The Importance of Power Supplies Generally

[sdolezalek]

There has been a lot written in various threads about using the best linear power supplies with all sorts of electronics. Really good power supplies for devices like the microRendu cost more than $1000. If that is what makes a microRendu sing, what percentage of the cost of other audio equipment is (or should) the power supply be?

 

Put differently, are we overemphasizing the quality of LPS for our small add-on devices or are we just discovering how important power supplies might be in all of our electronics? Obviously, in a $1000 DAC you probably won't have a $1000 power supply inside.

 

Similarly, if we really need $1000 power supplies for our PC, gateway, NAS, switch, NAA, USB reclocker, DAC, etc. that's a lot of money on just power supplies.

 

Thoughts?

[sandyk]

Put differently, are we overemphasizing the quality of LPS for our small add-on devices or are we just discovering how important power supplies might be in all of our electronics?

 

No, we aren't overemphasizing the importance of power supplies in general.

However, with the computer it is possible to get markedly improved results by further cleaning up the internal SMPS supply to the peripheral devices such as the Optical device and internal SSDs, WITHOUT replacing the SMPS with an expensive Linear PSU.

 

Alex

[pooger]

Since add on power supplies are almost always small production runs, there is very little economy of scale, so they appear to cost more than most hi fi gear. But also, power supply parts tend to be the most expensive components in a given piece of gear. (Of course there are exception like large arrays of laser trimmed resistors, etc.)

 

most mods to analog gear have been power supply mods, from simple capacitor bypasses to complete reworkings. Nothing new about the concepts; many Audio Amateur articles used to be on just this, back in the 80s.

 

I think what has been a surprise was the effect that clean supplies have on digital circuits. In my home built stereo, the power supplies seem to eat up about 80% of the real estate, and maybe close to that of the budget.

[Middy]

It is a valid point and I think it ties in with the notion of Diminishing Returns....

On CA there is a drive to get the best out off the kit. As people rightly say.. power matters but at what cost....

I have no doubt John's JS2 is the psu to buy but I had to justify an Sbooster and DC PURIFIER.

May be we need a chart of benefit V cost as a basic guide.

A lot of people are frustrated that small tweaks are now as expensive or more than the kit they originally purchased.

We can't have it all...and tweaks give us a boost the OEM couldn't give because of design or cost...

This is no different to most hobbyists....Cars bikes ect...

It may help to get a picture of what helps and at what gain....

Would you let a friend spend $300 on a cheap amp dac then spend $2000 on accessories? When that $2000 should have been invested at the start.

That friend is people coming to CA for advice.... There isn't any doubt about benefits of power or modules to improve SQ either USB or Ethernet...

I have said this before on other sites there are 1000's of years of experience here. A sticky of cost benefit or something that guides.?? Basics to cost no object)??. The kindness and knowledge is here, it just is hard to glean from the threads.... What do people think...?

 

I am at 25% of my original purchase in add ons.

Cables to clockers. ... It's a hard choice as there is no hard facts just personal impressions.. but there is broad areas to cover before we argue over the fine details...

 

Poor man rant over..... I am not saying we have to ignore or pick just a few manufacturer's. .

Diminishing benefits, some are lucky to be in a position to know....

 

Keep smiling

 

Dave

 

Sent from my SM-G900F using Computer Audiophile mobile app

[r_w]

LPS have been key in optimising my system.

 

Swagman Labs SE edition LPS have been a revelation and at circa £200 each they are not such an expensive purchase, given the quality of components inside.

 

As stated above, LPS can offer huge positive impact on digital circuits.

 

I have seen people use very long digital chains in an attempt to find nirvana, but a simple chain: Intona feeding W4S Recovery via these brilliant LPSs had been the answer in my system.

 

The key improvements came from using high quality LPS on all digital circuits and achieving complete galvanic isolation (by powering the Intona via LPS using a split cable that does not connect the gnd = only the 2 data rails are connected from the Aurender).

 

In my system I can handshake with the gnd connected and then switch it out afterwards... the bass is utterly superior with gnd lifted.

 

I have stopped tweaking now optimisation appears to be 'done', as in, I can't see where I would find much improvement, I just listen without worrying what could be missing.

 

Ignore LPS on digital circuits at your peril.

 

;-)

[alfe]

No, we aren't overemphasizing the importance of power supplies in general.

However, with the computer it is possible to get markedly improved results by further cleaning up the internal SMPS supply to the peripheral devices such as the Optical device and internal SSDs, WITHOUT replacing the SMPS with an expensive Linear PSU.

 

Alex

 

Optimizing Solid State Drive Power Architecture | DC-DC Converters content from Power Electronics

[Cornan]

LPS have been key in optimising my system.

 

Swagman Labs SE edition LPS have been a revelation and at circa £200 each they are not such an expensive purchase, given the quality of components inside.

 

As stated above, LPS can offer huge positive impact on digital circuits.

 

I have seen people use very long digital chains in an attempt to find nirvana, but a simple chain: Intona feeding W4S Recovery via these brilliant LPSs had been the answer in my system.

 

The key improvements came from using high quality LPS on all digital circuits and achieving complete galvanic isolation (by powering the Intona via LPS using a split cable that does not connect the gnd = only the 2 data rails are connected from the Aurender).

 

In my system I can handshake with the gnd connected and then switch it out afterwards... the bass is utterly superior with gnd lifted.

 

I have stopped tweaking now optimisation appears to be 'done', as in, I can't see where I would find much improvement, I just listen without worrying what could be missing.

 

Ignore LPS on digital circuits at your peril.

 

;-)

 

Well done r_w! Just a few tips if you feel the need to potensially gain some SQ:

 

1. Try out the SBooster Vbus2 Isolator on the USB data plug. Improves even a 2-wire USB cable IMO.

 

2. Check out external grounding like for example Entreq Minimus/Tellus or Acoustic Revive RGC-24. Brings USB audio to life IMO!

 

Unfortunately there is no end game...but we can step-by-step improve things. I am personally tearing my hair to understand how to acheive a proper star ground for my entire setup, a dedicated power socket, only have one gear powered by the mains and remaining powered by battery (to prevent backwards noise into the mains) etc. Even if I pull everything off I am 100% sure it is not the end game...but I hope it will be a place where I can be content and start to enjoy the music without the analythic ears! ;-)

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[Astralark]

Well done r_w! Just a few tips if you feel the need to potensially gain some SQ:

 

1. Try out the SBooster Vbus2 Isolator on the USB data plug. Improves even a 2-wire USB cable IMO.

 

2. Check out external grounding like for example Entreq Minimus/Tellus or Acoustic Revive RGC-24. Brings USB audio to life IMO!

 

Unfortunately there is no end game...but we can step-by-step improve things. I am personally tearing my hair to understand how to acheive a proper star ground for my entire setup, a dedicated power socket, only have one gear powered by the mains and remaining powered by battery (to prevent backwards noise into the mains) etc. Even if I pull everything off I am 100% sure it is not the end game...but I hope it will be a place where I can be content and start to enjoy the music without the analythic ears! ;-)

 

Sent from my Nexus 7 using Computer Audiophile mobile app

 

I think you can change your DAC like DAVE or NADAC (Revena clock protocol) etc. Those ones are pretty immune to source errors.

 

 

Sent from my iPhone using Computer Audiophile

[Cornan]

I think you can change your DAC like DAVE or NADAC (Revena clock protocol) etc. Those ones are pretty immune to source errors.

 

 

Sent from my iPhone using Computer Audiophile

Thanks! As I said there is no end game. Chosing AOIP is an expensive path. However, it seems that PS Audio LANRover USB Transport have just been released http://www.psaudio.com/lanrover-usb-transporter/. Might do the trick to improve SQ for less money?

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[mmerrill99]

No, we aren't overemphasizing the importance of power supplies in general.

However, with the computer it is possible to get markedly improved results by further cleaning up the internal SMPS supply to the peripheral devices such as the Optical device and internal SSDs, WITHOUT replacing the SMPS with an expensive Linear PSU.

 

Alex

Yes, targeting the important areas with in a computer with PSes appropriate to the task is optimal rather than addressing the overall computer power supply. The individual power requirements are surprising when one looks at various areas within computers - the SSD paper that Alfe lined to shows 3.3V @1.5A, 2.5V@1A & 1.8V@1A. These are not power requirements in the various computer subsections such as memory, etc.

 

As is stated in this linked paper - "The SMPS must be a synchronous buck converter, versus a linear regulator or asynchronous buck converter, to provide high efficiency at such high load currents."

 

This is the problem - the high current draws & transient requirements are the limiting factors in PSes. Pses are used which are efficient while their voltage sag & power network noise is below the level required for reliable digital operation. So in the digital domain everything is fine but once an analogue device is connected to this system, the electrical noise level may become noticeable as we are seeing with the current focus on USB.

[sdolezalek]

A few really interesting points made:

 

I think what has been a surprise was the effect that clean supplies have on digital circuits. In my home built stereo, the power supplies seem to eat up about 80% of the real estate, and maybe close to that of the budget.

 

Having power suplies eat up 80% of the budget seems excessive, but not inconsistent with sandyk's comments.

 

So in the digital domain everything is fine but once an analogue device is connected to this system, the electrical noise level may become noticeable as we are seeing with the current focus on USB.

 

Yes, it seems the connection between mixed digital and analog components puts more pressure on clean power supplies.

 

LPS have been key in optimising my system. As stated above, LPS can offer huge positive impact on digital circuits. ... The key improvements came from using high quality LPS on all digital circuits and achieving complete galvanic isolation Ignore LPS on digital circuits at your peril. ;-)

 

That was my initial supposition, that you needed to add a high quality LPS to every digital circuit.

 

But Middy makes a good point as to where to draw the line and how much to spend on "improvements" versus buying better/more expensive gear in the first place:

 

On CA there is a drive to get the best out off the kit. As people rightly say.. power matters but at what cost....Maybe we need a chart of benefit V cost as a basic guide.

 

A lot of people are frustrated that small tweaks are now as expensive or more than the kit they originally purchased.

 

Would you let a friend spend $300 on a cheap amp dac then spend $2000 on accessories? When that $2000 should have been invested at the start?

 

I am at 25% of my original purchase in add ons. It's a hard choice as there is no hard facts just personal impressions.. but there is broad areas to cover before we argue over the fine details...Diminishing benefits, some are lucky to be in a position to know....

 

Of course part of it is that we are currently in the phase of disaggregating the value chain (separating software from hardware and separate boxes instead of complete solutions). The new EMM Labs DA2 that Chris is currently enjoying (at $25k per unit ) puts a number of those pieces back together into a single box with 16X upsampling and a dedicated USB solution. But, at $25K you can buy a lot of LPS's...

[Jud]

For people who have the time and inclination, power supplies are an area where DIY that isn't rocket science can pay real dividends.

[JJinPDX]

For people who have the time and inclination, power supplies are an area where DIY that isn't rocket science can pay real dividends.

 

Jud, can you point to more info on this.

 

JJ

[sandyk]

the SSD paper that Alfe lined to shows 3.3V @1.5A, 2.5V@1A & 1.8V@1A. These are not power requirements in the various computer subsections such as memory, etc.

However, an SSD itself will rarely need more than 750mA at +5V, and that's not a constant current draw either.

Many SSDs will need far less maximum current than 750mA.

Admittedly, the dual Regulated JLH PSU add-ons that I use to power my 2 internal SSDs are DIY, and also need available room to install them, but I can put one together for around $50 component cost alone.

[mmerrill99]

However, an SSD itself will rarely need more than 750mA at +5V, and that's not a constant current draw either.

Many SSDs will need far less maximum current than 750mA.

Admittedly, the dual Regulated JLH PSU add-ons that I use to power my 2 internal SSDs are DIY, and also need available room to install them, but I can put one together for around $50 component cost alone.

 

Is this averaged power requirements?

 

Just to illustrate this, here's the current requirements for DDR (from here) - a difference of almost 10 times between average & max power consumption (3.11Amp Vs 0.396Amps)

 

WORSE-CASE CURRENT CONSUMPTION —VTT Termination: Assuming the following structure for a 128-Mbyte memory system:

128-bit wide bus

8 data strobes

8 mask bits

8 V_CC bits

40 address lines (2 copies of 20 addresses)

192 lines

With each line consuming 16.2 mA, we have a maximum current consumption of:

192 × 16.2 mA = 3.11 A peak-V_DDQ Power Supply: V_DDQ sources current during the phase in which V_TT sinks current. It follows that the current for V_DDQ is unipolar, and its maximum equals the maximum value required of V_TT, 3.11 A.

Average Power Consumption: A 128-Mbyte memory system typically comprises 8- by 128-Mbit devices and consumes an average power of 990 mW, excluding the V_TTtermination power.⁴ It follows that the average current I_DDQ drawn from V_DDQ will be:

I_DDQ = P_DDQ/V_DDQ = 990 mW/2.5 V = 0.396 A

 

Irrespective of the exact values, the point is that the PS requirements of certain subsystems in computers require quite a sharp transient, high current delivery capability - a difficult ask of most PS systems

 

The general point about the importance of power supply in digital I agree with as a stable voltage reference is often a fundamental part of digital operation

[sandyk]

mmerrill99

 

I am only talking about SSD power in a PC here , as it is normally drawn from separate Molex sockets and can be readily supplied independently of the main Motherboard Power. The same applies to Optical devices too.

 

Alex

[agentsmith]

Is it a consensus that LPS is *better*? Is SMPS getting the bad rap of being the root of all evil unfairly?

 

As far as I know, respected high end brands like Linn, Jeff Rowland, dCS, Soulution has long been using SMPS on their high end components.

 

So should the problem with computer audio be attributed to cheap wall wart SMPS, rather than SMPS in general?

 

My feeling is bulky LPS is used for wall wart replacement is common due to their simplicity compared to a good SMPS. In fact, I have heard counter arguments that the ultimate performance level potential favors SMPS, is that not true?

 

If that is the right assumption, then SMPS should be the future for green reason.

[sandyk]

Most consumer grade SMPS have an obligatory high voltage, low value capacitor between Primary and secondary sides which sees quite a bit of RF/EMI being injected back into the A.C. mains supply, and then back into other components, as well as making the 0volts side of the supply have a mains related voltage at low current ,as high as half the actual A.C. mains supply voltage between it and mains earth. It is noisy as well.

When several SMPS sources are used with a system where the amplifier is connected to mains earth, you can get a rather nasty bite when unplugging interconnects. Their leakage is additive !

[r_w]

You are right, for sure Jeff Rowland have designed what they call a virtually noise free SMPS for their new preamps, but these are powering mainly analogue circuits. I think green tech was their key motivation.

 

I have no problem with the potential of SMPS as a near perfect supply - it's just that very few good ones exist right now.

 

Digital appears to be extremely sensitive to the generally available SMPS standard and there are lots of good LPS available that bring very noticeable SQ gain to counter this, but yes there shouldn't be a reason why someone can't create a brilliant SMPS for the same purpose of improving SQ.

 

Universal Voltage input are efficiency are obvious benefits of SMPS, but right now LPS typically outperform all but the best SMPS.

 

 

 

Is it a consensus that LPS is *better*? Is SMPS getting the bad rap of being the root of all evil unfairly?

 

As far as I know, respected high end brands like Linn, Jeff Rowland, dCS, Soulution has long been using SMPS on their high end components.

 

 

If that is the right assumption, then SMPS should be the future for green reason.

[Cornan]

Is it a consensus that LPS is *better*? Is SMPS getting the bad rap of being the root of all evil unfairly?

 

As far as I know, respected high end brands like Linn, Jeff Rowland, dCS, Soulution has long been using SMPS on their high end components.

 

So should the problem with computer audio be attributed to cheap wall wart SMPS, rather than SMPS in general?

 

My feeling is bulky LPS is used for wall wart replacement is common due to their simplicity compared to a good SMPS. In fact, I have heard counter arguments that the ultimate performance level potential favors SMPS, is that not true?

 

If that is the right assumption, then SMPS should be the future for green reason.

 

Interesting thoughts agentsmith! In fact I have heard the very same thing. A good constructed SMPS can possibly concur a good LPS. Even John Swenson said on the LPS-1 thread that some SMPS could potensially release less noises back into the wall than some LPS due to how well it is constructed in that point of view. With SPMS most people are usually referring to a simple wallwart...but there are proper SMPS that I would'nt hesitate one moment to use in my own system.

 

There is also the point how well you take care if the AC power (and grounding). If all PSU's are plugged into a power conditioner with individually filtered power sockets I personally do not think that the backward noise is a big concern. You could also through in some Isoplugs besides your computer and other noisy mashines "for braces" if you want to be extra safe from external noises. If you do not like power filters you will have to try other paths like well constructed BPS (not connected to mains while playing music), Isolation transformers etc etc. In the end we all have to rely on trial and error. There is short comings on anything we choose...and we cannot try everything. Just head towards our own believes & knowledge and others impressions & knowledge and hope for the best!

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[agentsmith]

 

There is also the point how well you take care if the AC power (and grounding). If all PSU's are plugged into a power conditioner with individually filtered power sockets I personally do not think that the backward noise is a big concern. You could also through in some Isoplugs besides your computer and other noisy mashines "for braces" if you want to be extra safe from external noises. If you do not like power filters you will have to try other paths like well constructed BPS (not connected to mains while playing music), Isolation transformers etc etc. In the end we all have to rely on trial and error. There is short comings on anything we choose...and we cannot try everything. Just head towards our own believes & knowledge and others impressions & knowledge and hope for the best!

 

My *limited* understanding is the high end SMPS from Linn and the like design their switching frequency to be very high such that the "backward noise" will not affect other audio equipment.

 

The way I deal with my setup is to have dedicated circuits for my audio equipment like the CD player and my Devialet amplifiers. Another dedicated circuit for "dirty" equipment like the a Mac Mini (USB Out) TV, set top boxes and network equipment, all those equipment are plugged into a PC Audio Ultimate Outlet. For audio player I have another dedicated circuit for a Squeezebox Touch (USB out, powered by Teddy PS).

[Cornan]

My *limited* understanding is the high end SMPS from Linn and the like design their switching frequency to be very high such that the "backward noise" will not affect other audio equipment.

 

The way I deal with my setup is to have dedicated circuits for my audio equipment like the CD player and my Devialet amplifiers. Another dedicated circuit for "dirty" equipment like the a Mac Mini (USB Out) TV, set top boxes and network equipment, all those equipment are plugged into a PC Audio Ultimate Outlet. For audio player I have another dedicated circuit for a Squeezebox Touch (USB out, powered by Teddy PS).

 

Awesome! That is where I am heading right now as well...ie. on the way but not there just yet. I am planning dedicated circuits for my audio equipment plus a completely star grounded setup. I strongly beleive this plus external grounding of each equipment is the way to go. I just have'nt fully understood how to perform the star ground in my perticular case yet though.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

[paulhynes]

Hello Cornan,

 

Unfortunately star grounding your complete system to one ground point may generate electrical problems, as it is likely to cause ground interaction problems if each item of equipment already has a ground connection via equipment interconnects. Inter equipment communication usually requires a signal and a ground return to transfer information signals from one item of equipment to the next. If you then additionally connect each item of equipment to a star ground you will be creating multiple paths for the ground return currents of the items of equipment. Galvanic isolation of signal and ground lines between items of equipment will prevent the multiple ground loop paths from forming.

 

During the mid 1990s I wrote a series of small articles about power supplies and star grounding which were published in an underground UK magazine called Common Ground. I have retained the copyright so can reproduce the articles at will. I have edited the original articles slightly to tidy up the text. The basic principals are still the same and still apply to modern equipment. I do not profess to be a good technical writer and the articles are rather simplistic by modern standards and do not cover every aspect of these topics, but this may help you understand more about power supplies and grounding requirements in audio systems.

 

If Chris has no objection I will post a copy of the articles in this thread.

 

Regards

Paul

[Cornan]

Hello Cornan,

 

Unfortunately star grounding your complete system to one ground point may generate electrical problems, as it is likely to cause ground interaction problems if each item of equipment already has a ground connection via equipment interconnects. Inter equipment communication usually requires a signal and a ground return to transfer information signals from one item of equipment to the next. If you then additionally connect each item of equipment to a star ground you will be creating multiple paths for the ground return currents of the items of equipment. Galvanic isolation of signal and ground lines between items of equipment will prevent the multiple ground loop paths from forming.

 

During the mid 1990s I wrote a series of small articles about power supplies and star grounding which were published in an underground UK magazine called Common Ground. I have retained the copyright so can reproduce the articles at will. I have edited the original articles slightly to tidy up the text. The basic principals are still the same and still apply to modern equipment. I do not profess to be a good technical writer and the articles are rather simplistic by modern standards and do not cover every aspect of these topics, but this may help you understand more about power supplies and grounding requirements in audio systems.

 

If Chris has no objection I will post a copy of the articles in this thread.

 

Regards

Paul

 

Thanks a lot Paul! I would be very interested to read your articles about star grounding. It is fairly difficult to find useful audio related articles or information in the subject.

So far I am aiming to power all devices except one, ie. my DAC/Pre/HPA, by battery power (disconnected from mains while playing music). I will only use 2-wire unshielded USB cable (data only) and XLR cables to my headphones. This means that in reality only one gear will be star grounded..my Pioneer U-05. My problem is to understand how the external grounding will affect the star grounding and ofcourse if my theory will hold true IRL? [emoji51]

 

Anyway, if you cannot post your article here I would appreciate if you could pm the link to me!

 

Kind regards,

Micael

[Middy]

+1 Every day is a school day....

 

Sent from my SM-G900F using Computer Audiophile mobile app