Hello all,

I have a question regarding the Digiface USB and headphone use. I will just ask the question first and if anyone is interested, I include all the steps I have taken to solve this up to this point.

Is the Digiface USB headphone output meant only for high impedance headphones?

I have looked at the specs, but I do not have the knowledge to understand them I must admit. I am aware that a weak amp can have trouble to drive high impedance headphones, but I could not really find information on what can happen the other way around. I also saw in the manual, that it says "Stereo Analog Line/Headphone Out", so I guess it is multi purpose.

I have the following problem: Using the Digiface USB headphone output I hear faint clicking and popping noises. I have tried to rule out the cause (please see below, if you are interested) and I believe that either there must be a problem with the combination of the headphone amp and the used headphones or it must be a faulty unit. I am otherwise quite happy with the Digiface, but I will soon be traveling and I cannot really work unless I can get rid of this issue. Since I can still return the Interface I am trying to figure out, if I should do that or if I just need to get new headphones.

When the problem occurs:

The first time I noticed this was trying to program a bass line. After each note I heard a little “pop” in my right ear. Weirdly this sound stays the same when I adjust volumes in TotalMix. So, when I turn the signal so far down that I barely hear the Bass I still hear the “pop” or “click”.
All the headphones at my disposal are low impedance headphones, so I am thinking that unless my unit is broken maybe that is the issue. I know the Babyface has two headphone outputs, and one is meant for high and one for low impedance headphones. Could anyone confirm if they had this happen before?

When it does not happen:

-    Using different audio interfaces (Zoom U44, Focusrite Saffire 6 USB)
-    Using the digital output from Digiface to the Zoom U44 I can neither hear it on headphones nor monitor speakers.

What I have already done on my Windows 10 PC and Macbook M1 without resolving it:

-    Updated Drivers
-    Updated Firmware
-    Ran Latencymon (Windows / all good)
-    Tried different USB cables
-    Reset TotalMix
-    Muted all other Inputs and middle the middle row.
-    Used different audio sources (Mainly Reaper and VLC)
-    Switched USB ports
-    Switched Rooms (Macbook)
-    Removed Power Supply (Macbook)
-    Switched Headphones (ATH-M40 X, ATH-M40fs and AKG K451)
-    Turn down the levels in TotalMix until I barely hear the sound and record it using loopback. The issue persists when using headphones with the Digiface, but the recorded sound is “normal” on other sound cards.

Any help would be appreciated!