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[mrboonmee]

what is Safe Low-pass filter?

also, "not using enough bits to output the input directly"?

DAC is iFi Gryphon using USB from PC. iFi ASIO driver

[dtc]

You are converting DSD to PCM. When you do that, there is a lot of high frequency noise generated.  That noise needs to filtered out to protect your equipment. There are various options to do that. The Safe Low Pass filter is the default. It is a low pass filter at 24KHz with a slope of 48dB/octave.  There are other options that start at a higher frequency and with different slopes.   The original Sony filter was 50 KHz with a slope of 48 dB/octave.  You set the filter option in Tools - Options - Audio - Advanced - Input Plug-In - DSD. You probably will not hear the difference.

[mrboonmee]

I didn't realize DSD had to be converted to PCM, interesting. and the DAC says DXD. 

and "not using enough bits to output the input directly"?

Thanks again

[Awesome Donkey]

Try enabling DSD bitstreaming if you want to avoid the DSD to PCM conversion (which is a lossy conversion).

[dtc]

DSD does not have to be converted to PCM if your DAC accepts DSD. I think it does.  If it does, you need to turn on bit streaming for DSD files in the Audio options to pass it as DSD and not have it converted to DSD.

DXD is just a term for 352 KHz PCM. MC converts DSD 64 (2.8MHz) to 352 KHz PCM if you are not bitstreaming.

EDIT - AD beat me by 42 seconds

[mrboonmee]

Genius!

where is my safe filter? lol

[Awesome Donkey]

You don't need a lowpass filter when bitstreaming DSD, only when doing a DSD to PCM conversion. Also since you're bitstreaming DSD, any DSP in general isn't possible while doing so.

[dtc]

All playback of DSD requires a low pass format in some form. Most DACs use a process that converts DSD to multi-bit PCM. The DAC has an internal low pass filter to filter out the quantization noise.  Some DACs do not convert to multi-bit but those use a low pass filter directly, in a somewhat different form.

If you do DSD to PCM conversion in software, you need to use a low pass filter, much like the DAC does.

So, playing DSD requires a low pass filter. It just depends on where that filter is, in software or hardware, and what type of filter is used.  In the case of bitstreaming, you are sending the DSD directly to the DAC, and the DAC does the necessary filtering.