Filter brewing for the Soekris R2R

[Dimdim]

You're right about the RPi. Max mainstream I2S SR is 192KHz.

I'm afraid that I haven't gotten around to trying the latest DAM firmware yet. It's on a looong to-do list.

 

[Ixion77]

Does the NOS filter from 2015 work with the current (v1.2) firmware on the dac1541? Is there any newer NOS filter available?
Is there a documentation about how to upload a filter to a specific slot?

 

[bmxmen]

Hello what filter is best for now? i have an 1.19 b3ta pack with 4k tap filter from soekris site. It is Good?

 

[TNT]

Wanting to do a little filter work on my 1121 I found:

1021filt_099.txt: dam1021,44100,8,4,1975,7.8
1021filt_105.txt: dam1021,44100,8,1,383,8

Sören, why did you lower the amount of used taps in a later version of your provided filters?

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[ynmichael]

Any more updates to the filters given the updates in 1.19? Or has Soren incorporated results in this thread into the stock filters?...

 

[analog_sa]

Or has Soren incorporated results in this thread into the stock filters?...

Some of the filters published in this thread and at Moredamfilters sound much better to me than the stock filters. They are also incompatible with 1.19. If you want to obtain the best the 1021 is capable of be ready to do a lot of hardware mods and try out a lot of filters.

 

[bambadoo]

Or read, research, make and test your own filters It is doable...

 

[analog_sa]

It is doable...

You have proven this, your filters rock

 

[ynmichael]

Some of the filters published in this thread and at Moredamfilters sound much better to me than the stock filters. They are also incompatible with 1.19. If you want to obtain the best the 1021 is capable of be ready to do a lot of hardware mods and try out a lot of filters.

Is the partypak 0.99 still the best theoretically? I'll have time to experiment subjectively with the filters in the future but if possible I would greatly prefer to start with a set that's accepted as technically superior. Thanks so much!

 

[analog_sa]

accepted as technically superior

No idea what the above means with respect to filters. As my priorities are different please ignore my earlier comments.

 

[TNT]

As I recall it there where different approaches in the partypack. Technically superior would be what Nyquist and the sampling theorem demand. That would be a phase linear, infinite sharp filter at Fs. Phase linear can be reasonably achieved, steepness is about available taps. I would rather trade some passband BW for absence of aliasing spurae.

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[analog_sa]

That would be a phase linear, infinite sharp filter at Fs.
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But what about pulse response?

 

[TNT]

But what about pulse response?

Theoretically correct for a band limited system. Some symmetrical pre and post "ringing", as people would call it. The "ringing" *should* be there.

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[TNT]

As I recall it there where different approaches in the partypack. Technically superior would be what Nyquist and the sampling theorem demand. That would be a phase linear, infinite sharp filter at Fs. Phase linear can be reasonably achieved, steepness is about available taps. I would rather trade some passband BW for absence of aliasing spurae.

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Eehhh Fs/2 !

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[ynmichael]

As I recall it there where different approaches in the partypack. Technically superior would be what Nyquist and the sampling theorem demand. That would be a phase linear, infinite sharp filter at Fs. Phase linear can be reasonably achieved, steepness is about available taps. I would rather trade some passband BW for absence of aliasing spurae.

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Is there a 4K tap version for the PartyPak 0.99?... Also is the wayback machine the only way to access moredamfilters now? Thanks!

 

[TNT]

That activity stoped before the last FW upgrade som I'm afraid not. Moredamfilters is closed so yes.

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[piorasz]

Hi.
Could someone share a party pack? I can not find anywhere. I will be grateful.

 

[ynmichael]

Hi.
Could someone share a party pack? I can not find anywhere. I will be grateful.

Try the wayback machine. Moredamfilters.info/filters I think is the URL. But here it is in case it's useful.

 

[ynmichael]

That activity stoped before the last FW upgrade som I'm afraid not. Moredamfilters is closed so yes.

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Would it be difficult to learn how to port the old versions to the new tap configs? Where should I start? I think it would be very beneficial to compile a collection of our best and maybe try to adapt them for the latest firmware.

 

[TNT]

The author had a lot of knowledge about filters and signal processing and did not reveal all details on how they where made so I think it would be hard/impossible. Something in 2k can never be identical/ported to 4k.

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