Filter brewing for the Soekris R2R

TNT

Member
Joined 2003
Paid Member
I don't get how seemingly one filter can serve 2 different Fs? How does this work?

Eg:

dam1021,44100,8,1005,1919,7.999999995
05 EQHQ_lpbr_b4, 44.1 Khz, 0-20.45Khz +-0.00000005dB, 22.50Khz -174dB

dam1021,48000,8,5,1919,7.999999995
05 EQHQ_lpbr_b4, 48 Khz, 0-22.26Khz +-0.00000005dB, 24.49Khz -174dB

0.0000000009197494076640424
0.0000000008983651544284088
0.0000000002186044232553024
....

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Unsure but there must probably be some wriggle room for it to work, but it's surely not optimal.

I also managed to get close to the soundstage size your filter has by sending pcm upsampled to dsd256 through Hqplayer, this way i get the best bass rumble/slam, while keeping soundstage large.
 
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I got another one of these cheap blue usb ttl - serial interfaces using the PL2303TA chip and cannot get it to work with the DAM1021... Unlike the other one I bought it works right away in Windows 10. What is the correct way to connect it? I tried both the serial and ttl connections (the latter using the isolated grounds). The interface also has a +5V cable (which I left not connected). Any help is appreciated!
 
I got another one of these cheap blue usb ttl - serial interfaces using the PL2303TA chip and cannot get it to work with the DAM1021... Unlike the other one I bought it works right away in Windows 10. What is the correct way to connect it? I tried both the serial and ttl connections (the latter using the isolated grounds). The interface also has a +5V cable (which I left not connected). Any help is appreciated!
You sure its not a silabs cp210x chip?
 

TNT

Member
Joined 2003
Paid Member
I have to admit that there is a bit of an imperfection with the TNT1 filter. I did a new one and have listened to it during the day. Definitely more clean - actually the cleanest filter I have heard on DAM. Its geared even more to the theorem and mirror suppression (-163 dB at 22,04 Khz) rather than hammering out the last 0,1 dB at 22,045 Khz... being down 0,3 dB at 19,4 - bats may weep ;-/

Please try it - no DC blocker - be warned ;) (or happy)

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I have to admit that there is a bit of an imperfection with the TNT1 filter. I did a new one and have listened to it during the day. Definitely more clean - actually the cleanest filter I have heard on DAM. Its geared even more to the theorem and mirror suppression (-163 dB at 22,04 Khz) rather than hammering out the last 0,1 dB at 22,045 Khz... being down 0,3 dB at 19,4 - bats may weep ;-/

Please try it - no DC blocker - be warned ;) (or happy)

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Wow! I was just writing down that your previous filter had much improved dynamics and clarity, but was unfortunately hard to listen to because of a harsh top end.

Now I think you nailed it. With this filter and the added capacitance the DAM1021 reminds me more of my studio tape recorder than of any digital source.

Top end rolloff should not be a concern. My Prism AD-2 starts filtering out steeply at 19.5 khz (at 44,1k samplerate). Aliasing is a bigger concern.

So, thank you, Sir!

Only one question: Output with your filters appear to be lower in amplitude than the stock filters. Why is that, and could you change it without detrimental effects?
 

TNT

Member
Joined 2003
Paid Member
Theoretical characteristics. Red is valid due to no_of_taps limitation (2k). Thanks rePhase!!!

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Forgive the dumb question, but when you guys are commenting on or explaining about various filters on the DAM very rarely do you say F7 or mixed etc. Having 2 DAMS and over the last 3 years i still struggle with the way this thing is best set up.
For example TNT's filters, which one (F4 to F7) are you analysing?
 

TNT

Member
Joined 2003
Paid Member
I understand you - it's really not well conceived. The system has kind of 2 names for each of the 4 different possible filters - as I understand it.

F4=Linear
F5=...

And you are to use F4 alt. Linear depending where you are in the terminal interface. It's really very poor UI design I'm afraid. But, if it was hard to do, it should be hard to use - as they say in the GUI business ;)

My TNT441Lin2 filter is "Linear" = F4. And only so far for 44,1. So if you play F4 at 96 Khz it's not mine. You see, there is one Linear/F4 version for each sampling-frequency; Linear 44,1 Linear 48 Linear 96 etc...

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