Topic: Low Input level on USB

I switched yesterday from the 'ADI2 DAC' fs to the 'ADI2 PRO fs BE'. I switched because I want to use the analog inputs for my turntable. That is function brilliantly, the sound is great.
I did a firmware update from 112 to 116.

I notice a strange difference between the two with my USB input. I have an Innuos MK3 mini attached through USB to the RME.
In the default factory setting of the RME DAC the input was high, mostly close to 0db. I had to switch the volume back to -30 to have a comfortable listening level.
On the ADI 2 PRO however the input level seems pretty low, around between -40, -45 db. The analyser is hardly showing anything.

I tried allready a few things. Like switching Ref Level (which is on +19) off and going to +24. But this doesn't seem to influence the input signal.
I also fiddled with different Horizontal Meter settings and put it on Dual.

The input of my phono preamp looks good working in preamp mode, and the analyzer is working accordingly fine.

My question:
Why is the input level of the USB showing so low compared to the ADI2 DAC?

ps: I don't complain about the quality of the sound. To my ears it is pretty much the same as the ADI2DAC. Even with this low input level I have enough power to a comfortable listening level.

2 (edited by KaiS 2022-07-19 11:07:29)

Re: Low Input level on USB

If the USB input level is low (the thin outer Dual Meters, or the Pre-FX Meters showing low) the Innous is sending low.
Have a look there for possible volume settings.

ADI-2 does not have any means for lowering USB INPUT level built in, it cannot be the cause.

ADI-2 Pro‘s analog inputs seem to work nicely for you ?!

Re: Low Input level on USB

Hello KaiS,
The settings in the brought me to an idea.
I feel a total amateur: smile
The volume setting of the Innuos was on 26, instead of the full 100!!! Haven't a clue why this setting was changed, but surely it was me doing it!
And.. ooh yes... i see the analyzer going very well bouncing up and down... levels are great now.

I humbly apologize for this stupid mistake. Thank you very very much!

And yes the analog input work for my very well.

4 (edited by Curt962 2022-07-20 02:03:52)

Re: Low Input level on USB


Use the RME Bit Test Utility now to verify that your set-up is indeed Bit Perfect!

This test, in order to be successful, will require that your Source is at 100%, etc, et al

The Bit Test helps you to ensure that your DAC is receiving an EXACT copy of the data on your HD.

It's So easy, and such a wonderful tool!


Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes

5 (edited by KaiS 2022-07-20 07:46:29)

Re: Low Input level on USB

Curt962 wrote:

The Bit Test helps you to ensure that your DAC is receiving an EXACT copy of the data on your HD.

The Bit Test files can be downloaded here:

(From the manual page 94 (-Pro) or 67 (-DAC), where you can find an explanation of the test too)

Just play the files, ADI-2 say’s “Bit Test passed’ if everything is OK.
Else it says nothing.

For whatever reason the files are not linked in ADI-2’s download section on the RME website, and a typical search does not yield a senseful result.

Re: Low Input level on USB

Thanks Curt and Kaïs,
I found the files a while ago when I still had the ADI2 DAC fs. I did the test now and they all pass without problems.
A great tool indeed to be sure all is well.