Topic: Analog input levels at -74

Hello,

I have a new ADI-2 Pro FS black edition.  The analog input levels show as -74.0 from the moment I plug it in to power.  No other cables are attached.

If I touch my finger to either of the XLR push buttons for the analog inputs, I see the corresponding level spike to -45.0 for a second or two.

I have tried it on 3 different circuits in my home, all 3 show the same -74.0 analog input level with nothing connected but the power supply.  I have tried a different 12V power supply, and still have the same results.

The unit also seems to run very warm.  It is much warmer than my main amplifier, even if the ADI-2 is just turned on and not doing anything.

How can I go about troubleshooting this noise?  I've looked at a couple of other posts regarding what seemed like similar issues, but nothing in them addressed what I am seeing.

Thanks,
David

2

Re: Analog input levels at -74

Noise on the display's meter should not go over around 92 dB (worst case at 768 kHz and +4 dBu), and the unit should not get 'very warm' doing nothing. There seems to be something broken which causes high current / power consumption. Contact your dealer to exchange this unit.

Regards
Matthias Carstens
RME

Re: Analog input levels at -74

Thank you, doing that right now.

Re: Analog input levels at -74

Hello,

I have received the replacement unit, but I am still seeing noise on the display for the Analog Input.  Here is a breakdown of what I see in USB mode, with the following setup:
Windows 7 64-bit
madiface driver 0.9736
RME V. 102
analog input reference level set to +13db
no cables connected (except USB)

Sample rate, left channel, right channel
44100, -104, -106
88200, -100, -102
192000, -79.5, -79.1
384000, -62, -61
768000, -44.5, -45

When I disconnect the USB cable, I see:
192000, -79.7, -80.0

Is this behavior what I should expect to see?  From your earlier comments, it seems way out of expectations.  Can you help me troubleshoot this?

Thanks,
David

5

Re: Analog input levels at -74

This is expected behaviour as I explained in post 2. What's missing there is that the pre level meter shows the whole bandwidth, so -4x dB at highest sample rate is normal. To see a value that is more equalling normal bandwidth set the level meter to Dual mode (pre plus post), in the SETUP Display menu. The values seen then are at least band limited to around 40 kHz.

The manual also includes a chapter explaining that, 39.4 or so...

Regards
Matthias Carstens
RME

Re: Analog input levels at -74

dswift wrote:

Hello,

I have received the replacement unit, but I am still seeing noise on the display for the Analog Input.  Here is a breakdown of what I see in USB mode, with the following setup:
Windows 7 64-bit
madiface driver 0.9736
RME V. 102
analog input reference level set to +13db
no cables connected (except USB)

Sample rate, left channel, right channel
44100, -104, -106
88200, -100, -102
192000, -79.5, -79.1
384000, -62, -61
768000, -44.5, -45

Same situation. Adi 2 pro 1st edition. First owner from 2017.
My opinion is not a level meter mistakes. It is PCM high frequency distortions and artifacts in AD process. And best practice for ADI2Pro is not use more than 96kHz for AD.

7 (edited by KaiS 2021-10-28 19:17:36)

Re: Analog input levels at -74

You all look at the noise levels when nothing is connected, right?!
This does not make much sense IMO.

Off course, into an unterminated input a lot of stray noise can creep in.
But it’s not possible to record anything if nothing is connected, so why worry!

Once you connect an analog source you will only see the self noise of the source. You will have a hard time to find a natural source that exceeds 90 dB SNR.

8

Re: Analog input levels at -74

integra wrote:

Same situation. Adi 2 pro 1st edition. First owner from 2017.
My opinion is not a level meter mistakes. It is PCM high frequency distortions and artifacts in AD process. And best practice for ADI2Pro is not use more than 96kHz for AD.

It's neither distortion nor artefacts. It is noise shaping, as explained in chapter 34.5 already in the very first manual 1.0 of 2016. Here is the oldest version from our website:

https://www.rme-audio.de/downloads/adi2profs_e.pdf

Regards
Matthias Carstens
RME