Filter brewing for the Soekris R2R

What can I write already ...

I will write a little about sound. Recently, I like to listen to Tomasz Stańko. On the album Dark Eyes, the sound of the trumpet acquired an amazing texture. You can hear the hum very clearly, the murmur air from this instrument. This is a detail that I haven't heard before.
This is just an example. It is really very good.
 
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This filter set allow to compare 4K FIR reconstruction filters vs NOS++
F4 4K Linear phase Brickwall filter cut off frequency 21kHz
F5 4K Linear phase Brickwall filter cut off frequency 24kHz
F6 4K Linear phase Brickwall filter cut off frequency 40kHz
F7 NOS/NewNOS stack
Different filter only on 44.1/48kHz, all over are NOS.
Level matched.
Anti-aliasing/imaging IIR cascaded filters.
FIR2 filters are identical for all.
 

Attachments

  • 1021filt_Recon.zip
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For comparison with original fw1.21 reloading complete filters is needed.
In my “recon” filters set all FIR 4k filters are created by me with rePhase. It’s more about searching answers and solutions(see freq), but of course it’s possible to put any filter from txt and compare.
This is exactly what we miss, you publish skr file and not txt :( same for TNT :mad:
we cannot mix or build our own filter set mixing your works..
 
Different approach to reconstruction. This time first stage is NOS on all filters F4-F7. Tweaking is done on second stage with FIR2 filters. It’s more subtle focused on tonal balance, dimensions, musicality and overall coherency of perceived sound. All are oscillating around same target. Anti-aliasing/imaging done by IIR filters. Unfortunately all filters are ca. -12dB lower than original filters. Manual gain compensation command would be a nice feature in future firmware release.
 

Attachments

  • 1021filt_DT2.zip
    1.5 KB · Views: 86
8x1 is moving average filter which is not the best one. I was using this filter in my previous filters stack to maintain gain but I discover that even on this level of sample rate influence can be heard. F7 filters stack in my last release DT2 is NOS and 8x1 stack so every one can see is there any difference or not. So that’s why I’m asking for manual gain compensation.
 
It’s hybrid of NOS on first stage and up sampling filters on second stage, build and selected to demonstrate potential exploration area. From my perspective they sound as described from closer to distant sounding, but I’m very interested of comments.

F4 Closer sounding, more intime, warmer.
F5 For me best balanced, natural.
F6 Litle more distance but still close to be engaging.
F7 Colder more distant. is classic stack NOS/NewNOS
 
I’m listening on designed by me and quite unique planar headphones. All other equipment,cables,etc beside amplifier which is now Mjolnir 2 is also custom.
There are few things like linear phase response, extended bass, well controlled reflections, low distortion and high frequency roll-off which for sure differ my setup.

As you probably know I’m searching for answers and have a lot of doubts which I’m trying to show. I’m very interested in your opinion. All information that you give me already was very informative.