[SodaBoy]

Interesting article on the Belkin PF60:
 
http://archimago.blogspot.ca/2014/02/measurements-belkin-pureav-pf60-power.html

 

[abartels]

  Interesting article on the Belkin PF60:
 
http://archimago.blogspot.ca/2014/02/measurements-belkin-pureav-pf60-power.html

 
I would say, grab some of Ebay, they go for about $200 once in a while, and compare sq.
 
I have Schaffner filters (1A) in both my pre-amp and dac, and both devices sounding better when connected to PF50
Even my mosfet power-amp sounds better when connected to high-current output on PF50, no decrease in dynamics!
 
But, I suppose it is heavily dependent on your home situation, if you have relative clean power, you would definitely have less increase in sq.
I live in an appartment complex where power is dirty. In my case it does a very good job, not to say it is my best investment ever,,,,
 
Also it is very convenient that this device has dipswitches at the back where you can set delay for all the banks (5 for PF50 and 6 for PF60).
With those delay settings I can power on all source devices BEFORE powering on power-amp, and, power off power-amp before powering off source components.
 
My server 2012R2 ControlPC doesn't power off, you can set this per bank.
 
 
Not trying to get you guys buying a powerfilter, it's just that my set indeed does benefit a lot from this unit, and so does a friend of mine which bought the same device.
 
 
Cheers

 
Alex 

 

[ginetto61]

Hi just to add my usual trivial thought

i think that the bigger effort should be done to get a very clean source signal.
This signal is the end what will be amplified by the following amp stages. Trivial i know ...

IMH experience if the source is very good almost any decent amp/speakers combination can sound at least satisfying.
Just an example.
I had a bad sounding cd player.   After substituting other components just out of curiosity i put a plastic turntable with a cheap Nad phono stage in place of the cd player.
I was amazed how much more musical the whole system was sounding ... i am sincere.
So the real problem impacting the whole performance was not the system but the source.
These days i am committed to get a "musical" digital sound out of wav files using a pc.
I can tell you that this is not that easy at all.   Just a detail can ruin the whole picture.
In my opinion the usb to spdif converters can be key units to build up a nice sounding system with almost any pcs.
If the spdif signal out of them is good quality than any decent dac will do the rest.  And even cheap decent dacs can be found.
 
Speaking of the U12 i think i have solved the usb port issue with an external usb power supply in a decent way.
Now i have still some issues open:
 
1)   usb cable quality (i could have jitter in the usb transmission)
2)   filtering of the mains entering the U12.
 
Regarding point 1) i am trying different solution for the usb cable (for instance taking out ferrites could improve the sound).
 
Regarding point 2) after a lot of thinking, given that, as someone rightly has pointed out, the current drawn by the U12 is very very little (around 0.1 A max ?)  i  would really like to try the " chokes " solution, because the common EMI filters are specified for much higher currents and could not be that effective with smaller currents (

)
 
I see many cheap chokes on ebay but i have no clue of:
1)   which model to buy
2)   how to connect it to get a nice mains noise filtering upstream the toroidal.
 
I see chokes used often also in dvd player and other digital players.
Could someone direct me to some pages explaining how to wire these chokes ?
Thanks a lot indeed for all the very very interesting disclosing of tech advice.
Kind regards,  gino

 

[rb2013]

More information on power filters:
 
This relates to the circuit protection feature:
http://audioshark.org/archive/t-1572.html

The least offensive surg protectors seem to be the ones that use (i think this is what it's called) MOV technology.

Here some info on MOV.....

A metal oxide varistor consists of a bulk semiconductor material (typically sintered granular zinc oxide) that can conduct large currents (effectively short-circuits) when presented with a voltage above its rated voltage. MOVs typically limit voltages to about 3 to 4 times the normal circuit voltage by diverting surge current elsewhere than the protected load. MOVs may be connected in parallel to increase current capability and life expectancy, providing they are matched sets (unmatched MOVs have a tolerance of approximately ±20% on voltage ratings, which is not sufficient).

MOVs have finite life expectancy and "degrade" when exposed to a few large transients, or many more smaller transients. As a MOV degrades, its triggering voltage falls lower and lower. If the MOV is being used to protect a low-power signal line, the ultimate failure mode typically is a partial or complete short circuit of the line, terminating normal circuit operation.

If used in a power filtering application, eventually the MOV behaves as a part-time effective short circuit on an AC (or DC) power line, which will cause it to heat up, starting a process called thermal runaway. As the MOV heats up, it may degrade further, causing a catastrophic failure that can result in a small explosion or fire, if the line current is not otherwise limited. An undersized MOV fails when "Absolute Maximum Ratings" in manufacturer's data-sheet are significantly exceeded.

MOVs are often connected in series with a thermal fuse, so that the fuse disconnects before catastrophic failure can happen. When this happens, only the MOV is disconnected. A failing MOV is a fire risk, which is an original reason for the National Fire Protection Association's primary concern is protection from fire.

When used in power applications, MOVs usually are thermal fused or otherwise protected to avoid persistent short circuits and other fire hazards. In a typical power strip, the visible circuit breaker is distinct from the internal thermal fuse, which is not normally visible to the end user. The circuit breaker has no function related to disconnecting an MOV. A thermal fuse or some equivalent solution protects from MOV generated hazards.

If a surge current is so excessively large as to exceed the MOV parameters and blow the thermal fuse, then a light found on some protectors would indicate unacceptable failure. Even adequately sized MOV protectors will eventually degrade beyond acceptable limits, with or without a failure light indication. Therefore, all MOV-based protectors intended for long-term use should have an indicator that the protective components have failed, and this indication must be checked on a regular basis to insure that protection is still functioning.

Now these M.O.V (Varistor) are the circular shaped devices colored yellow, red or blue you see on the circuit boards of these power filters.  They do degrade over time, as they are exposed to power spikes.  So the power filter/circuit breaker or the MOV's should be changed out every few years to maintain their proper functioning.
 
In the simpler design of the Art Pro Pro PB 4x4 really no big deal - on these more complex units a bigger project. Also you may want to avoid buying units that are more then a few years old and have had steady use.
 
More info on MOVs from Audience Adept Response:

Of the power conditioning products on the market today few allow your playback system to attain full dynamic range or reproduce subtle dynamic contrasts accurately. The other culprit afflicting most power conditioning products is the ubiquitous MOV. (Metal Oxide Varistor) The MOV is a sacrificial device. This means it wears down over time until it fails completely. Its purpose is to clamp high voltage transients safely to ground instead of through your equipment. This would be fine if it didn’t break down and behave like the world's worst capacitor across your power line, storing energy and releasing it as performance robbing, time delayed distortion into your audio system. The effect is quite audible. For surge protection the Adept Response employs a non-wearing type high voltage transient suppression.

Adept Response uses only the finest conducting, filtering and transient suppression components. Even the power switch is exceptional, a very high quality magnetic circuit breaker. The advantage over thermal circuit breakers is that thermal breakers increase in resistance as power demand increases, causing heat dependent, resistive modulation of the incoming voltage. This effectively reduces the power available to your equipment just when you need it most. The design employed in the Adept Response provides for the most natural flow of music.

 
Would love to see what's under those Schaffner silver covers.  Hopefully no MOVs just Baluns. 
 
PS I wouldn't and don't use any of these kind of power conditioners with equipment that draws high current - like my class A SS amps.  Especially a dynamic or transient load.  For those I use the RGPC's.

 

[rb2013]

  Hi just to add my usual trivial thought

i think that the bigger effort should be done to get a very clean source signal.
This signal is the end what will be amplified by the following amp stages. Trivial i know ...

IMH experience if the source is very good almost any decent amp/speakers combination can sound at least satisfying.
Just an example.
I had a bad sounding cd player.   After substituting other components just out of curiosity i put a plastic turntable with a cheap Nad phono stage in place of the cd player.
I was amazed how much more musical the whole system was sounding ... i am sincere.
So the real problem impacting the whole performance was not the system but the source.
These days i am committed to get a "musical" digital sound out of wav files using a pc.
I can tell you that this is not that easy at all.   Just a detail can ruin the whole picture.
In my opinion the usb to spdif converters can be key units to build up a nice sounding system with almost any pcs.
If the spdif signal out of them is good quality than any decent dac will do the rest.  And even cheap decent dacs can be found.
 
Speaking of the U12 i think i have solved the usb port issue with an external usb power supply in a decent way.
Now i have still some issues open:
 
1)   usb cable quality (i could have jitter in the usb transmission)
2)   filtering of the mains entering the U12.
 
Regarding point 1) i am trying different solution for the usb cable (for instance taking out ferrites could improve the sound).
 
Regarding point 2) after a lot of thinking, given that, as someone rightly has pointed out, the current drawn by the U12 is very very little (around 0.1 A max ?)  i  would really like to try the " chokes " solution, because the common EMI filters are specified for much higher currents and could not be that effective with smaller currents (

)
 
I see many cheap chokes on ebay but i have no clue of:
1)   which model to buy
2)   how to connect it to get a nice mains noise filtering upstream the toroidal.
 
I see chokes used often also in dvd player and other digital players.
Could someone direct me to some pages explaining how to wire these chokes ?
Thanks a lot indeed for all the very very interesting disclosing of tech advice.
Kind regards,  gino

Funny you mention chokes - that is what the Richard Gray Pro 400's are - massive chokes!  Each unit weighs 20 lbs and has over 1000 feet of wire surrounding its core.
 
The importance of this choke filtering has several aspects:

 Q – HOW DOES THE RGPC DUAL SURGE SUPPRESSION SYSTEM WORK?

Answer
• The RGPC giant “choke” (weighs 20 lbs and has over 1000 feet of wire surrounding its core) is the first line of defense.
• It is designed to place a very low resistive load in parallel with the line as protection against all spikes that usually appear as DC-based, short-term pulses.
• With additional RGPC units star-clustered in parallel within a circuit, the resistive load becomes lower still and surge suppression becomes even more effective.

Q – HOW DOES THE GIANT RGPC “CHOKE” PROTECT ITS INTERNAL MOV?

Answer
• By analogy to football, an RGPC unit has a 500-pound tackle (huge inductor) protecting the quarterback (MOV). Without RGPC parallel surge suppression technology leading interference, the spike would have been passed along the line to do its dirty work.
• RGPC technology protects the on-board MOV as well as your sensitive electronics from destruction by absorbing spikes and noise before they get to any level high enough to cause the triggering of the MOV. Only in the RGPC does the MOV not self-destruct, rather, it throws the surge over to blow the internal in-line fast-blow fuse.

So this massive choke acts as a filter and protection of the MOV inside.

 

[ginetto61]

Funny you mention chokes - that is what the Richard Gray Pro 400's are - massive chokes!  Each unit weighs 20 lbs and has over 1000 feet of wire surrounding its core.
The importance of this choke filtering has several aspects:
So this massive choke acts as a filter and protection of the MOV inside.

 
Hi and thanks again for the very interesting information. You have given material to study for the weekend 

Actually i was thinking to something more like this .... something tiny
 

 
given that the current is very low they should work ok.  But i need a part and a working schematic.
I will look for it.  Maybe in some datasheet there are application notes ?
Thanks again,   gino 

 

[rb2013]

   
Hi and thanks again for the very interesting information. You have given material to study for the weekend 

Actually i was thinking to something more like this .... something tiny
 

 
given that the current is very low they should work ok.  But i need a part and a working schematic.
I will look for it.  Maybe in some datasheet there are application notes ?
Thanks again,   gino 

I would contact John Tucker over at Exemplar Audio - he is genius when it comes to using internal choke PS filters.  He mods audio gear - once did an amazing job on a Denon 5910 SACD player for me - used something like four internal shunts and chokes as well as a bunch of other mods.  You could ask him - really nice fellow.
 
Check out his tubed Oppo 105

 
http://www.exemplaraudio.com/digitalplayertub.html
 
Good Luck!

 

[ginetto61]

I would contact John Tucker over at Exemplar Audio - he is genius when it comes to using internal choke PS filters.  He mods audio gear - once did an amazing job on a Denon 5910 SACD player for me - used something like four internal shunts and chokes as well as a bunch of other mods.  You could ask him - really nice fellow.
 
Check out his tubed Oppo 105

 
http://www.exemplaraudio.com/digitalplayertub.html
Good Luck!

 
Hi and thanks for the suggestion.  Yes the Oppo must be fantastic. I read that even in stock form is already great.
But when i will be done one day with my job i have promised myself to study more the subject.  I would like to start from cheap units/kits and squeeze some drops of better sound out of them with simple mods. 
I have the feeling that some cheap products have an enormous potential.   And i am now obsessed with these usb to spdif converter.
I would buy also the Tanly that seems ready without need of any mods if i could understand the site (Chinese is not my language and i guess the Taobao site is mainly for Chinese customers, sadly).
Regards,  gino   

 

[rb2013]

   
Hi and thanks for the suggestion.  Yes the Oppo must be fantastic. I read that even in stock form is already great.
But when i will be done one day with my job i have promised myself to study more the subject.  I would like to start from cheap units/kits and squeeze some drops of better sound out of them with simple mods. 
I have the feeling that some cheap products have an enormous potential.   And i am now obsessed with these usb to spdif converter.
I would buy also the Tanly that seems ready without need of any mods if i could understand the site (Chinese is not my language and i guess the Taobao site is mainly for Chinese customers, sadly).
Regards,  gino   

I have had tremendous success with my extensive R2R DAC Mod Project.  Way beyond my expectations - really rivaling my APL DAC that cost 4X as much and some ways it's better.
http://www.head-fi.org/t/740362/lite-dac60-pcm1704-r2r-tubed-dac-mod-project.
 
Yes the Tanly intrigues me as well - but won't buy it without some kind of guarantee (this 7 day thing doesn't cut it).  Not after my experiences with the Melodious MX-U8.
Modding is a really fun hobby and is not that difficult if you're just up grading components.  When it comes to actually changing the circuits - well that's another matter.  I trust the professional audio engineers who designed the unit to do that.  This second guessing of their designs is not for me. 
 
I understand their use of medium quality parts for profitability - so there can be better SQ with the best ones swapped in.  Certainly caps - especially film caps.

 

[ginetto61]

 
I have had tremendous success with my extensive R2R DAC Mod Project.  Way beyond my expectations - really rivaling my APL DAC that cost 4X as much and some ways it's better.
http://www.head-fi.org/t/740362/lite-dac60-pcm1704-r2r-tubed-dac-mod-project. 
Yes the Tanly intrigues me as well - but won't buy it without some kind of guarantee (this 7 day thing doesn't cut it).  Not after my experiences with the Melodious MX-U8.
Modding is a really fun hobby and is not that difficult if you're just up grading components.  When it comes to actually changing the circuits - well that's another matter.  I trust the professional audio engineers who designed the unit to do that.  This second guessing of their designs is not for me.  
I understand their use of medium quality parts for profitability - so there can be better SQ with the best ones swapped in.  Certainly caps - especially film caps.

 
For now my main goal is to get a nice AES signal out of the pc.  I have 3 dacs that have this input and i would like to try them in the best conditions befor go hunting for something else. 
I will read your thread. But i need time .. Thanks again,  gino 

 

[rb2013]

   
For now my main goal is to get a nice AES signal out of the pc.  I have 3 dacs that have this input and i would like to try them in the best conditions befor go hunting for something else. 
I will read your thread. But i need time .. Thanks again,  gino 

Well when you get time as my thread goes into detail on the issues with modern Delta-Sigma and Multibit DAC chip designs.  The 'old school' resistor ladder or R2R may still be the best DAC design when all is said and done.  Much has been written on the PCM 1704K DAC chips and they're still being used to great effect - see the Audio-gd Ref 10.32 DAC.
 
Do your DACs handle I2S - as that may be a better digital signal transfer method.  Both SPDIF (RCA and AES) specifications have some issues (impedance matching being very important). 
 
Did the issue on these XMOS based interfaces (Gustard, Melodious and Tanly) of channel swapping on the HDMI/RJ45 outputs ever get resolved?

 

[prot]

Interesting USB noise measurements
http://archimago.blogspot.ca/2015/05/measurements-corning-usb-3-optical.html

 

[ginetto61]

You know what ? I really wonder how an U12 could sound with something like this 
 
http://www.ebay.com/itm/115V-230V-30W-R-Core-Transformer-9V-9V-for-Headphon-amp-preamp-/291473766433?pt=LH_DefaultDomain_0&hash=item43dd30b821
 

 
in the place of the stock one ...
 

 
maybe just that R-core would be the ticket for really good sound.  
It would stop a lot of the noise in the mains.  The usb port can be isolated in some way.
I would be really curious but i should buy another case ... i am thinking seriously to go on with the buy.
 
Instead i bought this ... by instinct ... 
 
http://www.ebay.com/itm/261491990376
 

 
9V+9V/30VA ... now the problem will be to fit it in the small U12 box ... 
but it should have separation between primary and secondary windings ... that is the kind of transformer that i would like to see in place of those **** of toroidals 
I had to try something 
Regards,  gino 

 

[Sonic Defender]

 
9V+9V/30VA ... now the problem will be to fit it in the small U12 box ... 
but it should have separation between primary and secondary windings ... that is the kind of transformer that i would like to see in place of those **** of toroidals 
I had to try something 
Regards,  gino 

Gino, I am interested to know how you have come to the conclusion that toroidal power supplies are so bad? I mean you can find them in gear costing tens of thousands of dollars. How on earth can they be such a problem if designers of cost is no object gear still use them? I'm not at all trying to attack you as you seem like a very nice and always polite poster here, but I'm not sure where the evidence for this dislike comes from? I'm no expert at all so perhaps there is evidence that they actually sound worse (not measure worse, I don't care about measurements that I can't hear).

 

[korn-fi]

  can I know where to get a updated tanly audio usb with spdif output ?

you can visit http://item.taobao.com/item.htm?_u=2qet21bd67b&id=40193288881