Topic: DC (Direct Current) Filter somewhere available?

hi, i own a fireface UXC II now and am amazed by the quality, also in terms of DA conversion. i note a detail:
in the spectrometer, if i include the option 'show DC in 20hz band', i can see a significant amount of direct current (0hz) arriving at the ouput.

is there any way to filter this out?

2 (edited by unpluggged Yesterday 11:34:21)

Re: DC (Direct Current) Filter somewhere available?

christian s. wrote:

hi, i own a fireface UXC II now and am amazed by the quality, also in terms of DA conversion. i note a detail:
in the spectrometer, if i include the option 'show DC in 20hz band', i can see a significant amount of direct current (0hz) arriving at the ouput.

is there any way to filter this out?

You can apply a low-cut filter at the output, but I'd also try to find out why the DC component is in the signal in the first place.

Also, what is your signal chain after the UCX II? Probably, your downstream equipment takes care of DC filtering by its own means.

Fireface UCX II + ARC USB > ADI-2 Pro FS R BE > Neumann KH 750 DSP + MA 1 > KH 120 A

Re: DC (Direct Current) Filter somewhere available?

thanks .. yes i am doing this, i apply a low cut filter with 18db/oct at 20hz. it seems to me that the cutoff is not 'complete', but at 0Hz (DC) it should actually be ..

when i have a look using digicheck ng, after applying the filter, the 20Hz band shows significantly lower level, but the delta when turning on the 'show DC' option is still visible, even though smaller.

4

Re: DC (Direct Current) Filter somewhere available?

You most probably not only see DC but still some infrasound junk of a few Hz. The filters (bands) natiurally have limited separation to the next band.

Regards
Matthias Carstens
RME

5 (edited by christian s. Yesterday 16:56:12)

Re: DC (Direct Current) Filter somewhere available?

thanks matthias.

so if i switch on the 'include DC into the 20hz band' filter option, this basically means some junk infrasound is added to this band by that function as well, so why is it named 'include DC in the 20hz band'? it should be named 'include all frequencies below 20hz into the 20hz band' or i am wrong?

it sounds to me like some dc offset removal function may be needed in addition, just in case one wants to eliminate sending this. not sure if this is relevant at all, but i just stumbled across it .. or also, adding a 10Hz, a +0-10Hz and a 'DC band / 0Hz only band' in addition, for clarity's sake.

the fireface ucx II unleashes a healthy obsession with how good the music can actually sound, thanks a lot for making this possible.

Re: DC (Direct Current) Filter somewhere available?

christian s. wrote:

thanks matthias.

so if i switch on the 'include DC into the 20hz band' filter option, this basically means some junk infrasound is added to this band by that function as well, so why is it named 'include DC in the 20hz band'? it should be named 'include all frequencies below 20hz into the 20hz band' or i am wrong?

it sounds to me like some dc offset removal function may be needed in addition, just in case one wants to eliminate sending this. not sure if this is relevant at all, but i just stumbled across it .. or also, adding a 10Hz, a +0-10Hz and a 'DC band / 0Hz only band' in addition, for clarity's sake.

the fireface ucx II unleashes a healthy obsession with how good the music can actually sound, thanks a lot for making this possible.

You still didn't tell us what is connected to your UCX II's outputs, that is, what is the equipment that you want to protect from DC?

Fireface UCX II + ARC USB > ADI-2 Pro FS R BE > Neumann KH 750 DSP + MA 1 > KH 120 A

Re: DC (Direct Current) Filter somewhere available?

And the question is, if it is DC or just subhamonic signals. And if it is really DC, how big it is comparing to the rest of signal. And also, proper audio signal should be symetrical with no DC part.....

FF UCX II, Digiface USB, Babyface Pro FS