CAPS v2 noise ?

**extracampine** · 03-30-2012, 11:27 AM

Thanks for the ongoing replies.

phofman - I'm not blaming the PC builders per se, but I had been informed that the CAPSv2 is 100% silent.

obt_man - thanks for the comment; for me the noise is an issue, especially as I spent $$$ in order to get a completely silent unit.

Chris - I have not yet managed to find another firewire device to test the theory that the DAC draws more power than expected via Firewire.

Are there any CAPSv2 owners here that have a firewire device they can test by plugging into their CAPS? Would sure be appreciated...!

Thanks

**ted_b** · 03-30-2012, 11:37 AM

which does not use firewire power. The pins are disconnected at the DAC, so there should be no power needs, excessive or otherwise, from the DAC's firewire port.

**extracampine** · 03-30-2012, 12:29 PM

Thanks, v interesting comment. So what is the noise? Should I go ahead and disconnect the SSD to see if that alters the noise, as mentioned above?

The noise only occurs when the firewire cable is plugged in at both ends, even if the DAC is switched off. Obviously if the CAPS is switched off and the DAC is on, there is no noise!

**ted_b** · 03-30-2012, 01:32 PM

pitched noise comes from video display corruption)?? Dunno...

**Miska** · 03-30-2012, 01:56 PM

The noise only occurs when the firewire cable is plugged in at both ends, even if the DAC is switched off. Obviously if the CAPS is switched off and the DAC is on, there is no noise!

Sounds like a grounding issue. Please check what kind of ground connections each device connected to the setup has. Both at the DAC side and computer side.

Good way to ask for trouble over here is to have a computer connected to any equipment that is in turn connected to the cable network...

**extracampine** · 03-31-2012, 05:46 AM

Ok some further testing:

1. All equipment off & connected - no noise

2. Monitor on - no noise

3. CAPS on - no noise initially, then system beep, then some noise when the Windows logo appears, then the continuous noise when the Windows welcome screen and then desktop appear

4. Unplug monitor from CAPS - 1 second pause in noise, then resumes

5. Switch on DAC - 1 second pause in noise, then resumes
6. Switch off DAC - noise continues, no pause
7. Unplug power from DAC - noise stops
8. Plug in power to DAC - 4 second pause, then noise resumes

9. Unplug firewire cable from CAPS - noise stops
10. Plug in firewire cable to CAPS - 2 second pause, then noise resumes
11. Unplug firewire cable from DAC - noise stops
12. Plug in firewire cable to DAC - 2 second pause, then noise resumes

13. Unplug/plug in ethernet cable to CAPS - no change
14. CAPS off - noise stops

To recap, the sound is coming from the CAPS unit - not the DAC, speakers or external power transformer. It is high pitched and a high frequency oscillation from what my ears can pick out.

Hope this helps. Miska what do you mean by grounding?

Thanks!

**Miska** · 03-31-2012, 06:28 AM

7. Unplug power from DAC - noise stops
11. Unplug firewire cable from DAC - noise stops

I'm assuming Weiss has earthed power socket, (7) cuts that connection out. Seemingly the firewire ground/shield is connected to this potential in Weiss, since (11) has the same effect.

Since Classe has also earthed power socket, but to remove the noise you don't need to cut connection or power to Classe? So you are either using balanced cables between the two, with the ground disconnected from the other end (floating configuration), or the unbalanced ground is not earthed at either end.

Now the next question is if there's a ground connection to earth between CAPS chassis/firewire through the PSU power brick? I suspect
1) it is floating, or
2) it is connected, but the CAPS and audio equipment are connected to a different mains feed

Are there any other connections from CAPS to equipment that would use earthed mains than the monitor? (all monitors I've had use mains PE)

Miska what do you mean by grounding?

Most of the signal cables carry ground signal potential. Some equipment connects this to mains protective earth and some don't. This combination can create problems. Ordinary desktop PCs connect the metal chassis to mains protective earth, while many laptop chargers don't, but they keep the power floating. I don't know what is the case with CAPSv2, since it's sort of between the two.

**cjf** · 03-31-2012, 09:44 AM

Focusing attention to the SSD was mentioned twice already in this post by myself and obt_man. Have you tried disconnecting the HD power cable and powering on the PC to see if the noise stops? Obviously the machine won't boot to windows but it would tell you if it has anything to do with the noise you are hearing.

**extracampine** · 04-02-2012, 11:49 AM

Thanks - haven't yet tried disconnecting the SSD. I suspect that I won't hear the noise, as the noise doesn't start until the Windows welcome screen appears, which won't happen if I disconnect the SSD.

I can do it anyway and report results if worthwhile? Would obviously mean opening up the unit which I haven't done yet (not that I'm a technophobe!)

**cjf** · 04-02-2012, 10:13 PM

As an fyi, the only thing that the windows welcome screen signifies is that the hard drive is now in use. The POST screens you see at initial power-on are all handled by the BIOS and the hard drive is not yet in the picture.

The main components that are in play during the POST process before the hard drive are the CPU/RAM,Video card, USB slots and maybe the Firewire card. If the Firewire card is not visible from within the BIOS screen then you can probably rule it out as a possible candidate. If the noise is absent during that initial POST time its unlikely any these devices are the cause of your noise.

So if the noise starts when you see the windows welcome screen this means that your noise could very well be the result of the hard drive coming into the picture.

Of course there are more ways to narrow this problem down further like removing the Firewire card and booting the system to see if the noise still exists.

Next, you can try removing (one at a time) any of the third party SOTOM filters that were installed in the system.

Lastly, you could install a different SATA hard drive that you may have lying around with an old copy of Windows installed on it. It doesn't matter if it Blue Screens during the boot up process as that Blue Screen is your sign that the hard drive is now in use. If the noise is absent while looking at a possible blue screen then you have your answer. It was the original hard drive that was the cause of the noise.

Hope this helps

**extracampine** · 04-03-2012, 04:57 PM

Very useful again, thanks. I will follow up some of those issues. But I come back to the point that the unit should be completely silent, and wonder if there are any other CAPS owners who can connect a DAC via firewire? Surely they exist as I had the impression that the CAPS was popular as was firewire DAC (e.g. Weiss).

The reason I went for the CAPSv2 and got Small Green Computer to make it was to avoid all this....!

**extracampine** · 05-04-2012, 05:57 PM

Thanks for the replies, still working on this. The CAPSv2 noise remains an issue.

I haven't yet managed to find another firewire device to plug in to the CAPS to see if the noise persists, though I plan to visit a local hifi shop with the CAPS to see if they have any other firewire DACS.

I have opened up the CAPSv2 to take a look inside:

I tried to locate exactly where the noise is coming from, but this is difficult. The red circle represents my best guess but I could be wrong.

phofman - thanks for your thoughts about the SMPS chokes producing the noise. It does seem that the noise changes when the CPU works, for example when opening a program. The noise can almost disappear for brief periods (i.e. less than a second) when this happens. I see your comment about the coil, but I could not see one inside the CAPS (see above image)!

As one or two people have mentioned, I tried disconnecting the SSD and booting up. As expected, there is no noise. But the noise never starts until the Windows desktop appears anyway. With the SSD disconnected I just get a message saying "Reboot and select proper boot device". Also, the noise does not SOUND like it is coming from the SSD, though again I could be wrong. If the noise IS related to the hard drive, is it due to the hard drive itself or the effect that it has on the power draw through other parts of the system?

cjf - If I remove the firewire card and reboot, I am almost sure that the noise will be gone. This is because simply unplugging the firewire cable at either end (i.e. CAPS or DAC) stops the noise. So the firewire connection would therefore seem to be a part of the issue. Though again, is it because of extra power draw or something else?

Looking forward to any further help from the CA community on this! Will be so pleased to get it sorted! Many thanks.

**The Computer Audiophile** · 05-07-2012, 03:16 PM

A few more things came to mind while reading the newest post.

1. FireWire drivers. Windows has two or three different options for the FireWire chipset. I would go into Device Manager and change the driver, reboot, listen for noise.

2. What happens if you boot from a CD?

3. Is there a firmware update you haven't tried (motherboard or FireWire card)?

**extracampine** · 05-10-2012, 02:42 PM

Thanks for the ideas Chris. The other firewire drivers that come with Windows did not alter the sound. However, I tried a driver from a third party (Unibrain - ubCore Firewire (Firewire 800 - IEEE 1394b) driver suite) and this significantly reduced the noise. However, when this driver was selected, the driver for my Weiss DAC2 seems to stop working:

I tried reinstalling the Weiss driver, and the driver installs OK, but the DAC2 is still not recognised as long as the Unibrain firewire driver is being used.

I wonder if it's a problem with the Weiss DAC2 driver, as if I select the Windows legacy firewire driver and then disable the DAC2 driver, most of the sound goes away also (though not all of it).

I haven't tried to boot from a CD - the CAPSv2 has no CD drive. I suppose that I could connect an external CD drive (I don't have one) though can't imagine that this would make a lot of difference? I looked into updating the motherboard driver though I wasn't clear on how to do this.

Thanks again!

**fireone** · 05-11-2012, 02:22 AM

Hi extracampine, i went to the oyaide website to find a tech description of the cable you are using. There isn't one that I could find.

But in searching more widely firewire pinouts can come in different formats

FireWire (IEEE1394) bus interface pinout and wiring @ pinouts.ru

Are the alternate cables you tried the same format as the Oyaide , because if they are you would not expect a difference.

It might be worth asking Weiss if their DAC needs power from the firewire card. If it doesn't perhaps a four pin wire might do the trick.

**fireone** · 05-11-2012, 03:45 AM

Cancel earlier q. I don't own a Weiss or firewire stuff but the weiss dac 2 manual says power from the computer is not required yet the cabling would be conducting power at least as far as the connection into the dac. And you should be able to use 4 wire according to this

http://www.weiss-highend.ch/computer...c_playback.pdf

**extracampine** · 05-11-2012, 11:40 AM

Originally Posted by fireone

Cancel earlier q. I don't own a Weiss or firewire stuff but the weiss dac 2 manual says power from the computer is not required yet the cabling would be conducting power at least as far as the connection into the dac. And you should be able to use 4 wire according to this

http://www.weiss-highend.ch/computer...c_playback.pdf

Thanks for your input fireone! But how do I use a 4-pin wire when both the Weiss and the CAPS have 6-pin connectors?

**fireone** · 05-11-2012, 04:08 PM

Originally Posted by extracampine

Thanks for your input fireone! But how do I use a 4-pin wire when both the Weiss and the CAPS have 6-pin connectors?

The way I would do it is to take your cheapest of the cheap firewire cable and use the pin out website I linked before to disable the power wire and if that doesn't work the ground cable. Two ways to do this , tape over the power and ground terminals which you can identify on the top left diagram on the pinout page , Or I would carefully strip off the insulating layers of the cable identify the white one and cut it then cover the ends with electricians tape. Test for noise ,Repeat for black cable if this doesn't work,

I may be able to disconnect the power in software going to the PCI bus on the computer ?Maybe ? I don't know how or if you can do it in software. Lastly I could desolder the power + ground terminal on the firewire card . I gather these cards are pretty cheap if the cables are expensive. Also I would check if the chip on the Firewire is one of the recommended ones by weiss. From memory they recommend Texas and one other but not NEC. Big disclaimer here , this is what I would do on my setup . I would be willing to take the risk with these procedures , but you have to think carefully wether you would , in case of permanent damage being done to expensive things like the DAC.

Also before starting anything everything must be disconnected from the mains. The firewire cable I would work on when its disconnected from everything , and if I was going to work on the card ,I would take it off the motherboard.

**The Computer Audiophile** · 05-11-2012, 04:24 PM

Originally Posted by extracampine

Thanks for your input fireone! But how do I use a 4-pin wire when both the Weiss and the CAPS have 6-pin connectors?

I believe you can try a 6 pin to 4 pin converter and a 4 pin to 6 pin to convert back. I believe this would strip the power leg out.

Based on the advice above I would probably pick up a cheap FireWire cable and cut some wires just to test this solution.

**fireone** · 05-12-2012, 12:41 AM

One other suggestion, although I don't know how it could possibly relate to firewire, but is based on the pictures, the one with the red circle around the heatsink. Is the heatsink firmly screwed down? The screws if they need tightening would be on the other side of the motherboard. I'm reminded of my frustrations with toroidal transformers buzzing when I used to use them as power supplies for diy amplifiers. Sometimes the buzzing could be fixed by tightening the nut and bolt holding the transformer on its mounting, and then again sometimes not.

**fireone** · 05-12-2012, 12:55 AM

One more. Does the firewire pci card have a jumper or switch that allows the option of switching the power off to the cable?

The sotm tx usb has both a switch and a jumper depending on which port the cable is attached to. If you can supply brand and model number of the card we can look this up.

**extracampine** · 06-20-2012, 04:17 PM

There doesn't seem to be any switch on the PCI card. The heatsink seems to be firmly screwed down. It sounds like an electronic rather than a mechanical noise.

I have had some success by updataing the firewire driver, as obtained from the Weiss site. There is still a little noise though it is less, lower pitched and not really noticeable from the listening position. The downside of the latest Weiss firewire driver is that there is no auto-sample rate switching! Hopefully they will update this in the next edition!

**Sam Lord** · 06-23-2012, 02:02 AM

Ok I assume you tried different FW cables. This is most likely a mechanical problem that causes an electrical one. Can you access the firewire lines inside the units? You should check continuity of each of those lines, but especially V+ and ground while both devices are fully off and disconnected from AC power but connected by the FW cable. Also, have you tried linking the two chassis with a wire? Go from a screw head to screw head, anodized surfaces have high resistance, and try that when everything is connected and powered up. If that solves or helps it a lot, your FW ground connection is probably flawed. Good luck.

**fireone** · 06-27-2012, 08:40 AM

Just out of curiosity I looked at your photos again and assumed the big red circle is somewhere near the cpu . Then I googled " buzzing from CPU " and low and behold there are pages of results and where a solution has been found ,its causes are manifold. I was surprised by this because to generate a sound ,something mechanical must be vibrating and there don't seem to be many parts that could potentially move or vibrate around a cpu.

**extracampine** · 08-21-2012, 01:05 PM

Thanks for the further replies, and apologies in the delay of my response - I've been a bit too busy to look into this much recently, though have recently come back to it and plan to try and sort it once and for all! The noise continues to be a problem.

I have now tried using a 4pin to 6pin converter to cut out the power leg of the firewire cable; I have a GoldX firewire cable with 6pin on one end and 4pin on the other; I connected the converter to convert the 4pin end to 6pin, and connected the DAC to the CAPSv2 that way - no difference in the noise unfortunately! Does this definitely eliminate the power leg?

Another interesting finding - I tried connecting using 2 firewire cables, as both the DAC2 and CAPSv2 have 2 firewire ports (one cable is my original cable, the other is the GoldX with converter). With this configuration, the noise is significantly reduced! However, when I try and play music (using Foobar and output device "WASAPI: Speakers (Weiss Firewire IO Audio)), I get the error message "Unrecoverable playback error: Endpoint creation failed (0x8889000F)" and playback fails to start.

Sam Lord - I tried connecting the 2 units via screws with a wire - no change. I'm not sure what you meant by checking continuity of the firewire lines inside the units.

fireone: the firewire card in the CAPSv2 should be the SYBA SD-VIA-FW1E1H PCI FireWire card (I did not check when I opened the device though). In device manager it is listed as "1394 OHCI Compliant Host Controller (Legacy)".

Miska - the Classe amp is connected to the DAC2 via balanced (XLR) outputs. Disconnecting the XLR cables from the DAC2 does not alter the noise. The CAPS is connected to the mains via the Seasonic 60W power supply, connected to the monitor via VGA and the NAS via ethernet cable.

Thanks

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Thanks for the ongoing

Chris and OP, just saw this. he is using the Weiss DAC2

Thanks, v interesting

have u tried disconnecting the monitor (sometimes high

The noise only occurs when

Ok some further testing:

7. Unplug power from DAC -

Focusing attention to the SSD

Thanks - haven't yet tried

As an fyi, the only thing

Very useful again, thanks. I