[rb2013]

   
Hi Pakultra and thanks for the very interesting advice.
Clearly i am not really serious in my approach for different reasons.  Just to start i have no scope to see what is going on in a circuit.
I am just peeping inside famous units of great sound hoping to learn something.   A schematic would be much helpful for this.
The parts you have selected i guess are the best available.  As you say it is difficult to foresee if they will have any impact on sound.
Maybe it is trivial but for a me a great unit starts with a great power supply.
And in low signal units suppression of all kind of noise (mains noise, diodes noise, EMI/RFI noise) is fundamental.
But again your approach to kill the noise after the transformer is equally good.
A scope more than a ear could show the situation.   A scope is much more sensitive than a human ear.
Where will you buy these parts from ?  i like the Shaffner filters very much.  I could skip on the transformer replacement and try one of these filters.
Maybe the outcome would be even better ?
Just as a reference this is a very good dac from Schiit Audio ... actually their new TOTL dac said to have an exceptional sound.
 
http://schiit.com/public/upload/general/imagecache_thumbnail_product_gallery_large/yggdrasil_pcb_1000.jpg
 
Looking at its power supply can give important hints about how a PS for digital euipment must be designed.
A very strong chain clerly cannot have weak links. If all the dac is extremely good the PS must also be very good indeed.
Anyway also dealing with the PS noise at regulators level could work perfectly the same (actually even better ... maybe i am overrating this PS issue).
So my idea is that the same parts (with the right ratings of course) put in a cheaper unit could give some benefits.
For the best units that provide the best sound possible the parts selected can be the best available. Cost is less of a constraint and top sound is the goal.
You see ? no toroidals ... attention to mains filtering and rectifying diodes ... chokes ...
Do you have some pics of your modified U12 ?  how are you placing the new PS ?
I would think to a new box for sure.   Something bigger with the space for everything inside. The U12 box is already quite full of parts.
Thanks again,  gino

Or you could just run one of these right before the U12 or MXU8 - I have and the results are excellent and reversible. And relativly cheap.  The Pro version with the Advanced Power Filtering should not be confused with the non-Pro version which will do line by line EMI/RFI filtering.
 
The Advanced Power Filtering uses both Common Mode and Differential Mode filters, in addition to the EMI/RFI filters. 
 
From Blue Circle on Common Mode Rejection on their excellent and expensive $2,200 BC60X1:

The balanced power outlets offer another advantage. First of all, not only do they share all the filtering of the other outlets, there is also​

some additional filtering on the secondary of the transformer. Another advantage to using balanced power is a phenomenon called​

common-mode rejection or CMR. This can best be explained visually so refer to the figure below.​

When the center-tap on the secondary is tied to ground as in the figure above, any noise on one side of the grounded center tap is​

180˚ out of phase with the noise on the other side. This means that the noise on either side of the center tap will cancel out. This​

adds another level of filtering to these outlets. It also prevents any noise being generated by one component (such as clock noise​

from a DAC) from leaking into the power supply of another component connected to the conditioner. This offers a great advantage to​

components that are processing very low-level signals, like phonostages​

​

 
ART PB4x4Pro Power Distribution System with Advanced Power Filtering:
All PRO SERIES models have an additional internal discrete module called APF (Advanced Power Filtering) which filters out digital and dimmer hash as well as any high frequency noise that is above the audio range. Some off-the-shelf add-on modules saturate and lose their filtering effectiveness as the load increases, but by using a high power discrete design we were able to create a filter that stays effective over the full operating range.

By using both Common Mode and Differential Mode topologies in series for the filter design we are able to block virtually all of the unwanted noise that is between the AC line and ground, and also the two sides of the AC line. This has the additional benefit of reducing ground loop problems in your system. High frequency noise currents in particular are highly attenuated in both directions so that any line noise that could be generated by one of your components is not allowed to get back into your main A.C. wiring so if you use a number of PRO SERIES Power Conditioners in your setup, you can distribute and isolate the noisy components from the sensitive components in your system. Additionally, any signals above 10kHz are filtered from the line with over 40dB of attenuation above 100kHz and beyond.

Every PRO SERIES power conditioner is designed with a power capacity of 1800 Watts, surge/spike protection, APF with EMI & RFI filtering, front-mounted unswitched power outlet and an adjustable rear-mounted gooseneck light source for bright illumination behind the rack. The spacing and alignment of the rear outlets to accommodate various size power plugs and AC adapters.

Features:




 
Not bad for $85

1. APF - Advanced Power Filtering
2. Power Capacity of 1800 Watts
3. Surge & Spike Protection
4. EMI & RFI Filtering
5. 8 Rear Outlets with Power Adapter Friendly Positioning
6. One Front-mounted Unswitched Power Outlet

Non-pro version of the PB 4X4 with EMI/RFI at the AC and between each AC block ($49) - which the Pro version has in addition to the APS:

 

[abartels]

Hi ginetto61,

I like your idea of adding a mains filter like the type you showed us. I've done some searching and I am planning to order these based on their superior filtering specs:

Manufacturer	Schaffner EMC Inc
Manufacturer Part Number	FN2090-4-06
Description	FILTER MULTI-STAGE HI PERFORM 4A

Manufacturer	Schaffner EMC Inc
Manufacturer Part Number	FN2090-12-06
Description	FILTER MULTI-STAGE HI PERF 12A

These filters have two stages and look quite promising based on their datasheets.

Besides, I will test these in my power supply to see if they can actually improve things. These will cover almost all frequencies up to 5.5 GHZ

2			490-5055-ND	FILTER EMI 15A 25V 100KHZ-1GHZ		1 Immediate	0	5.52000	$5.52
3			445-2991-1-ND	FILTER 3-TERM .65 TO 2.5GHZ SMD		3 Immediate	0	0.82000	$2.46
4			445-2989-1-ND	FILTER 3-TERM 2.0 TO 5.5GHZ SMD		3 Immediate	0	0.73000	$2.19

I also believe that diodes are important. I've got 8 Cree diodes at hand that I ordered last week. These diodes are believed to be far superior to even the best Schottky diodes because they have zero recovery voltage or current spikes.

Manufacturer	Cree Inc
Manufacturer Part Number	C3D02060E
Description	DIODE SCHOTTKY 600V 2A TO252-2

I will most probably not be able to notice any improvement even if I do put these diodes into my ultra-quite power supply. I don't know. but it's fun to explore and learn...

Cheers

pakultra

Hi pakultra,

Be aware when implementing filtering, when using a 12Amp filter, and you only draw 1Amp, or less, filtering wont be adequate.

Search for version that suits the draw of your device.


Regards,

Alex

 

[prot]

rb2013 that's a cool filter, especially for the price.

Anyone who knows a comparable EU device ?

I was looking at https://www.youtube.com/watch?v=9mE-N1Ll6o8 but I find the €600 price exaggerated.

 

[pakultra]

@rb2013 that's a cool filter, especially for the price.

Anyone who knows a comparable EU device ?

I was looking at https://www.youtube.com/watch?v=9mE-N1Ll6o8 but I find the €500 price exaggerated.

@prot
 
I have a new pm for you. Please check. Thanks!

 

[pakultra]

@rb2013 Thank you for sharing that nice unit. It's so tempting. I almost bought it today after reading your post. But on second thought, I'd prefer isolated, individually filtered sockets to minimize possible interference between pc, dac, amp, etc. The Shaffner filters I was considering are also balanced filters. They have even higher attenuation (above 70dB). I am planning to get a metal case like that and put in 5 filters to cover all my audio related devices. 

 

[pakultra]

Hi Alex, thanks for pointing out that 12A is too much for small DACs. I was planning to add that 12A one before my Blue Circle mains filter since all my audio devices are connected to that filter. Now after seeing rb2013's post, I've changed my mind. I will use a few smaller filters to filter each device individually

 

[riffer]

Me, I ordered one the yesterday. I really just wanted to be able to use the I2S input on my Audio-gd Master 7 for music so I could free up the USB input for my HDPC. Ordered the HDMI mod for the Master 7. Looks straightforward, except adjusting for the different pin definitions.

 

[rb2013]

  @rb2013 Thank you for sharing that nice unit. It's so tempting. I almost bought it today after reading your post. But on second thought, I'd prefer isolated, individually filtered sockets to minimize possible interference between pc, dac, amp, etc. The Shaffner filters I was considering are also balanced filters. They have even higher attenuation (above 70dB). I am planning to get a metal case like that and put in 5 filters to cover all my audio related devices. 

Well I suppose if you were extremely worried about this kind of filtering you could add a Shaffner easily to the Art Pro - there is plenty of room inside.  The filter levels of 70 dB for the Shaffner is only a peak reading at very high frequency (300K) and it depends on the impedence levels (see the link data sheet charts).  At certain impedences the filtering is close to zero at 10K rises quickly to 60dB at approx 300K then falls off fairly steeply.
http://www.farnell.com/datasheets/55203.pdf
 
Since Art Pro offers this ground isolation RFI/EMI filtering and CMR, DMR I was thinking of using seperate ones on my DAC and another for the MXU8.  I would love to see what's under the hood on the Shaffners.  What I like about the Art Pro is the use of a discrete design - with several large baluns.  Also several large Carli Polypropylene film capacitors.  I also like the nice quality wiring inside the unit.  With a decent Power Chord to the MX-U8 a really nice improvement in SQ.
 
On Baluns for filtering from this PS Audio Review:
http://www.6moons.com/audioreviews/psaudio3/power.html

The Ultimate Outlet supposedly achieves all this with the help of a small donut-shaped iron core wrapped with heavy-gauge Litz wire called a Balun - balanced/unbalanced transformer. "When an AC signal comes into the balun's two wrappings of wire," the PS Audio website explains, "the balanced design cancels out anything in common to the two wires. Unlike series filters that only work on noise over a specified frequency range, a well-designed balun cancels all noise at all frequencies. Yet, due to the small number of wire turns, it does not restrict power as a conventional power conditioner would."


"The Ultimate's balun," it continues, "reduces common mode noise by up to 40dB, meaning that whatever noise is on the line will be reduced by over 100 times, and [it] also handles differential noise. This major cleaning effort takes place at virtually all frequencies, not only at the very high frequencies attended to by typical power filters or conditioners."

 
BTW: Running three separate MX-U8's now - at various stages of mods.  One with the HW caps and another with the Nichicon Fine Golds.  So far prefering the FGs. They are taller and have to be mounted somewhat sideways.  They sound a little sweeter - both a nice improvement over the FCs.
 

 

[Senn-Fi]

I just received my U12 and am connecting from Mac Pro to PS Audio Directstream DAC...
 
It works great with AES/EBU and sounds very good.
 
When I tried I2S with HDMI, however, there is a brief amount of sound from the left channel and then it only plays out of the right channel.
 
If I set JRiver to transcode to DSD over PCM (DoP), it works normally (and sounds great out of both channels).  Anyone else have a similar issue and/or solution?
 
Thanks!

 

[ginetto61]

Or you could just run one of these right before the U12 or MXU8 - I have and the results are excellent and reversible. And relativly cheap.  The Pro version with the Advanced Power Filtering should not be confused with the non-Pro version which will do line by line EMI/RFI filtering.
The Advanced Power Filtering uses both Common Mode and Differential Mode filters, in addition to the EMI/RFI filters.
From Blue Circle on Common Mode Rejection on their excellent and expensive $2,200 BC60X1:
ART PB4x4Pro Power Distribution System with Advanced Power Filtering:
All PRO SERIES models have an additional internal discrete module called APF (Advanced Power Filtering) which filters out digital and dimmer hash as well as any high frequency noise that is above the audio range. Some off-the-shelf add-on modules saturate and lose their filtering effectiveness as the load increases, but by using a high power discrete design we were able to create a filter that stays effective over the full operating range.

By using both Common Mode and Differential Mode topologies in series for the filter design we are able to block virtually all of the unwanted noise that is between the AC line and ground, and also the two sides of the AC line. This has the additional benefit of reducing ground loop problems in your system. High frequency noise currents in particular are highly attenuated in both directions so that any line noise that could be generated by one of your components is not allowed to get back into your main A.C. wiring so if you use a number of PRO SERIES Power Conditioners in your setup, you can distribute and isolate the noisy components from the sensitive components in your system. Additionally, any signals above 10kHz are filtered from the line with over 40dB of attenuation above 100kHz and beyond.

Every PRO SERIES power conditioner is designed with a power capacity of 1800 Watts, surge/spike protection, APF with EMI & RFI filtering, front-mounted unswitched power outlet and an adjustable rear-mounted gooseneck light source for bright illumination behind the rack. The spacing and alignment of the rear outlets to accommodate various size power plugs and AC adapters.

Features:




 
Not bad for $85
 

1. APF - Advanced Power Filtering
2. Power Capacity of 1800 Watts
3. Surge & Spike Protection
4. EMI & RFI Filtering
5. 8 Rear Outlets with Power Adapter Friendly Positioning
6. One Front-mounted Unswitched Power Outlet

Non-pro version of the PB 4X4 with EMI/RFI at the AC and between each AC block ($49) - which the Pro version has in addition to the APS:

 
Hi and thanks a lot for the very valuable suggestion.
Yes i guess some kind of mains filtering could be very beneficial (of course also better regulators like the ones used by Mr Pakultra, maybe even much more.  But i see this mod more difficult and for skilled people)
Instead adding some kind of filter upstream the transformer i think i could do that

 
By the way i have not completely understood what you are proposing.   Is it a off-the-shelf product ?  is it a DIY project ?  do you have some links to this product ?
I am a little obsessed by toroids because i and a friend did some tests trying to build a line preamp.  We tested it with both a toroid and a EI x-former of the same voltage and power in the same power supply.
Switching on/off the lights in the listening room was producing with the volume at medium level a loud pop in the speakers with the toroid, and much much less with the EI.   It was a clear evidence of the superior filtering of spikes of the EI type transformer.
Unfortunately we did not think to try also a mains filter ... that could have been extremely interesting
So if you could please provide some more links to parts and products i would be very grateful.
Thanks again,   gino

 

[rb2013]

   
Hi and thanks a lot for the very valuable suggestion.
Yes i guess some kind of mains filtering could be very beneficial (of course also better regulators like the ones used by Mr Pakultra, maybe even much more.  But i see this mod more difficult and for skilled people)
Instead adding some kind of filter upstream the transformer i think i could do that

 
By the way i have not completely understood what you are proposing.   Is it a off-the-shelf product ?  is it a DIY project ?  do you have some links to this product ?
I am a little obsessed by toroids because i and a friend did some tests trying to build a line preamp.  We tested it with both a toroid and a EI x-former of the same voltage and power in the same power supply.
Switching on/off the lights in the listening room was producing with the volume at medium level a loud pop in the speakers with the toroid, and much much less with the EI.   It was a clear evidence of the superior filtering of spikes of the EI type transformer.
Unfortunately we did not think to try also a mains filter ... that could have been extremely interesting
So if you could please provide some more links to parts and products i would be very grateful.
Thanks again,   gino

Hi Gino,
 
I also share your concern about the toroidal transformers.  I much prefer R-cores, like in my R2R Lite 60 modded DAC project (which has two separate ones - one for the tube gain stage and one for the digital section) - which much more immune to RFI/EMI.  The mechanical fitting of a new transformer into the small box with a Schaffner type filter is a major project - same for building a seperate PS box.
 
The Art Pro - Pro PB 4X4 is a cheap, readily available turnkey solution.  Of course a super regulated linear PS directly to the clocks as Alex is building is optimal.  But that is a tremendous amount of work and risks damaging the unit (very hard to reverse).
 
Now I suppose you could argue that leaves open to RFI/EMI the short power chord run between the Art Pro and the U12 or MXU8.  I would use a good power chord with decent shielding there (most of the better audiophile power chords have heavy shielding).  The Pro PB 4X4 will have filtered 99.99% of the noise and power grunge before that short run (liely very little added noise).  And as Blue Circle points out will prevent your own systems locally generated noise (DAC and USB Clocks for example) of feeding back to you pre-amp, amp or other electronics to create local noise.  I suppose you could find a very short power cable run say 1 foot - to keep possible antenna effects to a min.  But I would say that is bordering on paranoid.
 
The Pro PB 4X4 also adds the benefit of surge protection.
 
Here is the link to the Art Pro -Pro PB4x4 - http://www.ebay.com/itm/181487658681?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
$85 with free shipping.
 
Here is DIY power chord link (explains RFI/EMI shielding):
http://www.venhaus1.com/diymains.html
 
This is a simple plug and play solution - that allows one to move on to improving other parts of their system.
 
I have to say the sound quality with the FG caps in the MXU8 and the Pro PB4X4 is amazing compared to stock.  And I was already using a Monster power filter and a Richard Gray Pro 400.  My systems have never sounded better.
 
Good luck!

 

[abartels]

 
Well I suppose if you were extremely worried about this kind of filtering you could add a Shaffner easily to the Art Pro - there is plenty of room inside.  The filter levels of 70 dB for the Shaffner is only a peak reading at very high frequency (300K) and it depends on the impedence levels (see the link data sheet charts).  At certain impedences the filtering is close to zero at 10K rises quickly to 60dB at approx 300K then falls off fairly steeply.
http://www.farnell.com/datasheets/55203.pdf
 
Since Art Pro offers this ground isolation RFI/EMI filtering and CMR, DMR I was thinking of using seperate ones on my DAC and another for the MXU8.  I would love to see what's under the hood on the Shaffners.  What I like about the Art Pro is the use of a discrete design - with several large baluns.  Also several large Carli Polypropylene film capacitors.  I also like the nice quality wiring inside the unit.  With a decent Power Chord to the MX-U8 a really nice improvement in SQ.
 
On Baluns for filtering from this PS Audio Review:
http://www.6moons.com/audioreviews/psaudio3/power.html
 
BTW: Running three separate MX-U8's now - at various stages of mods.  One with the HW caps and another with the Nichicon Fine Golds.  So far prefering the FGs. They are taller and have to be mounted somewhat sideways.  They sound a little sweeter - both a nice improvement over the FCs.
 

 
Hi rb2013, welcome back!! 

 

 
Any progress on XO's?
hgpsemaj send me small smd adapterboards which make soldering NDK's a lot easier!
 
http://item.taobao.com/item.htm?spm=a230r.1.14.4.SpfRsD&id=19734749250&ns=1&_u=t29sgvbrf20f&abbucket=6&utm_campaign=website&utm_source=sendgrid.com&utm_medium=email#detail
 
I'm waiting for components to start modding MX-U8
 
Regards,
Alex

 

[ginetto61]

Hi Gino,  
I also share your concern about the toroidal transformers. 
I much prefer R-cores, like in my R2R Lite 60 modded DAC project (which has two separate ones - one for the tube gain stage and one for the digital section) - which much more immune to RFI/EMI.  

 
Hi again ! yes it is what i learned reading here and there in tech sites.  They have many quality but they are not that good at filtering noise i am afraid.  Yes the R-core are much better at you know what ? this could be also a nice idea.
I am sure that just replacing the transformer with a R-core could improve mains noise rejection.  I feel that the mains where i live are not very polluted but it depends on the moment of the day.
 

The mechanical fitting of a new transformer into the small box with a Schaffner type filter is a major project - same for building a seperate PS box.  

 
I think that to put these filter in a separate box is also very smart ... and can serve more unit, the converter and the dac for instance. 
 
 

The Art Pro - Pro PB 4X4 is a cheap, readily available turnkey solution.  Of course a super regulated linear PS directly to the clocks as Alex is building is optimal.  But that is a tremendous amount of work and risks damaging the unit (very hard to reverse).
Now I suppose you could argue that leaves open to RFI/EMI the short power chord run between the Art Pro and the U12 or MXU8.  I would use a good power chord with decent shielding there (most of the better audiophile power chords have heavy shielding).  The Pro PB 4X4 will have filtered 99.99% of the noise and power grunge before that short run (liely very little added noise). 
And as Blue Circle points out will prevent your own systems locally generated noise (DAC and USB Clocks for example) of feeding back to you pre-amp, amp or other electronics to create local noise.  I suppose you could find a very short power cable run say 1 foot - to keep possible antenna effects to a min.  But I would say that is bordering on paranoid.
The Pro PB 4X4 also adds the benefit of surge protection.
Here is the link to the Art Pro -Pro PB4x4 - http://www.ebay.com/itm/181487658681?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
$85 with free shipping.  

 
Thanks but sadly no shipping to Norway. I am in Norway now.  When shipping is available from USA the products usually end at a double price (for cheap products i mean).
Instead from HK or China often free shipping and no customs --- i do not know why ...
 

Here is DIY power chord link (explains RFI/EMI shielding): http://www.venhaus1.com/diymains.html
This is a simple plug and play solution - that allows one to move on to improving other parts of their system.
I have to say the sound quality with the FG caps in the MXU8 and the Pro PB4X4 is amazing compared to stock. 
And I was already using a Monster power filter and a Richard Gray Pro 400.  My systems have never sounded better.
Good luck!

 
Very interesting.  I think that at least the caps i will do for sure.  I have also a new desoldering gun never used.  It is time to solder something.  I have also a nice 2%Ag alloy ... low this alloy. I have never had a cold joint ... and i am a dog at soldering indeed. 
If you happen to see something from China that could work similarly to the Art unit you mention i will buy it immediately. 
Thanks again.
Kindest regards,  gino   
 
P.S.  there is a new thread specifically about the Melodious ... i think you could post there the mods on your Melodious converter
i jump from this thread to the other because i have both (actually i have also the old Gustard U10)
My feeling is that the Melodious is a little better unit than the Gustard, but also more expensive.  
A modded Gustard by the way could be superior to a stock Melodious ... but i do not know for sure. 

 

[prot]

rb2013 that's a cool filter, especially for the price.

Anyone who knows a comparable EU device ?

I was looking at https://www.youtube.com/watch?v=9mE-N1Ll6o8 but I find the €600 price exaggerated.

To answer my own Q, the ART devices are available in EU and for a very good price. Just have to work with IEC coonectors
http://www.bax-shop.de/art-pb4x4-power-base-stromverteiler-und-stabilisator

 

[rb2013]

   
Hi rb2013, welcome back!! 

 

 
Any progress on XO's?
hgpsemaj send me small smd adapterboards which make soldering NDK's a lot easier!
 
http://item.taobao.com/item.htm?spm=a230r.1.14.4.SpfRsD&id=19734749250&ns=1&_u=t29sgvbrf20f&abbucket=6&utm_campaign=website&utm_source=sendgrid.com&utm_medium=email#detail
 
I'm waiting for components to start modding MX-U8
 
Regards,
Alex

I'm still having issues getting the Crystek CCHD-957 to work in the MX-U8 - I have another U12 coming - I will try them there.
 
Those boards are the ticket - it would be nice if NDK (or DIYINHK) and Crystek would just make a standard through the hole pin version - like all these Chinese TCXO clocks.  Then with a socket like I have it would be a simple matter of plug and play.  The Clocks would already be tested and ready to mount.
 
Look at issues you had with shorting out the LME on the MX-U8 with the clock swap.  What a PIA.
 
Maye one day they'll be like opamps with many swappable designs - and we can all easily clock roll!