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anewmission

Linear power supplies

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1 hour ago, frednork said:

The problem is smps's injecting noise into the circuit.

 

Absolutely!  :thumb:

 

1 hour ago, frednork said:

Would either filters or iso trans do the same job (or better)

 

I use both in my 'Isotran' units.  As you're in Vic, maybe I can lend you one to try out, if you'd like.

 

 

Andy

 

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Thanks Andy, might take you up on that. The theory only takes you so far, nothing like trying it out to see if a difference is heard.

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54 minutes ago, andyr said:

These transformers do not (well they should not!) isolate from ground.  If they do ... the RCD in your power distribution box becomes useless.

 

What they do do is ... isolate the secondary active/neutral lines from the primary active/neutral lines.  Which, for one, stops DC from passing ... but, I suggest, still allows mains hash to pass through the transformer (given that magnetic linkage passes AC).

 

You should look up MEN - multiply earthed neutral - the system we use for power.    Before RCDs, isolating transformers were a safety device. The normally earthed neutral is isolated, from ground, because it is now a floating output of the transformer.   https://www.powerinspired.com/isolation-transformer-need-know/

Edited by aussievintage

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On 13/10/2019 at 9:28 AM, anewmission said:

Is there any point in buying the budget ones from eBay or aliexpress?

I don't believe so.  Not unless you can evaluate just what your are getting in terms of design and quality.  There is no magic in just swapping cheap linear for cheap switching.

 

 

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1 hour ago, anewmission said:

So back to my original post...

I did buy this one for my Topping D50.

I bought this one specifically because there was a write up on this circuit as a good recommended one. Not sure I can find it again though.

https://www.ebay.com.au/itm/DC-25W-DC5V-3-5A-TALEMA-25VA-ring-Ultra-Low-Noise-Linear-Regulated-Power-Supply/273006837224?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

 

This one is the TALEMA 25VA transformer.

Edited by rocky500

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7 hours ago, aussievintage said:

You should look up MEN - multiply earthed neutral - the system we use for power.    Before RCDs, isolating transformers were a safety device. The normally earthed neutral is isolated, from ground, because it is now a floating output of the transformer.   https://www.powerinspired.com/isolation-transformer-need-know/

 

Correct, av.  But the input earth to the isotran continues to its output sockets - so earth is not floating/isolated.

 

8 hours ago, frednork said:

The theory only takes you so far, nothing like trying it out to see if a difference is heard.

 

Absolutely!  :thumb:

 

7 hours ago, anewmission said:

So back to my original post...

 

:sorry:

 

 

Andy

 

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On 13/10/2019 at 10:28 AM, anewmission said:

 

I am considering buying a linear power supply to upgrade my Dac. (topping D50)

Just wondering what people's thoughts on this are.

Is there any point in buying the budget ones from eBay or aliexpress? Considering the Dac was only 300 I don't want to go overboard.

I also noticed that bryston use linear power supplies to their turntables.

 

My turntable is 15v input, I'm wondering if there is dual linear psu (5v and 15v outputs in the same chassis)

 

Any help is appreciated

 

 

You've had lots of responses - so you should've been able to pick up that there are several ways you certainly will get improved sound by upgrading power to your D50.  But cheap solutions - either linear or switched mode - probably won't give as big an improvement as more costly ones.  And I suggest it is irrelevant what your DAC cost - if you'd bought a $1000 DAC, you'd probably be facing the same issue.  :lol:

 

Andy

 

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9 hours ago, andyr said:

ut, I suggest, still allows mains hash to pass through the transformer (

no, incorrect, the transformer blocks high frequency.  Read all about it here https://www.schneider-electric.com/resources/sites/SCHNEIDER_ELECTRIC/content/live/FAQS/123000/FA123947/en_US/Isolation.pdf

 

Still amazes me how you can give people a solution to an issue, then be ignored 

 

Carry on children

:)

 

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15 hours ago, frednork said:

I run a digital front end with networking etc. I have a 2000w isolation transformer and as I run an integrated with a dac I prefer the sound of it plugged into the Isolation transformer. I have 2 pc's (server and rendere) with good quality linear psu's, A switch with a cheap linear psu. Then there is a htpc android box with an smps, A wireless extender (w smps ) and a tv (assume with smps) Considering the noise injected back into the line from cheap SMPS's. Where should everything be plugged in (and should I get another isolation transformer?

Plug in everything to the isolation Transformer that doesn't have a Linear Power Supply, which would probably exclude your integrated and include almost everything else

As the transformer acts as a big inductor they tend to filter HF waveform distortion or as commonly known in Aufiophilia Land, hash on the mains  

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3 minutes ago, Dirkgerman said:

no, incorrect, the transformer blocks high frequency.  Read all about it here https://www.schneider-electric.com/resources/sites/SCHNEIDER_ELECTRIC/content/live/FAQS/123000/FA123947/en_US/Isolation.pdf

 

Still amazes me how you can give people a solution to an issue, then be ignored 

 

Carry on children

:)

 

 

I get a different conclusion, reading the article you linked to, Dad.  You are correct ... only if the transformer has an electrostatic shield.

 

Andy

 

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Caution:

 

A chunky big piece of metallic object of which linear power supplies mostly comprise of will severely damage the audio system's soundstaging capability - simply just by sitting there in close proximity. It's physics, no 2 ways about it. So by trying to avoid one issue, another problem is created.

 

So ask for a longer umbilical cord feeding the dac or whatever devices you're trying to enhance. Place that LPS as far away as that umbilical cord will allow.

 

Minimum safe distances to avoid magnetic field interference have been observed to require up to 3 meters...

Edited by jeromelang

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2 minutes ago, jeromelang said:

A chunky big piece of metallic object of which linear power supplies mostly comprise of will severely damage the audio system's soundstaging capability - simply just by sitting there in close proximity. It's physics, no ways about it.

What physics is this?

4 minutes ago, jeromelang said:

Minimum safe distances to avoid magnetic field interference have been observed to require up to 3 meters...

Do you know the magnitude of the forces you're describing?

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Yep and Toroidy do them in a Supreme with all the shielding. You don't use these ?
 
These are sold to my Clients as well as DC Blockers to bring their Systems to Life  
 
https://sklep.toroidy.pl/en_US/c/Toroidal-transformers-AUDIO-GRADE/75
Dc blockers interest me.. Let's say I went from mains through the dc blocker into my art (rfi emi filter) power conditioner and had everything hooked up to the art, I would be getting a better result?

Having lps coming from the art into different devices that's the best set up apart from an expensive power regen?

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