• Registered: 2020-09-18
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Topic: Adi2 dac high pitch noise with RCA when play dsd256

When I try to play some dsd256 through foobar.
I notice when I use RCA output, there is very annoying high pitch noise. After I stop the music, the noise disappear.
Then I try dsd128, pcm 384, dsd 64. the noise become less and less.
Playing something like 44k and 96k doesn't have this problem.
I try to connect RCA to different devices but still.
Turning volumn doesn't help at all.
Switching dsd direct doesn't help.

The XLR is totally normal at whole time.

Can anyone give me some ideas about this issue?

2 Reply by KaiS (edited by KaiS 2020-09-18 06:50:46)

  • KaiS
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Re: Adi2 dac high pitch noise with RCA when play dsd256

Is it the same on left and right channel?
What's on the headphones out?
What happens if you use the lowest "Reference Level"?

Which devices did show the problem?

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  • Registered: 2020-09-18
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Re: Adi2 dac high pitch noise with RCA when play dsd256

KaiS wrote:

Is it the same on left and right channel?
What's on the headphones out?
What happens if you use the lowest "Reference Level"?

Which devices did show the problem?

both left and right are same.
Not on the headphone or IEM
The reference level is already lowest (-5dBU)
I try to connect to my Iloud MTM speakers, Stax T-8000 amp and my linn preamp.

4 Reply by MC

  • MC
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Re: Adi2 dac high pitch noise with RCA when play dsd256

Did you try a different DSD player?

Regards
Matthias Carstens
RME

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  • Registered: 2020-09-18
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Re: Adi2 dac high pitch noise with RCA when play dsd256

I try to use HQ player and still.
I don't think it relates to DSD player since the XLR output has no issue at all.

MC wrote:

Did you try a different DSD player?

  • Registered: 2020-09-18
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Re: Adi2 dac high pitch noise with RCA when play dsd256

Also, I try Roon but has the same result

MC wrote:

Did you try a different DSD player?

7 Reply by KaiS (edited by KaiS 2020-09-18 13:10:48)

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Re: Adi2 dac high pitch noise with RCA when play dsd256

Obviously the problem is somewhere in the interconnect.

Did you try different RCA cables? How long are the cables you do use?
Maybe too high capacitance makes the ADI-2 output oscillate, then, see down below...


If this doesn't help maybe a ground loop issue:
Can you try to half pull out the RCAs, so that the sleeve does not make contact any more?
Do this with the STAX (best) or the Linn connected, set to low volume.
Not with the active speakers!

This breaks the ground connection, may result in a big hum if no other ground path is present.



The high amount of ultrasonic noise DSD contains, together with the above, might have adverse effects.
Somewhere in the electronics these frequencies could be demodulated into the audio band.

KaiS's Website

  • Registered: 2020-09-18
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Re: Adi2 dac high pitch noise with RCA when play dsd256

I try different RCA cable, all with same result. Mostly I use Mogami gold rca cable bought less than a year.

When I half pull out the RCA, the issue become much worse.
The high pitch noise for dsd256 is much louder and it start happend to 44k and 96k.

I think you are right, it is related to ground issue. After plug off my DP wire to my monitor which also grounding. The noise disappear.


KaiS wrote:

Obviously the problem is somewhere in the interconnect.

Did you try different RCA cables? How long are the cables you do use?
Maybe too high capacitance makes the ADI-2 output oscillate, then, see down below...


If this doesn't help maybe a ground loop issue:
Can you try to half pull out the RCAs, so that the sleeve does not make contact any more?
Do this with the STAX (best) or the Linn connected, set to low volume.
Not with the active speakers!

This breaks the ground connection, may result in a big hum if no other ground path is present.



The high amount of ultrasonic noise DSD contains, together with the above, might have adverse effects.
Somewhere in the electronics these frequencies could be demodulated into the audio band.

9 Reply by KaiS (edited by KaiS 2020-09-19 06:18:40)

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Re: Adi2 dac high pitch noise with RCA when play dsd256

MasterBaitor wrote:

...

I think you are right, it is related to ground issue. After plug off my DP wire to my monitor which also grounding. The noise disappear.

So the ground loop has to be broken.
The best position for this is the USB connection.

There are solutions available, e.g.:
https://smile.amazon.de/iFi-iDefender-E … 5&th=1
I did not test this one, but it has good reviews and is said to work with higher samplerates too.
Needs a separate little PSU, like the one from a cell phone.


Alternatively the ADI-2 could be feed by an optical cable, if such a connection is possible with your computer.


The grounding is the achilles heel of the ADI-2 series, unfortunately digital and analog ground are not separated.
I have to admit that such a separation is not a simple task, technically, and costs a $.

KaiS's Website

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Re: Adi2 dac high pitch noise with RCA when play dsd256

Ironically, I have already added a ifi idefender to my usb connection previously.
Apparently the idefender still didn't completely isolate the usb although it did solve the coomon humming grounding issue I had before.

Maybe another solution is not connecting my monitor to ground like using a 2-pin power cord so that the only place grounded will be the output device.

Anyway, really appreciate your help for guilding me through allocating the problem.

KaiS wrote:
MasterBaitor wrote:

...

I think you are right, it is related to ground issue. After plug off my DP wire to my monitor which also grounding. The noise disappear.

So the ground loop has to be broken.
The best position for this is the USB connection.
There are solutions available for this.

Alternatively the ADI-2 could be feed by an optical cable, if such a connection is possible with your computer.


The grounding is the achilles heel of the ADI-2 series, unfortunately digital and analog ground are not separated.
I have to admit that such a separation is not a simple task, technically, and costs a $.

11 Reply by KaiS (edited by KaiS 2020-09-19 06:22:25)

  • KaiS
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Re: Adi2 dac high pitch noise with RCA when play dsd256

The ifi Defender is said to need a separate little PSU, like the one from a cell phone to do it's job removing high frequency noise.

KaiS's Website

  • Registered: 2020-09-18
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Re: Adi2 dac high pitch noise with RCA when play dsd256

I tried different cell charger.
The idefender indeed use the power from charger but the noise is there.
Maybe I should consider buying the low noise psu power made by ifi.


KaiS wrote:

The ifi Defender is said to need a separate little PSU, like the one from a cell phone to do it's job removing high frequency noise.