Filter brewing for the Soekris R2R

[bbest]

This is a set of 4k filters.

• 4k-Kaiser linear phase filter that improves on the manufacturer's version.Has less ringing in the passband, attenuates more in the stopband 170 dB, and has a higher cutoff frequency. It also has better bass response and a narrower impulse response. Best fase response.
• 4K-Nyquist. Linear pase filter improves the manufacturer´s versión. Has less ringing in the passband. Attenuates more in the stopband 170 dB. Has a higher cutoff frequency plaint to 22 kHz. It also has better bass response and a narrower impulse response. The Best fase response to 22 kHz. At the sampling point, it is exactly the value of the sample. The rest of the points are interpolated by 4k. This is the one with the least theoretical distortion.
• Quasi-NOS is a very short impulse with an impulse response almost as good as NOS but with a flatter frequency response. It's very similar to the manufacturer's F7 but shows less distortion.
• NOS. It makes the DAM behave exactly like a NOS DAC.

Hello!

Does those filters will be suitable for dam2941 ?
On official download page http://www.soekris.dk/download.html , there are different filters for dam2xxx boards and others.

 

[adydula]

I have a Soekris 1421 here that a friend loaded the filters.
Want to make sure I understand what light is associated with the LED light colors.

OFF - 4k-Kaiser linear phase filter
Red - 4K-Nyquist. Linear phase filter
Orange (dim red?) - Quasi-NOS
Green - NOS

Do these associate in this order?

Thanks
Alex

 

[piorasz]

To zestaw filtrów 4k.

• Filtr liniowy 4k-Kaiser, który jest lepszy od wersji producenta. Ma mniej dzwonienia w paśmie przepustowym, bardziej tłumi w paśmie zaporowym 170 dB i ma wyższą częstotliwość odcięcia. Ma również lepszą odpowiedź basową i węższą odpowiedź impulsową. Najlepsza odpowiedź fazowa.
• 4K-Nyquist. Liniowy filtr pasowy poprawia wersję producenta. Ma mniej dzwonienia w paśmie przepustowym. Tłumi bardziej w paśmie zaporowym 170 dB. Ma wyższą częstotliwość odcięcia do 22 kHz. Ma również lepszą odpowiedź basową i węższą odpowiedź impulsową. Najlepsza odpowiedź fazowa do 22 kHz. W punkcie próbkowania jest to dokładnie wartość próbki. Pozostałe punkty są interpolowane przez 4k. To jest ten z najmniejszym zniekształceniem teoretycznym.
• Quasi-NOS to bardzo krótki impuls z odpowiedzią impulsową niemal tak dobrą jak NOS, ale z bardziej płaską odpowiedzią częstotliwościową. Jest bardzo podobny do F7 producenta, ale wykazuje mniejsze zniekształcenia.
• NOS. Sprawia, że DAM zachowuje

This is a set of 4k filters.

• 4k-Kaiser linear phase filter that improves on the manufacturer's version.Has less ringing in the passband, attenuates more in the stopband 170 dB, and has a higher cutoff frequency. It also has better bass response and a narrower impulse response. Best fase response.
• 4K-Nyquist. Linear pase filter improves the manufacturer´s versión. Has less ringing in the passband. Attenuates more in the stopband 170 dB. Has a higher cutoff frequency plaint to 22 kHz. It also has better bass response and a narrower impulse response. The Best fase response to 22 kHz. At the sampling point, it is exactly the value of the sample. The rest of the points are interpolated by 4k. This is the one with the least theoretical distortion.
• Quasi-NOS is a very short impulse with an impulse response almost as good as NOS but with a flatter frequency response. It's very similar to the manufacturer's F7 but shows less distortion.
• NOS. It makes the DAM behave exactly like a NOS DAC.

Great job. I've been listening to the F5 filter for 2 days now and I'm impressed.

 

[danny_66]

Yes, it's pre-revision 7. However, the TXT file is available if someone needs to adapt it to version 7. Or put DC filter.

Hi oneoclock,
I've created a version of your filters for rev7,
I did this by copying the new type 14 Minimum Phase FIR2 filters from the original Soekris filters to your file.
It seems to work 🙂

 

[piorasz]

I have a Soekris 1421 here that a friend loaded the filters.
Want to make sure I understand what light is associated with the LED light colors.

OFF - 4k-Kaiser linear phase filter
Red - 4K-Nyquist. Linear phase filter
Orange (dim red?) - Quasi-NOS
Green - NOS

Do these associate in this order?

Thanks
Alex

No.
F4 Kaiser - led red
F5 Nyquist led orange
F6 Quasi-NOS led green
F7 NOS led off

 

[mediumgrade]

Greetings!

I have a dam1021 Rev7 and I tried a few different filters from this thread which caused the DAC to give me no output. I was able to fix this by uploading the stock filters again, but do I understand correctly that filters have to be specifically made for Rev7 in order to work? I am looking for a good NOS filter, any recommendations for dam1021 Rev 7?

 

[danny_66]

Two posts up

 

[mediumgrade]

@danny_66 , thanks. I'll have to try those sometime.

Is there any explanation somewhere on how the filter system actually works? I see from the terminal interface that you can switch between filter modes (linear, soft, etc), but how does that correspond to the broad list of filters that show up when you run "filters all" ?

 

[SebastianL]

If you are talking about selecting one of the four filters, the syntax in uManager is:
set filter = soft
exit

Each of the four filters are named linear | mixed | minimum | soft
So in the command line above you can substitute soft with either one of the four filter names.

Alternatively you can select filters when connected to the dam1021 while not in the uManager by simply pressing the function keys F4, F5, F6 or F7 (I believe?)

 

[mediumgrade]

@SebastianL , thank you. I understand the syntax of changing between filter modes, but what I don't understand is how those modes correspond to the list of filters that are displayed when I run the "filters all" command.

 

[SebastianL]

As I see it every filter needs to have a setting for each possible sampling frequency. 44.1Khz, 48Khz etc.
But I’m no expert in this.

 

[mediumgrade]

@SebastianL , oh, that makes total sense. So, for each filter mode, we need to represent every possible combination of bit depth and sample rate. And, the filters that I upload will determine the characteristics of each mode.

 

[living sounds]

"filters=all" displays a list, it doesn't change any settings.

 

[SebastianL]

Hi oneoclock,
I've created a version of your filters for rev7,
I did this by copying the new type 14 Minimum Phase FIR2 filters from the original Soekris filters to your file.
It seems to work 🙂

Does this mean that we can upgrade any of this threads diy filters to a rev7 version?

 

[vdi_nenna]

What is the lastest recommeneded filter set? Think I last used Paul's Party-pack and oneoclock's 106 flters. Dont remember if the pasrty-pack can ran DSD. It's been a few years since I made changes. Thanks.

 

[secanbj]

I would try oneoclocks filter , i like them alot

Post in thread 'Filter brewing for the Soekris R2R'

2024-08-13 1:56 pm

This is a set of 4k filters.

• 4k-Kaiser linear phase filter that improves on the manufacturer's version.Has less ringing in the passband, attenuates more in the stopband 170 dB, and has a higher cutoff frequency. It also has better bass response and a narrower impulse response. Best fase response.
• 4K-Nyquist. Linear pase filter improves the manufacturer´s versión. Has less ringing in the passband. Attenuates more in the stopband 170 dB. Has a higher cutoff frequency plaint to 22 kHz. It also has better bass response and a narrower impulse response. The Best fase response to 22...

• oneoclock

• 

 

[franckc2]

Seconding @bbest question above can the oneoclock filters be used with a DAM2941 ? if yes should it be the version prepared for dam1021v7 made available by @danny_66 or the standard one that @oneoclock provided ?