LPSU choices, new contender.....

[marce]

Needs to put this symbol on the PCB's as well as text to cover himself... The lightning symbol, international symbol for high voltage.

https://www.pdsigns.ie/product/safety-electrical-hazard-mains-voltage-warning-sign/

High voltage, hi current parts for these sort of simple PSU's are easier in PTH for the market and volume he's going for, also allows modification.

[marce]

14 hours ago, Neverfinished0 said:

That's it guys - Have fun arguing incessantly amongst yourselves - I do not have time to waste with this nonsense.
I joined the group yesterday to protect one of my very satisfied customers who had the temerity to suggest alternatives to cheap Chinese LPSUs and very expensive ones.
I told him not to take any notice of Forums as they are full of people the majority of whom do not know much about the subject.
I will now leave - having fielded over 150 inane comment emails today - yet successfully helping my client out a bit with my support and expertise and showing my "ignore Forum comments" as being true .
Thanks for the Fish and Goodbye!
 

Instead of spitting your dummy out of the pram, why not answer some of the points, it would gain more respect for your products...

 

[marce]

13 hours ago, jabbr said:

More important to look at ESR/ESL particularly if we are talking about bypass caps and high speed digital — so the application is important — basically SMD beats through hole in “lead” inductance, also it’s harder and harder to find old style jfets but the little critters are cheap and a roll will last a lifetime.

 

Some of the new packages have much lower inductance.

Not just high speed digital, there is a lot of high speed analogue and microwave is creeping down onto (almost) standard PCB's (still specialist construction with one or both outer layers for the CPWG style routing. Power delivery is critical in all electronics and what goes on at a board level is far more important to the circuit operation than whether the main PSU is linear or switched. Most digital based designs will have several local PSU's, higher current will be SMPS, lower current and sensitive will be local low noise LDO's, some circuitry will have a filtered local supply from the main supply. Critical crystals (I am talking microwave, phase array) will have the PSU on the opposite side of the board as close as you can get it, effectively the power going up through the board stack, minimal inductance.

There are endless books and information on power delivery systems. We do on average at least on course or seminar every two years on the stuff, just to try and keep up...

When digital circuits switch, the instantaneous power does not come from the main PSU it comes from the local capacitance to the device, on die capacitance, any lead capacitance, PCB power plane capacitance, local decoupling capacitor capacitance, reservoir capacitors, power supply. All those are listed in order of importance and also the order of inductance, lowest first...

[marce]

22 hours ago, 4est said:

Although I do not disagree with these statement, I do not see how this is apropos through the meter long cable from this external power supply to the load. This seems especially true considering that not only are we fighting the lead network IRL, but that there is likely some sort of regulation between this power supply and the load as per your example. Perhaps I am daft, but it would seem to me that an external power supply cannot react at these frequencies. I am sure you know way more than I, and I'd like to understand. Perhaps you are speaking in generalization?

The final power supply is to slow to react to the instantaneous current requirements of digital switching, hence the local capacitance and reservoir caps as I mention.

[marce]

17 minutes ago, jaaptina said:

Not having the knowledge but thinking from this point. Is there a point in having a power supply, (long) cable, MPAudio SD-HPULN LT3045 dc-dc converter, very short cable, dac/streamer configuration? 

 

Shorter the better, inductance slows current delivery down, on PCB's for longish supply runs (not power planes) such as 24V to an section of circuitry the supplies are run as broadside coupled traces on multiple layers, so you have power, return, power, return, it gives a low inductance relatively high capacitance feed similar to bus bar routing for high power.

[marce]

11 hours ago, Superdad said:

 

I'm a fan of split bobbin trans too, but good luck finding then in anything larger than 48VA.  And they often are mechanically noisy (lam buzz) when you pull real current through then.  Unlike R-cores, which have near the performance, lower flux field radiation, are available in larger sizes--and are DEAD SILENT!

Worked on  a 16kW 230V SMPS, that had input and output differential and common mode chokes and a litz's wound transformer, the magnetic's guy was up there in the world of RF engineers... half mad scientist/half hippy.

 

[marce]

2 minutes ago, jabbr said:

 

It depends on what is being supplied, but if tighter regulation is helpful then yes. This is called a “pre regulator” and the design pattern might be to step down a supply and allow LDO which reduces the heat generated in the final board. In other cases on board LT3045s might be cascaded to generate the full complement of needed voltages. On board is best.

The general rule is main supply, which often depends on the final location for the design, then main onboard supplies, usually SMPS to keep heat generation down to provide the required main voltages, usually 3V3, 5V, +/-6-12V for analogue, then local LDO's for the device local supplies such as 2.5V, 1.8V, some FPGA's having up to 5 separate supplies, core, I/O, PLL's etc.

[marce]

16 hours ago, Ralf11 said:

batteries, people

 

batteries

Battery output impedance tends to go up with frequency so regulator and caps needed...,

 

Again the most important part of a digital supply is the decoupling caps near the devices, a battery is just another form of front end supply with its own noise and issues.

[marce]

34 minutes ago, Tomslin said:

Regarding batteries: Some Ultracaps as near the device as possible will be fine, feeding by batteries and no regulator.

 

Post from yesterday:

 

 

http://jplay.eu/forum/index.php?/topic/2350-jcat-net-card-femto/?p=48326

I wouldn't do this, I would always use a regulator...

[marce]

15 hours ago, Tomslin said:

I do it simply because I experience improvements. May I ask if you have another experiences to this? 😊

Digital requires a stable supply, the more stable the better, battery voltage drops with time and may fluctuate with current draw, and EVERY design I have worked on that used batteries had regulators or an SMPS after the battery, from recommendations and instructions from people who understand this far better than me...

[marce]

16 hours ago, Ralf11 said:

marce, what noise comes from a battery?

They have a resistance so there is thermal noise, electrochemical noise etc. Nothing is perfect in this world apart from an Audiophiles hearing...😀

Of course when your laying out a design using ADA4530, a few 16 bit DACs and a couple of 24 bit DACs you have to be concerned with very low levels of noise, small fluctuations in the power supplies at device pins.

I would always use a regulator and filter circuit after ANY raw power input...

[marce]

8 minutes ago, sandyk said:

 

Why did you feel the need to spoil an otherwise excellent reply with such a smart arse  shot at the vast majority of Audiophile Style  members ?

Just testing the general sense of humour on this site, 

Still nil😁

[marce]

3 hours ago, sandyk said:

 

Why did you feel the need to spoil an otherwise excellent reply with such a smart arse  shot at the vast majority of Audiophile Style  members ?

Lighten up, the reason why I can't be bothered to hang round here so much is to many people taking it far to seriously, almost religious in their damnation of anyone who goes against the tenets of audiophiledom.

Also the way that any question or physics brought up in one of the belief threads gets the poster shot down with accusations of being a troll etc.

I am beginning to think that to many audiophiles are becoming grumpy old men...

[marce]

26 minutes ago, Tomslin said:

 

Thank you for your clarification 😃

 

Although I don't quite agree with these "old truths". They allow certain grade of modification, imo.

 

A hint for you can be; don't trust people who claim they know and understand better than you do 😉

 

Another link at the subject:

http://www.tirnahifi.org/forum/viewtopic.php?f=8&t=4652

 

I work on very high level of designs every day and have done for 35 years, I am talking stuff that goes in space, steerable phase array microwave antennas, mill stuff such as communications, missile launchers, medical stuff, working on some cool stuff now, 4 x 24 bit DACS, 8X16 bit DACS some fed by ADA4530 so I have metal cans over the analogue circuitry dual floating supplies on the rear of the board and guard tracks all round the analogue signals... So the information I have comes from instrumentation level design and layout, we know it works because it has to...

 

[marce]

Just now, RickyV said:

 

Mmmmm, I was thinking more or less the same thing about the objectivists around here.

Probably true as well... Hence I go practice my Bass guitar now when I get the urge to post, very therapeutic, slam out some grooves. 😀

 

[marce]

18 minutes ago, Jud said:

 

Since he designs circuit boards for mission critical digital equipment for a living, perhaps he has developed some sense of who to trust with regard to particular aspects of battery power supply design.

Cheers Jud. Not just battery supplies, I started a list of all power supplies I have worked on, lots over the years, from 35kV supplies down to low current on board LDO's, SMPS's, LPS's, supplies with batteries and integral chargers... supplies with big batteries, little batteries, invertors, lots of interesting stuff, always remember the first mainframe supplies, emitter coupled 2n3055 by their hundreds in a 1U tray to get the current, the good old days. LOL

[marce]

10 hours ago, sandyk said:

 

A high quality battery supply (LiPo etc.) is normally better at preserving a neutral sounding presentation,
 but the main problem is that the voltage reduces slowly with use, and then may vary considerably under different load conditions, even generating audible noise.
Most devices however, require a stable input voltage for the highest consistent performance.
 The only way around this is to use voltage regulation. Unfortunately, the type of voltage regulator used ,
 and the necessary capacitors used with it for stability reasons mainly, usually imparts some kind of audible footprint.

 This is more important with the Analogue area than the Digital areas that Marce mainly  plays around in where you can  use well established HF bypass techniques etc.

If you read my posts I don't do just digital, I do a mixture, analogue/digital, microwave. As siad doing a card now with multiple ADC/DAC with lots of analogue circuitry. I do more mixed designs than I do purely digital designs. I do a lot of instrumentation level analogue layout...

[marce]

I do worry about capacitors not directly in the signal path having an effect on the analogue output, if I did a board where that happened it would be considered a failure...

[marce]

1 hour ago, sandyk said:

 But what are you using in  your own Audio system, not instrumentation etc.?

It is a generalisation, how do capacitors in the PSU have an effect on the resultant analogue output, and if they do it will be measurable...

[marce]

There will be voltage regulators on the cards, you wont be bypassing those I presume!

Depending on the digital circuit the instantaneous current requirements when the circuitry switches can be up to 100A, even small circuitry have high current demand when switching, that,s why the whole power delivery system is critical. Even more so on digital/analogue designs. The most important components in the power delivery system are those very small (0402 preferable) decoupling capacitors right next to the power pins and how they are tracked to the pins and power planes.

Whatever front end power you use must be within the requirements of the circuit its feeding and avoid voltage droop at all costs.

[marce]

9 hours ago, sandyk said:

 I was asking what actual equipment you are using in your own Audio system.

Still using something like a SBT ,without even a decent Linear PSU such as designed by John Swenson and used by numerous DIY Audio members ?

 

Fender Jazz bass, Fender 200W rumble amp.

[marce]

9 hours ago, sandyk said:

 I was asking what actual equipment you are using in your own Audio system.

Still using something like a SBT ,without even a decent Linear PSU such as designed by John Swenson and used by numerous DIY Audio members ?

 

More worrying is your way of trying to put someone down so as to discredit what they say... SAD.

[marce]

5 hours ago, sandyk said:

 Jud

 Marc keeps telling us how qualified he is in the area he works in, and I don't dispute his expertise in that area,

however it does not mean that this knowledge automatically transfers added benefits to normal consumer Audio products that were also designed by competent E.E.s to a level often limited by cost factors .

 Marrying the Digital area to the Analogue Audio area is more of a " black art" where very few designers excel, and many use textbook implementations from the Semiconductor Applications Engineers. 

 You only need to look at Rajiv's thread to realise that your typical products from competent E.E. designers are often capable of further marked improvements. 

 

Alex

F Off its getting monotonous, I have to defend my self to counter your endless putdowns, you are the grumpy old man I have mentioned previously. I have posted no put downs just some relevant info, I stopped posting because of endless putdowns, off topic comments aimed at a person, back to my bass, I can't be bothered. Goodbye.

[marce]

4 hours ago, Jud said:

We all might wish for a little more cross-fertilization.  Would be interesting to see what marce thought of Pavel's implementation of Miska's DSC-1, for example, since that's hardware without proprietary IP in the way.

Pavel from DIYA?

Got a link...

[marce]

10 hours ago, Jud said:

We all might wish for a little more cross-fertilization.  Would be interesting to see what marce thought of Pavel's implementation of Miska's DSC-1, for example, since that's hardware without proprietary IP in the way.

Found it, its the Ladder DAC. Will have a look, my initial comment would be that I would use resistor packs with matched resistors, easier assembly, thermally connected resistors etc.