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In Reply to: RE: Ferrite/cap filter on the P24: next best thing too a full linear cMP setup? (interim report) posted by theob on August 08, 2011 at 06:43:39
Hi Theo,Good too hear you found a new mobo and have it up and running again.
I’m not sure if I correctly understand your questions (and thoughts behind the questions) too provide a useful answer. Some things puzzle me.
> If you can count the caps in the atx power supply all you need are the ferrites over the 5 v and ground lines etc and then the cap in the p24 connector on the mobo.<
* I don’t know if you can assume that the caps inside the ATX PSU will act as being a part of the 3 order filter on the P24 line. May be it works this way, may be it doesn’t. I just don’t know.
So just too be sure, I don’t consider the caps inside the ATX too be a part of the 3 order filter. So I use xxtra caps with the right values too create a 3 order filter. Since we are targeting (V)HF, caps with low ESR and excellent VHF characteristics are important.> all you need are the ferrites over the 5 v and ground lines etc <
Why do you think this? I see 2 problems with this.* (V)HF AC pollution travels from the ATX onto the MoBo on all DC plus voltage P24 lines.
You may prevent (V)HF AC pollution travelling on the +5 voltage onto the MoBo, but (V)HF polution than will simply travel onto the MoBo through the other positive DC voltage lines (+ 12, -12, +3,3, 5V stand-by, Power-OK) and return through the combined ground too the ATX.
A clean and steady ground is equally important. ‘Zero’ and ‘Ones’ are recognized as a voltage difference compared too ground. So both supply voltage and ground have too be ripple free. Both are of equal importance. Also the clocks on MoBo and Soundcard are very sensitive too (V)HF polution on supply and ground.
It is even important too prevent (V)HF traveling through the SSD ontoo the MoBo.
I also use a 3 order filter on the power lines too the SSD. And also this give a little SQ improvement.
See photo.
Van on filtering, demping, ect * How do you avoid DC bias in the ferrites (saturation of the ferrites)? The magnetic flux produced by DC plus and DC minus currents through the ferrite have too be equal too avoid saturation of the ferrites through a DC bias.
It’s not clear too me how you know that the magnetic flux produced by the % volt DC + and DC - minus return currents on the black wires will cancel out each other in the ferrite. The ferrites will saturate and loose there effect if no attention is paid too DC bias. Currents on the P24 are high. See my P24 measurements. Almost 1 amp for the combined +5 volt lines. Most ferrites saturate when there is more than 0.4 amps applied on them. I think one can easily go wrong when just grabbing the 5 volt lines and a some black ones.> Or you can use a p24 extension to push caps in the extension connector, ferrites on the extension line and caps pushed into the connector into the mobo. Which way did you do it? <
Back in may 2011 I just pushed caps into the connectors of the MoBo and/or connectors on the P24 extension cable. I did that too quickly verify if a 2nd or 3thrd order with ferrites + caps would have some effect.
By now I have soldered the caps onto the P24 extension cable connector. I cut away the plastic on the side of the P24 connector on each side, this way it's easily solder the caps onto the small metal parts inside the plastic connector. See photo.
Van on filtering, demping, ect > Now on my new mobo I have caps into the p24 connector for the 5 and 12 volt lines, ferrites on the wires...very little improvement <
With only a few ferrites clamped on the P24 In my situation there also was very, very little improvement. As I posted before at least 6 or 7 ferrites on ALL P24 wires are needed to make SQ improvement that is worth the trouble. But one only gets a real nice significant (!) sound quality improvement when creating a 3 order filter through adding caps in front and after the ferrites. I used 7 ferrites which clamp around ALL P24 wires (thus no DC bias) See picture.
Van on filtering, demping, ect
I tried this cap-ferrite-cap filter on the Antec Earthwatts ATX and on the 2 Pico’s I use. In all 3 situations I got the same sound quality improvement. Attention: same amount means: the pico 160-xt with P24 filter still sounds better with the filter than the Antec with the filter.So my experience with using ferrites so far is:
* ALL power lines coming from a switching PSU need filtering
probably all lines coming from a switching PSU are polluted with (V)HF noise. All these lines need filtering to prevent (V)HF travelling ontoo the MoBo and back through the ground too the switchting PSU.* As the author on the www.audiosystemsgroup.com pointed in his white papers on the use of ferrites : just a few ferrites will have no effect. You need at least 7 too 8 too create enough impedance too get past the threshold effect (see the white papers)
* A very nice sound quality improvement is realised when also caps are used too create a 2nd or 3thrd order filter
But a 3thrd order filter with ferrites is only effective from 1mHz and up. I also want too filter the 300 kHz switching noise (and it’s harmonics.) So I also need something too filter these frequencies.
So right now I’m experimenting with 10mH ferrite chokes + caps on the P4 lines and the 12V power line too the Pico 160-XT. And whow (!) this also makes a very nice SQ improvement. I simply use the ferrite chokes which are inside these little noise filters. See picture. They are very cheap 3,50 euro’s. And I can easily solder P4 connectors and caps too them.
Van on filtering, demping, ect It sounds really good. Thankx too audiodan I got this idea. More too come on these extra filters. I need more time for experiments and listening.
fully optimized cMP2 PC -> ESI Juli@ -> Van den Hul Optocoupler MkII-> Lavry Black DA10 -> XLR Mogami Gold -> Klein & Hummel O300
Edits: 08/10/11Follow Ups:
Mark I am interested is seeing a better picture(if its not too much trouble) of where you cut some plastic off the P24 extension connector to solder caps. I've gotten my extension cables and I need to solder some caps onto it.I've got some caps stuffed into it and so now I have a true pi filter which does do a better job of filtering but the stuffing is getting crowded.
Sonics so far: less bright and a lot less edgy on some music files...better dynamics but a bit of a lower mid upper bass suckout (which I easily fixed with my crossover points/volume settings). Net/net better sonics after all the adjustments.
Edits: 08/13/11 08/13/11
Hi Theo,
Here’s a picture.
Van on filtering, demping, ect
Although since I’m using a very small SilverStone SST-ML03B HTPC-case for already 4 months now, I still have still plenty of room inside the case for the P24 with 7 ferrites for ribbon cables clamped onto the P24 extension cable.
I use another P24 extension cable (with 3 extra black square ferrites on it. More is always better :-) ) too reach the P24 connector on the MoBo again. This way the P24 with flat-ferrites can be laid on the bottom of the case in parallel with the MoBo. Using this extra P24 extension cable allows me too efficiently use the space that is in front of the mobo. See picture.
Van on filtering, demping, ect
Mark
fully optimized cMP2 PC -> ESI Juli@ -> Van den Hul Optocoupler MkII-> Lavry Black DA10 -> XLR Mogami Gold -> Klein & Hummel O300
It looks like you got a real clean cut on the plastic which I have not been able to do. Hate to keep bugging you but what kind of tool did you use?
Hi Theo,I used such a knife. I think in the US they are also called ‘Stanley knife’
Van on filtering, demping, ect The trick is: first cut in at all 4 corners.
Van on filtering, demping, ect You than make a cut on the inside along the sides like this.
This way you separate the plastic outside from the inner plastic deviding sections.
Van on filtering, demping, ect
After that, you can cut off the plastic strip on both sides. Take it easy. You may need a few strokes too finally cut all the way through the plastic on the side. See picture.
Van on filtering, demping, ect Mark
fully optimized cMP2 PC -> ESI Juli@ -> Van den Hul Optocoupler MkII-> Lavry Black DA10 -> XLR Mogami Gold -> Klein & Hummel O300
Edits: 08/13/11
Ok Stanley did the trick. I had bought 2 p24 extensions one was in cmp^2 with caps stuffed here and there and ferrites galore. As reported it sounded good. So in the process of operating on the other p24 cable to have access to the metal .. for soldering I shut the system off and pulled a few of the caps off the p24 in the sys (to solder them on the other p24). When I turned the system back on it sounded dull and grainy and closed down. I missed the caps...even though it was only temporary. Anyway once I fitted the spare p24 with soldered caps and ferrites and put it back in the system I was not prepared for the sq pop. Wow very, very nice! I finally see what you were saying Mark. Sound space bigger, deeper highs quick but integrated with the mids (hard to accomplish imo). And the bass was so much richer,deeper and tuneful. Its one of those things where everything sounds great. I played all my favorites and they never sounded better.A smashing success...thanks again Mark!!!
Edits: 08/14/11
Hi Theo,
Good too hear you finally got results!
Did you also put a filter on the P4?
Cleaning the power too the P4 will also result in better sound quality.
Cleaning the power of the P4 with this type of filter is very easy.
- Take a P4 extension cable and 1 or 2 ferrites.
- make 4 or 5 turns around the ferrites (as many turns as the length of the P4 extension cable allows)
- put caps before and after the ferrites.
And again you will have a very nice sound quality improvement!!
Mark
fully optimized cMP2 PC -> ESI Juli@ -> Van den Hul Optocoupler MkII-> Lavry Black DA10 -> XLR Mogami Gold -> Klein & Hummel O300
Yep I did it already...it is a nice improvement. Thanks again.
I'm starting to think that my implementation of the stuffed capacitors into p24 connectors was seriously handicapped from sounding right. There is so much better sound from the soldering that I believe my pushing of the caps into the p24 slots was not making proper contact or intermittent contact at best. Anyway for those who want to try this my recommendation is don't stuff, solder right from the beginning.
Again a big shout out to Mark for this excellent tweak!!
perfect...thanks again!
thanks
Hi Mark and welcome back from holiday.
'.....(V)HF AC pollution travels from the ATX onto the MoBo on all DC plus voltage P24 lines.
You may prevent (V)HF AC pollution travelling on the +5 voltage onto the MoBo, but (V)HF polution than will simply travel onto the MoBo through the other positive DC voltage lines (+ 12, -12, +3,3, 5V stand-by, Power-OK) and return through the combined ground too the ATX.
A clean and steady ground is equally important. ‘Zero' and ‘Ones' are recognized as a voltage difference compared too ground. So both supply voltage and ground have too be ripple free. Both are of equal importance. Also the clocks on MoBo and Soundcard are very sensitive too (V)HF polution on supply and ground.
It is even important too prevent (V)HF traveling through the SSD ontoo the MoBo.
I also use a 3 order filter on the power lines too the SSD. And also this give a little SQ improvement.
See photo...'
I realize I have to do all the voltages I was just surprised I did not get a bigger sq improvement on the 5v line, thats all.
'...How do you avoid DC bias in the ferrites (saturation of the ferrites)? The magnetic flux produced by DC plus and DC minus currents through the ferrite have too be equal too avoid saturation of the ferrites through a DC bias.
It's not clear too me how you know that the magnetic flux produced by the % volt DC + and DC - minus return currents on the black wires will cancel out each other in the ferrite. The ferrites will saturate and loose there effect if no attention is paid too DC bias. Currents on the P24 are high. See my P24 measurements. Almost 1 amp for the combined +5 volt lines. Most ferrites saturate when there is more than 0.4 amps applied on them. I think one can easily go wrong when just grabbing the 5 volt lines and a some black ones...'
I don't know if I am avoiding dc bias...as I posted before I use brute force (I now have approximately 10 ferrites on my p24 line...trying to include a black with another color line within a ferrite).
'...By now I have soldered the caps onto the P24 extension cable connector. I cut away the plastic on the side of the P24 connector on each side, this way it's easily solder the caps onto the small metal parts inside the plastic connector. See photo...'
I plan to solder also once I believe I have the right combo of ferrites/caps in the right places. Do you still use 440 uf before the ferrites and 47 uf after (roughly a 10:1 ratio)?
'...So right now I'm experimenting with 10mH ferrite chokes + caps on the P4 lines and the 12V power line too the Pico 160-XT. And whow (!) this also makes a very nice SQ improvement. I simply use the ferrite chokes which are inside these little noise filters. See picture. They are very cheap 3,50 euro's. And I can easily solder P4 connectors and caps too them...'
I would like to see a link to these devices to understand them better. What really baffles me is that with my old mobo I got a significant sq pop but not on my new mobo. Maybe it needs more breakin time, maybe its the difference between an ES2L and an S2L Ga-G31m mobo.
Please hang with me on this. I believe you are getting good sq pops but I alas am not...yet.
Hi Theo,
Yes I still use this 10:1 ratio. But there is no real calculation or knowledge behind this ratio. I just copied values that I red in 2 documents on decoupling (the Murata paper and the Altera paper).
> I would like to see a link to these devices to understand them better. <
Nothing special about these filters. They all have the same schematics and they are widely used. You will find them everywhere. Since they are cheap, it’s an easy way too combine 2 chokes in a handy enclosure onto one can easily solder the PSU wires. I don’t connect them too a real earth. It’s just the chokes I’m interested in. It’s easy too create a 3 order filter with them. I place caps before and after chokes so I can experiment with much higher capacitance values.
Ontstoringsfilter 0,6 A (Conrad Electronic)
http://www.produktinfo.conrad.com/datenblaetter/525000-549999/534625-da-01-en-Printfilter_0_6_A_5500_2000.pdf
On the 12 V DC power line which powers the Pico, I use one which can handle 1,6 amps. On the P4 12 V DC power line I use one which can handle 0,6 amps. I chose hight mH values. The Voltage drop across these filters is about 0,3 – 0,4 Volts. But this is easily corrected through raising the output voltage of the linear PSU’s a little. I’m really amazed that these filters give a profoud positive SQ effect on the 12 V DC power line which powers the Pico. Not in my wildest dreams I would have expected this. It was audiodan who suggested trying this.
7 or 8 ferriets on the 12 V DC power line to the Pico have no effect. I expected this. But I didn’t expect 2 x 6mH chokes + caps placed BEFORE the Pico too have such an effect.
So the last stop, before the top (an all linear PSU) is no longer a hybrid PSU solution (P24: Linear PSU + Pico and a Linear on the P4)
The last stop before the top is: a hybrid PSU solution with heavy filtering. What filters and what way is the most easiest DIY solution, still has too crystallize from experiments. So far I found:
- caps + (much)ferrites + caps give a nice sound quality improvement and is easy to do. But It only effective in the mega Hertz regions.
- The Pico uses the LM2642 chip from National Semiconducter which has switching frequency of 300 kHz. This frequency (and harmonics) should also be filtered. So chokes have too be brought in.
Using ferrite based coupled chokes which can be found in these ready made line filters is an easy way the experiment with chokes in the P4 12 V dc power line.
Too my (big) surprise these filters also had big effect on SQ when placed on the 12 DC power lines that power the Pico on the P24. So cheap linear bench PSU’s (50 – 90 euro’s) may give a nice SQ pop, but the output of cheap linears appears to be very noisy somehow. I see no other explanation for the very significant SQ improvement when ferrites, caps and/or chokes are used on the outputs of a linear.
My overall conclusion is:
A hybrid PSU solution is no longer the last stop before the top (an all linear PSU).
The last stop before the top is: a hybrid PSU with heavy filtering.
I hope other inmates with more skills and knowledge will join these filter experiments.
When done right: ferrits + caps give a real significant SQ improvement, but will not deal with the 300 Khz swithing frequency from the Pico.
> What really baffles me is that with my old mobo I got a significant sq pop but not on my new mobo. Maybe it needs more breakin time, maybe its the difference between an ES2L and an S2L Ga-G31m mobo. <
I’m not a member of the ‘breakin school’. I don’t ‘believe’ in it the way audiophiles handle the subject.
I also don’t think it’s the difference between mobo’s types. I used several brands and types and the difference are very little too none.
I really have absolutely no clou on what is wrong and what might be the cause, as all details about your setup and connections matter very much.
Mark
fully optimized cMP2 PC -> ESI Juli@ -> Van den Hul Optocoupler MkII-> Lavry Black DA10 -> XLR Mogami Gold -> Klein & Hummel O300
Hey Mark ....thanks for the info.
I have several P24 extension cables on order to experiment with. Also I thought about the caps in the antec and there is no reason why they can't be part of 3 order pi filter. But putting in a cap ferrite cap filter on the extension 1st connector/extension wires and extension connector to mobo will be another pi filter in series with the caps (in Antec), ferrites, caps in extension connector. So this combo is probably very effectiver in rfi rejection/dissapation, Anyway I'll continue to work on this.
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