1 (edited by mika91 2020-03-03 18:20:17)

Topic: New owner: need recommendations

Hi,

I'll receive my ADI-2 DAC tomorrow, and I have a few questions:

  • better use USB or toslink ? I remenber having some troubles with USB on my first DAC (when moving the computer mouse, I could hear high pitch noise on the speakers)

  • better use volumio on Odroid C1 (via USB) or Raspberry pi 2 (via Digi+ optical or coax)

  • any recommendation on good and cheap <500€ amplifier (ncore nc252 ? naim nap100 ? ...)

  • there is no trigger out on the DAC. How do you power on the amplifier ?

  • any recommendation on good tutorials or videos to learn how to measure the room correction filters ?

  • any recommendation to base EQ bands settings, to play/tweak with ?

Thanks

2 (edited by ramses 2020-03-03 18:28:11)

Re: New owner: need recommendations

There is no difference between the different digital inputs.
And you can validate it on your own by using the bit perfect test files.

> How do you power on the amplifier ?
Usually by turning it on or what do you mean ?

> any recommendation to base EQ bands settings, to play/tweak with ?
It should be clear that there are no general settings to make sound better or to correct a room.
Or what do you mean ?

BR
Ramses
X10SRi-F, Win10 Pro 1909, Cubase, UFX+, Octamic XTC, ADI-2 Pro FS BE/R BE, RayDAT, ARC USB

Re: New owner: need recommendations

ramses wrote:

> How do you power on the amplifier ?
Usually by turning it on or what do you mean ?

Some devices have RCA or TS 12V trigger to power on devices that are attached to them wink

ADI-2 DAC (with stock PSU) - Neumann KH 310 A monitors - Cheap USB and XLR cables

Re: New owner: need recommendations

oh careful, high tech ;-)

Unbelieveable .. I am more traditional, I would expect a power knob wink

BR
Ramses
X10SRi-F, Win10 Pro 1909, Cubase, UFX+, Octamic XTC, ADI-2 Pro FS BE/R BE, RayDAT, ARC USB

5 (edited by Curt962 2020-03-03 19:03:39)

Re: New owner: need recommendations

Hi Mike!

For testing your Speakers, and Room, this an Excellent, Step by Step Tutorial Video on how to utilize Room Eq Wizard (REW)...a FREE (Donation-ware actually) tool

Video produced by GIK Acoustics. 

https://m.youtube.com/watch?v=e4uSR3cUUSY

REW is a Very powerful tool!  With it, a Calibrated Microphone, and a bit of guidance, you can probe quite deeply into what is REALLY going on in your Set Up.

Arbitrary, General Purpose EQ settings are of no use.   

Amplifier Power?  I always found the Amp's On/Off Switch to be most effective.

Best Mate!

Curt

Vintage 2018 ADI-2 DAC. "Classic Edition"
Cables:  Red Ones, and White Ones.
Speakers:  Yes (2)

Re: New owner: need recommendations

ramses wrote:

There is no difference between the different digital inputs.
And you can validate it on your own by using the bit perfect test files.

There are a few posts about ground loops in the forum.
So maybe the digital transport is the same, but if one input is ground loop free and the other isn't (no galvanic isolation, ...) I'll go with the first one wink

And max sample rate is higher on USB than SPDIF, right ?

ramses wrote:

> How do you power on the amplifier ?
Usually by turning it on or what do you mean ?

A lot of power amplifiers can only be switch on/off using a trigger input (no power button or IR receiver).
My RME ADI-2 DAC will be used by my whole family (wife + children) in the living room, using a logitech harmony remote.
So I need to find a way to switch the power amp on using the remote.

ramses wrote:

> any recommendation to base EQ bands settings, to play/tweak with ?
It should be clear that there are no general settings to make sound better or to correct a room.
Or what do you mean ?

It's my first time with EQ, so band type, gain, q factor...are intimidating wink
I'd like to learn how  to set it up.

Re: New owner: need recommendations

Curt962 wrote:

For testing your Speakers, and Room, this an Excellent, Step by Step Tutorial Video on how to utilize Room Eq Wizard (REW)...a FREE (Donation-ware actually) tool

Video produced by GIK Acoustics. 

https://m.youtube.com/watch?v=e4uSR3cUUSY

REW is a Very powerful tool!  With it, a Calibrated Microphone, and a bit of guidance, you can probe quite deeply into what is REALLY going on in your Set Up.

thanks, I'll take a look as soon as I can.

Curt962 wrote:

Arbitrary, General Purpose EQ settings are of no use.

the idea was to quickly compare some generic EQ profiles (such as rock, jazz, electro, lyrics...) to better understand how the bands make the music sounds different, and help me to find my EQ. (which frequency I need to change, Q factor, ...)

Curt962 wrote:

Amplifier Power?  I always found the Amp's On/Off Switch to be most effective.

My kids don't agree... Harmony remote (or google assistant) is the way to go ^^

8 (edited by ramses 2020-03-03 20:05:59)

Re: New owner: need recommendations

mika91 wrote:

There are a few posts about ground loops in the forum. So maybe the digital transport is the same, but if one input is ground loop free and the other isn't (no galvanic isolation, ...) I'll go with the first one wink

If you know all that, why do you ask ?
Its simple like that, if you can use SPDIF connection, use optical SPDIF.

But if you need an USB connection, well then use USB.
In the majority of all cases there is no issue with hum or whatever noise.
Don't try to fix issues that do not exist, saves time and money.

mika91 wrote:

And max sample rate is higher on USB than SPDIF, right ?

Only relevant for DSD content. Keep in mind that many hi res audio files are only upsampled.
Upsampling doesn't bring any quality increase.
Only spoils disk space and CPU power.
And most people cant even hear the difference between a mp3 and a lossless FLAC file @44.1 kHz.

Not sure from where you come and what you worry about.
Sounds you want to make everything 250% but seem to overshoot due to lack of experience.

I would change the strategy to 1st of all enjoy your new device.
Learn how to operate it, what options it gives to you.

BR
Ramses
X10SRi-F, Win10 Pro 1909, Cubase, UFX+, Octamic XTC, ADI-2 Pro FS BE/R BE, RayDAT, ARC USB

9 (edited by ramses 2020-03-03 20:11:57)

Re: New owner: need recommendations

mika91 wrote:

the idea was to quickly compare some generic EQ profiles (such as rock, jazz, electro, lyrics...) to better understand how the bands make the music sounds different, and help me to find my EQ. (which frequency I need to change, Q factor, ...)

This has been done already by the sound engineers that produced the album so that it sounds perfect
for the artist and according his taste and experience and this is a room where the acoustic has been optimized.

If you get now an EQ in your DAC then you can use it to correct deficites of
- your room acoustic or
- your equipment or
- your ears or
to tweak it a little bit to match your personal taste. Not more. You do not use EQ for music styles...

As I mentioned room treatment, 1st objective is to find an optimum position for your speakers.
Next step is room optimization. This will keep you busy for a while.
If there is any rest, this you can try to fix with the EQ, but carefully.
See the thread of Curt..

BR
Ramses
X10SRi-F, Win10 Pro 1909, Cubase, UFX+, Octamic XTC, ADI-2 Pro FS BE/R BE, RayDAT, ARC USB

Re: New owner: need recommendations

If you know all that, why do you ask ?
Its simple like that, if you can use SPDIF connection, use optical SPDIF.

But if you need an USB connection, well then use USB.
In the majority of all cases there is no issue with hum or whatever noise.
Don't try to fix issues that do not exist, saves time and money.

The optical input will be used for TV.
Concerning the volumio device, I just wanted to know if it was better to use USB or spdif coax (via hifiberry hat board)... in other words, does the RME dac has some sort of galvanic isolation (or whatever the technical word is) on USB and coax input?


Only relevant for DSD content. Keep in mind that many hi res audio files are only upsampled.
Upsampling doesn't bring any quality increase.
Only spoils disk space and CPU power.
And most people cant even hear the difference between a mp3 and a lossless FLAC file @44.1 kHz.

Agreed. My sources are mainly CD rips and Spotify, so 44.1kHz is enough for me ^^

I would change the strategy to 1st of all enjoy your new device.
Learn how to operate it, what options it gives to you.

Yes, I think you're 100% right.

11 (edited by ramses 2020-03-03 22:27:19)

Re: New owner: need recommendations

Did you think about the possibility to use a 4:1 TOSLINK switcher in front of the ADI-2 DAC optical port ?
Then you have 4x the possibility to connect optical sources, be it ADAT or optical SPDIF. See my blog: https://www.tonstudio-forum.de/blog/ind … her-EN-DE/

The best looking TOSLINK switcher is from Oehlbach but supports only 96 kHz even if they claim 192 kHz on the package / on webpage. https://www.amazon.de/Oehlbach-Optosel- … B00NLA4G8S
It has a remote of its own. A good unit, but only capable of 96 kHz, see here my blog: https://www.tonstudio-forum.de/blog/ind … lerangabe/

> does the RME dac has some sort of galvanic isolation (or whatever the technical word is) on USB and coax input?

No this is not supported by such devices. For USB separate solutions exist, but not every solution works satisfactory.
Search forum, MC made some comments on different solutions in other threads.

Coax input is not optical ... so there is no galvanic isolation.

BR
Ramses
X10SRi-F, Win10 Pro 1909, Cubase, UFX+, Octamic XTC, ADI-2 Pro FS BE/R BE, RayDAT, ARC USB

12 (edited by KaiS 2020-03-03 22:16:43)

Re: New owner: need recommendations

mika91 wrote:

The optical input will be used for TV.
Concerning the volumio device, I just wanted to know if it was better to use USB or spdif coax (via hifiberry hat board)... in other words, does the RME dac has some sort of galvanic isolation (or whatever the technical word is) on USB and Coax

No, neither, unfortunately.


I just ran into the same problem and decided to use an 8x8 SPDIF matrix switcher (I already had), and connect ADI-2 Pro via optical to my main system.
4x2 optical matrix switchers are available for $30.

Coax caused earth loop problems here, partly because the ADI is simultanously connected to my "headphones"-system via analog;
Partly because the leakage current from ADI's PSU is exceptional high.


It was a bit unexpected that a device that claims to be "...Pro" in it's name took the shortcut to omit galvanic isolation, sparing 2 transformers that do cost $0.50 a piece if bougt in small quantities.

ADI's AES i/o has galvanic isolation, but the common workaround feeding SPDIF coax into AES didn't work(-around), as ADI's AES In is too insensitive.


In the technical standard, galvanic isolation for SPDIF coax is an option, not mandatory, but:
this, IMO, wrong decision causes a lot of headscraping for a lot of people I think.


USB is another story -
the only way to do galvanic isolation here takes a lot of effort by using a separated, individually power supplied circuit with internal optical (or even transformer coupled?) interlink.
Else, with more simplistic approaches, you easily fry the USB chip.


A remark:
In all configurations that caused earth loop related hum in other devices in my system, ADI's own headphone outs always stayed clean.

Re: New owner: need recommendations

Hi Again Mike!

You're getting off to a bumpy start.  Your new ADI-2DAC arrives soon!  Be excited!

Several have already suggested that you familiarize yourself with the device first, and foremost.   I can think of no BETTER advice!   Download the User Manual, and Dig In!   Your new RME is not a "On/Off/Vol" only affair.  Rather it is powerful, sophisticated device that Shines Brightest in Qualified Hands.  Your User Manual is the Answer.  smile

Let's simply hit "Rewind", and take it again from to Top.  One step at a time.   

Enjoy your new ADI-2DAC!

Curt

Vintage 2018 ADI-2 DAC. "Classic Edition"
Cables:  Red Ones, and White Ones.
Speakers:  Yes (2)

14

Re: New owner: need recommendations

KaiS wrote:

Coax caused earth loop problems here, partly because the ADI is simultanously connected to my "headphones"-system via analog; Partly because the leakage current from ADI's PSU is exceptional high..

That is easy to fix by connecting ground/earth at the right point. Also the leakage current is on a normal level, not higher than others. Unless you use very expensive medical power supplies.

KaiS wrote:

It was a bit unexpected that a device that claims to be "...Pro" in it's name took the shortcut to omit galvanic isolation, sparing 2 transformers that do cost $0.50 a piece if bougt in small quantities..

Unfortunately the world is more complicated. Yes, some of our older units had transformer-isolated SPDIF I/Os, heck even word clock transformer-coupled. But these days are long gone.

KaiS wrote:

In the technical standard, galvanic isolation for SPDIF coax is an option, not mandatory.

That is theory. Reality is different. These days you will have problems to pass any EMI/CE/FCC whatever certification by spitting out several MHz over a non-shielded wire. That's why you won't see galvanically isolated, unbalanced coaxial SPDIF anywhere. And even if they have tranformers (very common at the output) these are still connected to ground and serve only as high-freuency filter.

Regards
Matthias Carstens
RME

15 (edited by KaiS 2020-03-04 22:07:36)

Re: New owner: need recommendations

MC wrote:
KaiS wrote:

Coax caused earth loop problems here, partly because the ADI is simultanously connected to my "headphones"-system via analog; Partly because the leakage current from ADI's PSU is exceptional high..

That is easy to fix by connecting ground/earth at the right point. Also the leakage current is on a normal level, not higher than others. Unless you use very expensive medical power supplies.

I have to admit, the PSU's leakage (1.7uA) isn't exceptionally for a standard switch mode PSU.
My iPad's 12W PSU e.g. has 33uA, that's 20 times higher.
So as soon as I connect an USB, ADI PSU's leakage becomes completely  insignificant.


Fixing ground loop problems in an unbalanced environment is another story:
Using random ground connections doesn't solve the problem, just shifts it around.

I've de-hummed several complete studios.
The only way is (besides extremly expensive balancing every audio connection), ground isolating everything except the power amps.
Even mechanical interconnects like rackmounts need to be removed, to break ground loops.


In such a process ground loops caused by non-isolated digital connections are a special, unwelcome challenge.
My usual solution is a ground isolated digital switching matrix, serving it's original purpose as sideeffect.
These don't come cheap.


BTW, WARNING: For continued electrical safety an Fi-Circuit Breaker needs to be installed in the mains supply if any device's safety ground connection is isolated.


MC wrote:
KaiS wrote:

In the technical standard, galvanic isolation for SPDIF coax is an option, not mandatory.

That is theory. Reality is different. These days you will have problems to pass any EMI/CE/FCC whatever certification by spitting out several MHz over a non-shielded wire. That's why you won't see galvanically isolated, unbalanced coaxial SPDIF anywhere. And even if they have tranformers (very common at the output) these are still connected to ground and serve only as high-freuency filter.

I see floating transformer balancing on current Gigabit computer network interconnects, using two magnitudes higher frequencies on TP cables with ungrounded shields (at 1GHz a shield-ground would't change radiation anyway).
These transformers are built a bit different, do contain several LC filters.
Still very unexpensive and worth to take a look at.
Some of those transformers can be used as SPDIF isolators too.

16

Re: New owner: need recommendations

I don't see how this is relevant: network uses twisted pair and needs to use twisted pair. Even the data format/transmission coding is designed to use these cables and minimize EMI. This is not transferrable to SPDIF at all.

SPDIF coaxial means the shield is a signal transferring wire and therefore needs to be hard grounded, otherwise the whole cable will work as high-frequency transmitting antenna.

Regards
Matthias Carstens
RME

Re: New owner: need recommendations

My point was, a shield of a coax cable does not work as such in the classical NF way, as soon as the 1/4 wavelength of the used frequencies become shorter than the cable itself.

If the shield carries HF current, it works like an antenna in this case, no matter if grounded or not at the ends.


I have to admit, for lower sample rates and short cables this relationship is not true.

But at 192kHz SR (bitrate 12,2Mbit/s, bandwidth 25MHz?) the cable starts to radiate at 1/4 waveleght = 3m.
If grounded on both sides the backflow of the center conductor's HF current is spread all across every, even audio, connection, doesn't this make the situation worse?


I know this is theory, and I don't know under what circumstances FCC and other conformity tests are conducted.

The idea was, what's possible at frequencies a hundred times higher (Gigabit network) might even be possible here: galvanic isolation to avoid ground loops.
Specially as we had transformer balanced SPDIF in former times with already strong FCC rules.


I wouldn't beat this dead horse (existing ADI's cannot be changed anyway) so much if it wouldn't have so much influence on the usability of the ADI-2, even forcing myself to take uncomfortable measures around it.
This is meant as food for thought for later generations of RME products.


BTW: older computer networks used coax cable's up to 10Mbit with galvanic isolation too, across distances up to 60 meters.
What about their FCC conformity?

Re: New owner: need recommendations

waouh, too much technical for me here ^^

So to summarize: use optical to be ground-loop free.
For coax, it could be very complex: not sure my raspberry audio card with 'galvanic isolation' will be enough...need to test

By the way I'll receive my RME today... but didn't find any amplifier to work with yet :'(

Re: New owner: need recommendations

mika91 wrote:

So to summarize: use optical to be ground-loop free.

Yes, that's what I do in my studio as far as possible, with good success.

But I got lots of connections via SPDIF and AES too.
If galvanicaly isolated (BTW: this means no DC connection) these don't cause any problems.

Eg. I use two RME ADI-8 DD, 4xAES i/o each, connected to a bunch of AD/DA converters and never had any problems here.

mika91 wrote:

For coax, it could be very complex: not sure my raspberry audio card with 'galvanic isolation' will be enough...

No, not too much so.

Simple one side galvanic isolation is enough to break a ground loop that is causing hum.

It can easily be checked by using even the cheapest $5 Ohm meter:
no DC conductivity SPDIF to Audio connectors = no ground loop on this path.