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FS: „Ultra Low Noise“ Power Supply, LT3045 based PCB’s

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#248
Hi there,

there was a mistake in my webshop MPAudio | Highend for Audio applications regarding pricing, which is now corrected!

All prices are valid for all orders, not depending on the country you order from. In case taxes have to be paid, it is included, covered by MPAudio and will correctly be shown within the invoice!

Many thanks to people pointing that out! It took a few days to adapt the webshop...
Affected people got back the too much paid money back, of course 😉

Best regards

Stammheim
 
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#251
Hi Cornan,

I'm just a recent visitor to these pages and was wondering if you could direct me to information about the "often mentioned" balanced power or could add a circuit of both this and your power supply arrangements - it seems as tho you're are using multiple regulators in series with different current ratings, etc - rather puzzling about how the floating ground points are all connected
 
#252
jameshillj said:
Hi Cornan,

I'm just a recent visitor to these pages and was wondering if you could direct me to information about the "often mentioned" balanced power or could add a circuit of both this and your power supply arrangements - it seems as tho you're are using multiple regulators in series with different current ratings, etc - rather puzzling about how the floating ground points are all connected
Click to expand...

Few words but many questions. Difficult to direct you to any info since I have’nt saved nor built the balanced ac-ac ps myself. I have bought it ready made. The thing with balanced transformers is that they cancel all the noise by design. The thing with floating ground is that the transformer will get isolated from the AC mains. That is done by connecting the safety ground IEC input directly to the chassi. Not passing it through to the output.

The dual LT3045 in parallel have a reason. The more parallel LT3045 the better ripple rejection and series seems to boost that performance. IME it does’nt matter if you have a 1A in front of a 5A. It improves in series as well as long as the powered device does’nt require more than 1A.
I would love to try a 10A or even 20A LT3045 in series for a 1A current device just because the total amount of current in parallel AND series matters big time.

Balanced. I do not know how much you already know about it? It requires two toroidal transformers. Two 230-2x 6VAC transformers or one 230-230VAC to 230-2x 6VAC transformer. It will in theory cancel out all of the transformer artifacts.

In my case the AC mains Wall outlets is 2-Pole followed by a DC blocker trap filter into a balanced isolation transformer with a star-earthed grounding point into a star-earthed and starquad wired power distibutor.
 
#253
Thanks Cornan for your clear reply

Aah, the mains balanced system using a centre tap connection of the secondary winding of a 230:230 isolation transformer to connect to a separate ground, to give a '+/- 115' volt (ac) as the new mains input power - got it, thanks. (I assume I did get it right?!)

I wonder if this new balanced power mains would need a separate dc blocking trap for each of the ac input lines if the isolation transformer is feeding a number of other linear power supply transformers?

I assume this 'new central ground' is the focus of the systems other components ground (star-earth ground system) connections - I wondered about this.

It's quite intriguing to see that computer audio/digital components respond to multiple series regulators to produce an increase in the 'downward dynamics' that Allan Wright wrote about (or just better sound)
 
#254
I do sometimes wonder what people must have coming through the wall as a mains supply. If there's little/no measured DC offset on your mains supply then a balanced mains transformer is moot. Far better to add a couple of common mode chokes after the secondaries and a DC blocker beforehand if particularly plagued by asymmetry on the incoming mains.
 
#255
sq225917 said:
I do sometimes wonder what people must have coming through the wall as a mains supply. If there's little/no measured DC offset on your mains supply then a balanced mains transformer is moot. Far better to add a couple of common mode chokes after the secondaries and a DC blocker beforehand if particularly plagued by asymmetry on the incoming mains.
Click to expand...

Question. Have you tried both options? Balanced rules my world, but I would not mind if someone that have tried both ways convinced me to choose the common mode choke path. I am rather convinced that no filters and no chokes is what I want so I’ll need to be convinced quite hard I’ll guess! 😀
 
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#258
sq225917 said:
I found a large balanced mains transformer 3000VA provided no benefit on on powers, dac, phono or pre, or even on all of them.

Common mode chokes on my phono psu, pre rectifiers were clearly audible as beneficial
Click to expand...

I have found that large transformers are not the way to go. Smaller transformers in a balanced configuration is way better than big ones in unbalanced mode. It will relief the transformer from heavier duties and cause less transformer artifacts.
 
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