know soon.
2. Gordon said that he thought about building an "audiophile" mainboard but he didn't think that he'd get enough interest. I speculated that because the Sonore was a custom built mainboard that only had 1 or 2 things in common with a PC: (no USB bus, no ESATA or HD bus, no I/O capabilities, no video, no PCI, etc), and the fact that the manufacturer told me about the other aspects/parts, (linear PSU, internal damping, connector quality, processor topology, proprietary SPDIF as the only output, etc) that this was more in line with what Gordon was talking about.
The Apple TV, and the Squeezebox, and the Sonore, all are streamers. They have more in common with each other, (and an Oppo), than they do with a typical MAC or PC computer.
I do not know if I would call the PogoPlug an audiophile device. I would probably say no, because its main purpose: it does not have many of the elements required to make it a high performance audio playback device.
I did not know that it had a board in it that was common to a streamer. I would call the SBT an audiophile device because it (playback) is improved considerably by using the digital out, using an aftermarket PSU, defeating the screen, & utilizing a NAS, instead of an USB HD.
IMO, - the Apple TV is not. But the Sonore has more in common with the Squeezebox than it does with a PC. That's one of the reasons why the manufacturer CALLS the device a streamer instead of a computer.
""You can often put a pedestrian item in a pretty box, slap a big name on it and everyone goes nuts!""
I believe that that may be true but not "often:" - as it gets found out quickly enough, and if it doesn't perform better, the item gets exposed and will quickly be gone: (it happens more often in the mid-end, and low-end were less attention is paid). In Bryston's case, - the mainboard certainly is "closer" to an off the shelf product: but it's still a custom board, and we know that things like the power supply, connector quality, wiring to the connectors count for a lot.
That being said, I share your opinion of Bryston as a company, and although I disagree a little, - (I've heard some very good sounding high-current, amps from them), - I am with you.Earlier in this thread, it was nice to get some corroboration from Gordon, that philosophically, a high performance digital playback device/transport is "better" when it has those same HARDWARE elements as other good high performance audio devices do: a very good PSU, very good connectors, removal of superfluous parts from the signal path, damping, etc. With a streamer, one still needs a processor, and therefore a mainboard: the more that you can move that board away from being multi-dimensional, the better that is going to sound. I wonder if someone will design, & somehow implement a processor without charge pumps. That will be one of the next big steps.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Edits: 01/07/15 01/07/15
"You can't buy a rasberry Pi "off the shelf"
I have. You can.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
There may be differing definitions of "audiophool" in play in this thread. Hardcore objectivists have one definition, hard core subjectivists have another. There are also "fence straddlers" who use various definitions according to situation. If a fence straddler is promoting an idea or peddling a product, he will adjust his argumentation according to whether the "mark" is a subjectivist or an objectivist.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
shot down pretty quickly around here, and in IRL. "Audiophool" companies get exposed quickly, and are eliminated rather quickly.
The fact that you are not capable of citing any specific examples, also lends credence to the above.
Traditionally, superior audio playback has been exclusively hardware driven. Computer engineers, and computer manufacturers and designers have been varied in their goal of building multifunction devices that integrate both hardware, and software in order perform many functions. For this, and other reasons, computers have always sucked at superior audio playback.
I am happy to see companies like Bryston & Sim Audio, APL, and Sonore turn their attention toward digital file playback client devices: bringing to the table much needed expertise in that area.
I think that it is very, very, foolish for someone to refer to Sim Audio as a company who makes "audiophool" products, and/or any of their products.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
I choose not to cite products and companies. Most of the information that I have is second hand and I'm not going to say bad things that hurt people without first hand knowledge. I have no problem badmouthing products based on public marketing information and I have done so on many occasions. Another reason not to be specific is that, in some cases, it would amount to personal attacks and that is not allowed according to forum rules. I am not going to be baited or entrapped into potential lawsuits, etc...
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
so on other words, I'm right and it doesn't happen...
Personal attacks and legal action aren't the conclusion of repeating examples of something that has already transpired, as you cannot be held liable for just repeating 'old news.'
And of course, none of the 5 products in question could possibly have anything remotely applicable.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
OK then, take the 'audiophool' word out of picture since it's not what is in question here.
Yes, this is the way I see it.
examined?
At least a couple of these 4 or 5 products have no USB bus.
Can you name one multipurpose computer's mainboard available today that has no USB bus?
The NIC card used to only be available as a separate bus card. I wonder if an old AT mainboard from 1995 might not make for a better transport.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
The classic example of an "audiophool" product is a repackage job with a new case, new brand name and new high price but the same old, same old innards. There have also been high priced cable "filters" that when torn down are shown to have encapsulated "blobs" which turn out to be nothing but some wires going straight through, etc... Then there is the high end marketing literature which makes pseudo-technical claims that can not possibly be true, e.g. they violate the laws of physics. In the past I have linked to some of this BS and have done a little deconstruction of the offending lies.
Depending on which circles one travels one may get a different perspective as to the fraction of salesmen, dealers, and high end manufacturers who are scam artists and those that are merely struggling small businessmen. There are crooks and scam artists in all lines of business, but they seem to concentrate most in areas where the consumers are well heeled and not technically knowledgeable and where product performance tends to be highly subjective. In other fields the customers are highly technical and value conscious and product performance may be highly objective, e.g. an airplane crashes and people die if the design is poor, making BS designs and literature less likely.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
1 or 2 DACs, (Lexicon), and a couple of cables.
This just doesn't happen in the high end, and the perpetrators are quickly exposed.
It does happen more with "bigger" low fi, & mid-end corporations.
And, the electronics industry, especially the high end, is so much better than other industries. Jewelry, hand bags, RVs. It exists everywhere and is much worse, (in everything and everywhere, that the consumer, and reviewers, don't research very well).
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
arguing with these phools.
,
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
It would be interesting to see one of these stripped down and evaluated for design, component and build quality. It would also be interesting to see various noise measurements. Without some of this information there's no way to know if this is more than marketing smoke.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
As it goes, - it is incredibly better, rich with detail, and good technical information compared to just about any other industry.
When comparisons are done, - the high end stands out as exemplary...
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Let's not get hysterical. Sonore is basically a two man operation. They place no space ads, they have had no reviews done that I know of outside of Computer Audiophile, and I can tell you first hand the build quality is phenomenal, and it is one of the two best digital front ends I have ever heard, the other being the Bryston BDP-2.There margin absolutely fair considering what they put into the design. The Rendu is $1400, and the Signature Rendu is $2900.
Edits: 12/24/14
Pity they don't do 230V 50Hz.
Many PC inmates have tried to improve MB and SPDIF performance here. I know I have. Conviction computer audio audio practitioners don't like it.
Some MAC inmates started with software player suites costing $1500 to improve sound. For sevral years some of these have pooh-poohed hardware improvements. They are still going on about usb power issues and Thunderbolt connections for audio files.
One poster wants to see pictures and another wants someone else to strip down a Sonore.
Sad but Merry Xmas.
"....Conviction computer audio audio practitioners don't like it."
lol. I'm not sure if I got the exact meaning on that, but maybe you're some kind of under appreciated computer audio revolutionary before his time.
you don't know what I am saying, and you should if you'd understood my exchanges with others, then why are you commenting? Hot air?!
Conviction audio is the phrase for those who have decided what governs sound quality and will query as potentially wrong any other factors that may be proposed on the basis of sound technical reasoning or extended listening experience with really high quality systems.
I would classify you as one of them.
Yes, the lengths some will go to and the money some will spend to try to mold a POS consumer computer Into a high grade file playback system is amazing.Power supplies, software, tranquility bases, power conditioners, the list go s on.
You may want to drop a note to Sonore and see if they do 230. I was told they have shipped units to Europe.
P.S. I see 220V is an option.
Edits: 12/24/14
propagated in order to overly praise the personal computer, while at the same time running down "high end audio" manufacturing. It's fascinating that these same (unreasonable) criticisms are not levied upon amplifiers, speakers, turntables, & (especially) CD players.
Especially when DIY destructions of commercial computers are SOOOOO expensive and fraught with many challenges & issues with complex interactions, & difficulties in identifying priority of what should be modified.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
It is because as I have stated before..there is no destination for the PC/MAC crowd. Their pain is their pleasure. The wack a mole approach is beautiful agony.
Why "settle" for a purpose built for audio device, which solves many of the problems of the computer audio chain, for as you say, far fewer dollars in the end, and have spare time to cultivate, manage, and listen to your digital music collection when you can obsess over power supplies, USB ports, McSoftware, and other distractions?
Easy answer on why the same venom is not hurled at speakers, CD players, and amps. You CAN buy an off the shelf computer, run iTunes, and connect the thin to a USB DAC and get passable sound.
To "roll your own" with speakers requires quite a bit of skill, and decent layout on parts. With amps and disc players, good capacitors and resistors, cases, and transports are not cheap by any standard and the skill to the make all these parts work together is not to be underestimated.
.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
The Tranquility Base and power conditioner would benefit the Sonore as well. I'm not in either camp as both computers and dedicated servers get the job done. But a dedicated server well done has some advantages.
I have been busy submitting my next review on the Atmosphere. A very unique product that will drive the Hydrogen Audio crowd nuts.
Merry Christmas to all of my friends here at AA.
it has no capacity to store and deliver files, and there's no way that it can modified to do so.
It is a digital file transport/player.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
.
There are different types of "servers". To be a "file server" one needs to store and retrieve files. There are "name servers" that perform name to address translation. There are "DHCP servers" that manage LAN addresses. Way back when there used to be "terminal servers" that interfaced character terminals to local area networks, etc...
A server is a running instance of an application (software) capable of accepting requests from the client and giving responses accordingly. Servers can run on any computer including dedicated computers, which individually are also often referred to as "the server". In many cases, a computer can provide several services and have several servers running. The advantage of running servers on a dedicated computer is security. For this reason most of the servers are daemon processes and designed in that they can be run on specific computer(s).
Servers operate within a client-server architecture. Servers are computer programs running to serve the requests of other programs, the clients. Thus, the server performs some tasks on behalf of clients. It facilitates the clients to share data, information or any hardware and software resources.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Thanks Tony. Some of our friends here are, well.....
Of course none of these five transports under discussion are servers.
Not sure why Tony is bothering, or you're piling on.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
"Not sure why Tony is bothering, or you're piling on.""There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Edits: 12/29/14
.
"Asylums with doors open wide,
Where people had paid to see inside,
For entertainment they watch his body twist
Behind his eyes he says, 'I still exist.'"
Merc, I always appreciate your even handedness.
Ah, the Atmosphere...heheh..Peter Brueniger has done a video on his website with it and that has caused quite a stir....good luck!!
I have been saying this for a couple of years.
In the abscence of an audio MB, one can choose to silence as many voltage rails as possible within the computer. This is difficult with a laptop or a mini of any kind.
Believe it or not, powering a music data ssd independently with low impedance decoupling can change SQ significantly. John Swenson has also posted similar remarks elsewhere.
I have already said that a battery should never be used without decoupling. In his case I would stick 10 000 uF in parallel with lower impedance bypasses on and look for changes in both transient responses and SQ.
Yes we all know that Fred has already tried everything at least a couple years before anyone else has thought of it. You da Man!
Gordon,Are you talking about a pi network filter? Might be fun to try.
With the very low voltages and extremely high currents from onboard DC-DC converters (that intelligently vary voltage on demand), they would be nearly impossible to replace with linear equivalents on an off-the-shelf motherboard.
What I am not able to do very easily, is probe at the output of the filter module that was installed in the computer in place of the SMPS.
Edits: 12/22/14
One would not need such stuff.
The load would be, after turn on, pretty constant so no need for that kind of current delivery. I am assuming a board only for audio - no internet connection, printers, simple graphics, nothing but what is needed for playback.
The A123 18650 batteries can supply great wallops of current if required and faster than any Dc-Dc converter if these were utilized instead of any regulator. Instead using a regulator "before" the battery as a charger that only charges to the voltage needed.
One of these days someone will offer such a thing and it will be expensive but there is no doubt what we pay for mass market motherboards is a rather extraordinary bargain BUT you get what you pay for.
If one could get a reliable schematic, not a block diagram, of a motherboard with parts identified one could probably come up with something good. As it is one would probably destroy a few figuring out what does what.
The A123 18650 batteries can supply great wallops of current if required and faster than any Dc-Dc converter if these were utilized instead of any regulator. Instead using a regulator "before" the battery as a charger that only charges to the voltage needed.
Do you have any evidence to support your claim above? I'm sure they provide 'great wollops of current' but can you point to any measurements showing transient response of these batteries under computer load, vs the best linear power supplies or switching power supplies?
Do a bit of research. You can start a car with them.
Edits: 12/24/14
So if a battery starts a car, that makes it especially well suited for a computer music server?
Yes this is correct. The ability to start a car is directly related to sound quality.
Merry Christmas...
The battery in this thing must be even better as it not only starts it up, it actually propels the vehicle.
Merry Christmas
You should never use a battery without additional decoupling.
Why? Find out for yourself in some fast track learning to use power supplies properly.
If using SLAs a good idea, but if using something like the A123 18650 not needed and disadvantageous for sound quality.
Have you fooled yourself into thinking you know what you're talking about?There IS decoupling within the filter module installed inside the Mac Mini. Additionally, most every digital design includes local decoupling at the Vcc input of the digital device.
Edits: 12/21/14
If you refuse to read and learn, that's your problem.
Grow up
I do read and learn, but I choose my mentors carefully. Don't flatter yourself. It's not you.
Good luck!
I am betting $5 on the battery... :) Although I would prefer 18AH.
Your last plot shows exactly what I have been talking about. The power is drooping with HF current transients. A faster responding regulator is needed to eliminate these droops.
Right. But all that is shown is the effct on the power supply.
It is what happens within the computer power and data rails that is important.
An expensive way to show scope shots which Tony Lauck would sure like, but without indications of what happens in the sub lf and high hf ranges in the MB power rails, so what?
But how do you know that these 'droops' are detrimental ?And remember, those measurements were taken before the additional filtering module installed within the Mac Mini. And another thing, decoupling caps right at the Vcc source pin to a component tend to help with those fast 'droops'. There are several such caps in most digital designs.
I'm not saying that a 'faster' regulator won't improve the screen shot but how important it might be is another question.
Edit: I just posted two more scope screen shots and it appears that the battery actually has better transient regulation, although it has more wide band noise under steady state DC load. Pick you poison. ;-)
Edits: 12/21/14
The only way I know is by anecdotal evidence, my ears.Decoupling caps should eliminate these HF droops, but they didn't in this case. If the decoupling is done right, the power supply only sees lower frequency current transients. The voltage droops on the power only get worse as the get to the loads, not better.
Your battery is better than your linear, but that just says that your linear is not very good. I have compared several LI battery supplies with ultracaps on the output to the linear I use. No contest. The fast linear wins every time.
Edits: 12/23/14
I have compared several LI battery supplies with ultracaps on the output to the linear I use. No contest. The fast linear wins every time.
I'm not sure how much help the ultracaps should be with higher frequency transients. Much smaller value caps in parallel might actually do better. I'm thinking of the parasitic inductance of the larger caps having a cancelling effect on it's effectiveness at higher frequencies. As you should know, a bypass capacitor becomes more inductive at higher freqs where even lead lengths, as short as they may be, become a factor.
Do you know of an extremely 'fast' 12V linear power supply that can source upwards of 6 to 8 Amps on peaks? I know that the Belleson local regulators are good for only 2-Amps or so, so they don't qualify for my application.
What I don't get is why the concern about ultra fast responding power supplies being good despite the inductance of the cabling vs. well bypassed stiff batteries being bad because of the inductance of the cabling.
It makes no sense as described. There has to be something else going on.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Nothing else going on. The speed makes a BIG difference. Once you hear it, you are a believer.
It comes down to the undesired inductive reactance in the capacitor design, capacitor leads, and the power supply DC cables having a cancelling effect on the desired capacitive reactance as the frequency goes up.
In a bypass capacitor, you want a low resistance (reactance actually because we're talking AC) path to ground for the high frequency noise.
In other words, a perfect capacitor will have capacitive reactance only, but that is not the case in the real world. The capacitor is more correctly represented as having series resistance and series inductance along with it's capacitance.
Capacitive reactance is inversely proportional to frequency so as frequency goes up, the reactance goes down, making for an easier path for bypassing high frequency noise (to ground).... but, inductive reactance goes up with frequency cancelling the effectiveness of the bypass capacitor at higher frequencies.
How do you accommodate for that? Inductance in parallel goes down in value so to reduce the effects of inductive reactance in the capacitors, you can wire them in parallel. That's why you often see smaller value capacitors wired in parallel with larger capacitors.... and depending on the circuit needs, you might see several very small value capacitors wired in parallel rather than using just one very large capacitor. As you wire the capacitors in parallel, their capacitance goes up AND the total series inductance goes down. The effects of inductive reactance is reduced.
It's also worth noting that when someone speaks of impedance, impedance is comprised of resistance, capacitive reactance, and inductive reactance.
Google Electrical Reactance and separately Google Impedance.
While it might be fun to 'look at' the output of various power supplies and compare their ripple, wide band noise, and transient response, but beyond being sufficient to power the computer, does it matter much?
Personally, I would be more concerned with the power supply in the DAC and more so for the DAC's analog section.
Since my computer is now set up to accept 12VDC, it will be pretty easy to try various 12V power sources on it and listen. I have a couple linear power supplies, a couple switchers, and some batteries.
Quite right. Real Capacitors are far from the ideal text-book models. Only the most expensive Teflon and paper-oils even come close, and these are usually too large to be practical for power decoupling.
Abe - putting small value decoupling caps at the power supply output does not have much effect, because of the inductance of the cabling to the load. I have some in there, but only for noise filtering of the power supply itself, not for load regulation. The ultracaps do help with medium frequency transients. They have very low ESR.
The best fast linear supply is the paulhynesdesign.com SR5-12 or SR7-12, 5 amps and 7 amps respectively.
"But how do you know that these 'droops' are detrimental ?"The circuits that the power rail is feeding will have some inherent noise rejecting character. The key to success is understanding this character, what the supply can deliver, and how the resulting performance due to interaction of power supply and the load circuit systems compare with required performance. It's a multivariable equation at least.
"And remember, those measurements were taken before the additional filtering module installed within the Mac Mini. And another thing, decoupling caps right at the Vcc source pin to a component tend to help with those fast 'droops'. There are several such caps in most digital designs."
It's true, for differential noise measurements like this you definitely have to measure right at the load to get a realistic idea of what is truly going on where it counts. Measuring upstream of the filtering will tell you very little about the power quality as seen by the load.
Though most audio gear these days, depending on application of course, is pretty awesome at rejecting differential noise but much less effective at rejecting common mode noise which is coincidentally cropping up more regularly.
Less talked about and less well spec'd on power supply equipment is the common mode noise performance on the outputs with respect to earth referencing as most common audio equipment uses. Getting common mode noise way down in earth referenced audio gear power supplies is critical. The humongous problem here is testing gear for doing proper evaluation at an audiophile level is going to cost a fortune. Your 8 bit scopes and high end fluke dmm's just wont have what it takes to see -120dB throughout the audio band and a preferably a reasonable bit beyond. A good audio adc could probably be helpful fur the lower frequencies but what about the 200kHz and up? the answer is $$$$$ gear I can't afford. Even my work won't buy that kind of stuff. It's specialty gear and gonna cost ya.
Edits: 12/23/14
I mostly agree with you. But as I mentioned to fmak (who can't seem to understand), my measurements are part of a preliminary functional test, i.e. does it appear within reason and does it work?
It's true, for differential noise measurements like this you definitely have to measure right at the load to get a realistic idea of what is truly going on where it counts. Measuring upstream of the filtering will tell you very little about the power quality as seen by the load.
Absolutely! With hundreds of individual 'load points' (Vcc pins) to test within the computer, and the thousands of variables which can affect the results, we can only assume that the power at each 'load point' is sufficient for proper operation.
On a larger scale, I don't own a high-end spectrum analyzer to view the end result at the output of the external DAC or power amp. There are very few here who do. At least one manufacturer has posted a screen shot from an Audio Precision analyzer.
"Absolutely! With hundreds of individual 'load points' (Vcc pins) to test within the computer, and the thousands of variables which can affect the results, we can only assume that the power at each 'load point' is sufficient for proper operation."
There are billions of load points in a computer, but most of them are inside the chips and hence inaccessible without very specialized equipment. The real issue is the definition "proper operation".
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
"The real issue is the definition "proper operation"."
Who else would define it besides the component manufacturer? If a manufacturer doesn't supply the info good designers need the good designers won't use their stuff.
"The real issue is the definition'proper operation'."Who else would define it besides the component manufacturer? If a manufacturer doesn't supply the info good designers need the good designers won't use their stuff.
Not correct. The proper operation of the chip according to the chip manufacturer does not necessarily imply proper operation of the motherboard according to the computer system manufacturer. The proper operation of the computer system according to the computer system manufacturer does not imply proper operation of the audio playback chain, according to the audiophile who assembled the playback chain.
If there were complete and accurate engineering specifications at each level and designs used subsystem components in accordance with these specifications, then these problems would not exist, or at the least, it would be possible to identify a particular organization or person who screwed up. However, this is not "real world". This is a particular problem when a digital computer system is used as part of an audio chain that has inadequate isolation from digital noise. Here, there are no specs whatsoever, e.g. there is no DAC on the marketplace that quotes isolation from power noise or digital interconnect noise. Indeed, there is no standard or even widely known method of measuring the impact of this noise on the audio output from the DAC. There are no known engineering methods of correlating measurements with sound quality.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Edits: 12/26/14
"Not correct. "
Sure it is. At each level of system complexity you get the choice of going integrated or piecing together discretes of your own choosing. Going integrated allows one the luxury of leaving the worrying up to the manufacturers. Limiting your choices to what has been integrated and made commercially available obviously has it's limitations as well. pick your poison.
But for practical reasons we can't get to the 'load points' within a chip so that's why I reduced the count down to hundreds. ;-)
Since we're talking about a computer, and I was talking about preliminary functional tests.... The fact that the computer boots up on the various power supplies and is working as a computer should and like it did before, that would be my definition for 'proper operation'.
You don't need an 'audiophile' power supply to make a computer operate properly.
there is no point in any tests, preliminary or otherwise, if you don't carry out the preliminary setup correctly. This is the first mandatory step towards any credible test or meaurement.
You appear to be repeating yourself at every opportunity that my setup was not correct for the preliminary functional tests that I was performing. So please explain what was not correct for these specific tests.
This shows that you don't know what you are saying or doing.
Go away Fred, you're making an ass of yourself.
the ass that doesn't know what he is doing?
.
Look forward to the results.
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