Filter brewing for the Soekris R2R

I have a problem playing 24/192kHz files on the dam1021. Not with all albums, but with some of them playback stutters and after a fraction of a moment continues. Could the problem be in the filter that is loaded into the DAC? What filter would you recommend for the dam1021 that would handle all sampling rates up to 24/192kHz?
 
Hello, sry if this has been asked but I don't think so: How do I get custom filters in my dac2541?

And for the lack of a better forum (and because Soeren is not answering me), please allow this question: I somehow altered the initial volume setting in my dac2541. Now when I power it up, it starts with 00db, blasting my ears when I don't pay attention. Initially it was at -40. Whatever I do, it will not save the setting and after powering down it is still 00db. What I did (from memory) was typing set volume=-30... What am I doing wrong?
 
Hi,

I made a Windows application for designing FIR Filters for the dam1021. included are various spectral windows also the Albrecht 3rd to 11th-term and some albrecht modified minimal side lobe windos. You can import filters from text file and the full list of filters can automatically be written to a mkrom readable file.

attached are some photos.
the app is in beta status so everyone who wants to try it just text me and I'll PM it.

app_1.png
app_2.png
 
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TNT

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Very nice and surely convenient!

You could introduce a "shadow line" corresponding to the fact that coefficients are only stored as 32 bit in the .skr file. So no "200 dB". This means that the filter will not in reality be as your "Magnitude Response" window show. The internal computation is using 38bit I think. The ladder is 28.

//
 
OkOk, here it is: late new years Filter Set.
I tried to make them as short as possible...

This is complete Set! all Filters are there.. even up to DSD256

Table1.png

Table2.png



No 04 & 08 - Hann (145 Coeffs) and Albrecht - Cascaded:

04_08_Hann_Albrecht.png





No. 05 & 09 - Albrecht 4-Term (339 Coeffs) and Albrecht 11-Term- Cascaded:

05_09_Albrecht_Albrecht.png




No. 06 & 10 - Kaiser (27 Coeffs) and Kaiser - Cascaded

06_10_Kaiser.png





No 07 & 09 - Mininmal Phase (229 Coeffs) & Albrecht - Cascaded:

07_11_Equi_albrecht.png






And there is news about my App !
You can now also design IIR Filters and import 1021filt.txt Dam formatted text files ;) so you can just change one filter and export the whole set with the changed filter

Again - still Beta - more testers needed ;) just send me a privat message.
 
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WOW, thanks for that! I quickly uploaded these filters, but I changed some variables in my setup (the field coil current, amplifier damping factor), so I can't make any valuable comparisons. I can only say that F5 is the only filter with "normal" volume levels, the others are too quiet. I am using V1 if it makes any difference.
 
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Hi,

I added fixed point Frequency Response Estimate to the App and a Gain setting, so you can change the Gain of a Filter and see estimated real world results. The DSD Filter Designer is now a propper Decimation Filter as opposed to the FIR1 & FIR2 Filters that are interpolation Filters.

The Fixed point calculation is on the basis of Infos I got form the main thread, so:

Input format: 2.22
Coeff format 2.30
muliplier: 35.35
ladder output: 4.24

If the gain setting is too high, you will see this immediately in the Magn. Response estimate Plot
The default Value for FIR1 = 0.7875
The default Value for FIR2 = 1
These Values come from this example:
The sum of Normalized Coeff =1
Interpolationrate e.g = 8
Gain Correction = 0.7875
_________________________________________
Multiplied = 6.3

This Gain Correction Faktor was better to implement, as this is the same for all Interpolation Rates
example for DSD:
sum(Coeff) = 1
Interp.Rate = 1
Gain Loss DSD = 6dB = 2
final Gain = 24dB = 15.85
Gain Correction = 0.7875
____________________________________
Multiplied = 24.9 which is close to Soerens 25.6

But again: Always check the Magnitude Response Estimate and adjust the Gain so it wont Overflow


Here's a link to the app on my website - yes, the file is huge..

https://jp-hoffmann.de/Files/DamFilterDesigner2_3.zip

It is ready for a broader test run. There shure will be some errors, so please do report.
Greetings
 
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I am about to order the new dam2941. I built a 1941 in the past and it's now in use in another part of the house.
The 2941 design isn't completely clear to me. The 1941 was supposed to be the oem equivalent of the dac1541, since then we have some evolution with the dac2541 and 1021 rev7. As you know there was design changes and the filters aren't the same now.
So it's not very clear if the 2941 could be considered the oem version of the 2541 with all the changes, or if this is just a rebuild 1941 with a latice fpga.
I really liked the Paul's filter pack, i was using mostly the EQHQ filter and C128dp. I want to know if i can use it with the 2941.
 
Yes, its a powerfull tool - very heavy :D

I just finished writing code to import .skr files and all of them ALL from the oldest dam1021v1 to the newest dam21xx
But just a little more time because as of now all filters are importet at once, but I want to make it seperable.

And that will be the issue here: what 'aera' is your text script from? and is it full text or coefficients only?
 
I will not display your filters.
But with the app you can upload any skr file and print the filters out as txt.
Now everyone can mix and match existing filters, and add their own creation.
Should I not go forward on updating the app? - I'm already uploading and can then swap the download location.
 
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