[Joe Bloggs]

Epic, @Joe Bloggs !!

There’s a lot that is super exciting here, and a lot to digest. I’m going to have to take some time off over the holidays

Here’s something I’m really excited about: we can have filters (optimized to our preferences) for specific sample rates! dCS and likely others do this (automatically of course, but I’m fine with manual).

Great call-out on the bug. Duly noted. This does not apply to NOS switch, correct? Just NOS off, and a non-default filter selected (or earphone selection).

Thank you for all your hard work here, Joe.

the way the bug worked is (after much experimenting), if you left the controller screen open and went elsewhere to pause or play music (so using the square screen button to change windows instead of exiting using the left arrow on top left), it always reverted, not to the first filter, but the filter you were using before you entered the screen.

To work around this for now, always hit the exit button (left arrow on top left) after making a change on this screen.

The NOS switch is not affected by this. But turning it on does render all the Lowpass filter choices moot (as those are all choices of what lowpass filter to use AFTER oversampling).

 

[loplop]

the way the bug worked is (after much experimenting), if you left the controller screen open and went elsewhere to pause or play music (so using the square screen button to change windows instead of exiting using the left arrow on top left), it always reverted, not to the first filter, but the filter you were using before you entered the screen.

To work around this for now, always hit the exit button (left arrow on top left) after making a change on this screen.

The NOS switch is not affected by this. But turning it on does render all the Lowpass filter choices moot (as those are all choices of what lowpass filter to use AFTER oversampling).

Ah—so if you choose a filter, exit with the top left arrow, then that filter will always stick even when the player is operated with its physical buttons, etc? The key is just not staying on/leaving Darwin open, correct?

 

[gLer]

Ah—so if you choose a filter, exit with the top left arrow, then that filter will always stick even when the player is operated with its physical buttons, etc? The key is just not staying on/leaving Darwin open, correct?

And, from what I understand, the filters are also incressingly less effective past certain sampling rates. So they'll be less effective for 48kHz files than 44.1, and all but inaudible with 96kHz files. They don't work at all beyond 96kHz. And they don't work at all with MQA. Again, this is just from what I've picked up chatting to @Joe Bloggs, so he can elaborate further if need be. Just in case you mainly listen to Hi-Res or MQA music.

 

[GiullianSN]

And, from what I understand, the filters are also incressingly less effective past certain sampling rates. So they'll be less effective for 48kHz files than 44.1, and all but inaudible with 96kHz files. They don't work at all beyond 96kHz. And they don't work at all with MQA. Again, this is just from what I've picked up chatting to @Joe Bloggs, so he can elaborate further if need be. Just in case you mainly listen to Hi-Res or MQA music.

So basically not useful for the majority of the users in this forum, right?

 

[loplop]

And, from what I understand, the filters are also incressingly less effective past certain sampling rates. So they'll be less effective for 48kHz files than 44.1, and all but inaudible with 96kHz files. They don't work at all beyond 96kHz. And they don't work at all with MQA. Again, this is just from what I've picked up chatting to @Joe Bloggs, so he can elaborate further if need be. Just in case you mainly listen to Hi-Res or MQA music.

Increasingly less audible, I think is a better way to put it. I can explain if you’d like.

Filters are not used at all at the max sample rate supported by the DAC, so that would be 352.8/384 IIRC.

Most of my music is 16/44, I haven’t counted in awhile but back in the early 2000s I had over 1000 cds. I do have a fair amount of hires and DSD, as well as about 10 years of personal recordings in 24/88.2 or 24/96 (I’m a “taper”). No MQA, although I just re-upped Tidal because the SP2000T is crap at Qobuz. And of course Qobuz has a lot of hires in the styles I mostly listen to.

So I guess I listen to a huge variety. Lol. But 16/44 is very important to me

 

[gLer]

So basically not useful for the majority of the users in this forum, right?

Not quite, but it's just worth keeping in mind. And if you're not hearing any difference, could be why.

 

[Joe Bloggs]

https://www.dropbox.com/s/n3iaz63bumeogfw/filter.zip?dl=0

Version 2 package

I noted some artifacts caused by clipping when testing with the sweep, so I reduced the filter volume by 0.5dB for my filters.

The clipping is actually more severe for some of the stock filters, so I reduced those by between 1 and 3.5dB.

e.g. full scale sweep, Darwin filter 5 (one of the worst offenders), before and after adjustment

Of course music is not a full scale sweep, but the effect may still be significant, what with the high volume a lot of music is mastered at.

 

[loplop]

https://www.dropbox.com/s/n3iaz63bumeogfw/filter.zip?dl=0

Version 2 package

I noted some artifacts caused by clipping when testing with the sweep, so I reduced the filter volume by 0.5dB for my filters.

The clipping is actually more severe for some of the stock filters, so I reduced those by between 1 and 3.5dB.

e.g. full scale sweep, Darwin filter 5, before and after adjustment

I'm not 100% sure what I'm looking at there, is that a frequency sweep and resulting aliasing artifacts? Out of curiosity, what is the X axis?

Anyway, if so, maybe that's why there's issues with spatial/low level detail retrieval with stock filters. Really looking forward to trying these, Joe.

 

[Joe Bloggs]

I'm not 100% sure what I'm looking at there, is that a frequency sweep and resulting aliasing artifacts? Out of curiosity, what is the X axis?

Anyway, if so, maybe that's why there's issues with spatial/low level detail retrieval with stock filters. Really looking forward to trying these, Joe.

Yes, and the X axis is time.

Note that as far as I can tell, all these filters are bypassed in NOS mode, and (more testing needed here) also with DSD sources (the DSD filter should apply instead)

 

[Joe Bloggs]

I'm personally digging (against all my theoretical better senses) for the moment the second last filter in this new list of mine, the non-LPed. It needs to be this much lower in volume than all the other filters to avoid distortion (seems that somehow the headroom at high ultrasonic frequencies is lower), and by the book this appears to be more a case of the hippo that can dance than a serious play, but we're basically looking at another take on the NOS philosophy: here we are oversampling but letting the supersonic artifacts completely fall exactly where they may. Result is like the NOS "filter" but without any rolloff in the passband. And as long as your earphones don't IMD the ultrasonics back down to audible frequencies, the artifacts (after tuning) are all inaudible!

 

[loplop]

Yes, and the X axis is time.

Note that as far as I can tell, all these filters are bypassed in NOS mode, and (more testing needed here) also with DSD sources (the DSD filter should apply instead)

Thank you.

They *better* be bypassed when you click NOS or DSD is playing

I like having a theoretically "perfect" (or as perfect as possible) filter in my back pocket, but I listen to mostly NOS, anyway. There are times, though, I believe due to the ADC used in the recording, that a "proper" filter sounds a lot better. Brickwalled recordings especially, in my experience. My Metrum falls apart on those.

 

[Electrocrytic]

Oooh a black RS6

 

[Joe Bloggs]

After much experimentation, I can only report that the bug with the new filter setting not sticking is unpredictable. I can report that a filter change must be made while music is playing (not when the player is paused) for the change to ever take effect; then, it can sometimes stick through pauses and restarts and sometimes not, but I haven't figured out what makes it stick. I guess we must simply wait for a bugfix upgrade.

 

[Electrocrytic]

And modded and rooted I'm tempted

 

[loplop]

After much experimentation, I can only report that the bug with the new filter setting not sticking is unpredictable. I can report that a filter change must be made while music is playing (not when the player is paused) for the change to ever take effect; then, it can sometimes stick through pauses and restarts and sometimes not, but I haven't figured out what makes it stick. I guess we must simply wait for a bugfix upgrade.

Thank you for the troubleshooting and being so open about the results, Joe.