I've been having a play with creating something close to the Ayre MP Listening position filter described in their MP white paper.
I've used a similar method to POS in that the main filter is minimum-phase, but an additional linear-phase filter is used to control the cutoff slope.
As per the Ayre white paper this filter is -6dB at 22050hz, and -96dB at 44100hz. I'm sure this will give Søren the horrors, but I feel if it's good enough for Charles Hansen to include in a commercial product as the preferred setting it can't be all bad
I've included comparison with POS's filter (pos - blue, my "MixPhase1" filter - red).
Filter Response showing the slower roll-off, and earlier onset of filtering. It's about -1.2dB at 19kHz, so not as ruler flat as POS or stock filters.
IR showing 2, possibly 3 post-ringing cycles on the MP1. Not as good as the 1, possibly 2 cycles of the Ayre. Both POS's filter and my MP1 have a minimal amount of pre-ringing from the use of linear-phase filters.
Step response is similar story to the IR.
How does it sound? I like it, but them I'm biased (and possibly have tin ears).
zipped .skr with MixPhase1 at 44.1 position attached.
This filter sounds really nice. More clarity and less thickness vs the previous one you posted. Great job!
Mixed feelings between POS and MixPhase filters.
MixPhase is like sitting with the band in an acoustically UNTREATED room, unwanted reflections thing. Significantly stronger bass, fuller bodied instruments, but not precise.
POS is like listening to the band from a distance in a acoustically TREATED room, easier to distinguish instruments, but thinner and not as lively.
It may be the extra bass creeping into the mids with MixPhase... or my headphones.
(Should we discuss explosive topic of filter impressions in a separate thread?)
MixPhase is like sitting with the band in an acoustically UNTREATED room, unwanted reflections thing. Significantly stronger bass, fuller bodied instruments, but not precise.
POS is like listening to the band from a distance in a acoustically TREATED room, easier to distinguish instruments, but thinner and not as lively.
It may be the extra bass creeping into the mids with MixPhase... or my headphones.
(Should we discuss explosive topic of filter impressions in a separate thread?)
A quick question:
Have been running the r-2r with spdif input. Just received a good 3.3v ldo board and will try i2s.
My i2s out interface is a Gustard U12.
The case is that it has HDMI interface out.
The pinout is like this:
How do I connect this to the r-2r dac?
Thanks in advance.
BTW: I also have a hdmi screw terminal female type intended for the purpose of connecting to the dac.
CIE-Group Conec2 HDMI to Screw Terminals PCB Module CLB-HDMIPCBUNIT
Have been running the r-2r with spdif input. Just received a good 3.3v ldo board and will try i2s.
My i2s out interface is a Gustard U12.
The case is that it has HDMI interface out.
The pinout is like this:
How do I connect this to the r-2r dac?
Thanks in advance.
BTW: I also have a hdmi screw terminal female type intended for the purpose of connecting to the dac.
CIE-Group Conec2 HDMI to Screw Terminals PCB Module CLB-HDMIPCBUNIT
Attachments
Your I2S source uses differential output, most likely LVDS. So you would need a 4 channel LVDS receiver to convert the signals. Twisted Pear Teleporter module might do the trick if you don't want to roll your own, but first make sure that the I2S output indeed uses LVDS signaling.
Problem solved
I pulled a really old PC out of the basement, with a real serial port, and everything worked immediately.
Thanks for the help, but it was a hardware thing indeed, now this slow and old PC has a new live as update machine for a DA
You need one LVDS receiver.
The only one I found with same pinout is this I2S‚Æ�AI2S‚à‚Ç‚«‚Æ�A S/PDIF‚ɂ‚¢‚Ä
Another receivers with different pinout are. Perhaps would be possible to modify it.
Aune kit Module d'entre HDMI vers I2S - Audiophonics
ºÍ§Ó*µ响
K&K Audio | Digital Audio
Also you can use The Teleporter with modifications
Teleporter Digital Transfer Module
A good solution may be to replace the HDMI connector of Audiophonics receptor, for which you already have.
Regards
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Not a chance. Too many whingers and whiners who's main pleasure is bitching about methodology and setup. If you want measurements DIFY.
I've started a filter thread here:
http://www.diyaudio.com/forums/digital-line-level/269776-filter-brewing-soekris-r2r.html#post4224123
http://www.diyaudio.com/forums/digital-line-level/269776-filter-brewing-soekris-r2r.html#post4224123
spzzzzkt (Paul)! I am asking soekris, who has mentioned many times that this is a commercial product and usually manufacturers publish such measurements. Except post 1, he has not published any data. He can also include that at the end of the Manual.
Neither I own his module nor I am equipped to do such measurements. Thus, I am asking soekris.
Asking for measured Frequency response and Impulse response is not a challenge to him or to DAC but it will indeed help interested persons to understand what they are getting into.
Right now we are just seeing the software analysis of filters (I appreciate your contribution) but I wish to see the real measurements of dam1021 as it is being offered. As we say in America, "where the rubber meets the road"
http://www.soekris.dk/dam1021.html
I don't know why you're so focused on frequency response, in a R-2R DAC is kinda depending on the digital filters as it will otherwise be linear like a ruler from DC to where it hit the analog lowpass filter, which is something like -3 dB 150 Khz, a little lower on the buffered output.
If the software is otherwise bugfree, you can expect the hardware to measure exactly like the software....