Soekris' DAC implementations

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#441
Hi normundss,

Certainly interested in a GB as well. If possible, would prefer SMD components installed.

Rotary switches you mentioned are available in shorting and non-shorting versions. What are the difference between them & does it matter for this application?

Cheers.
 
#442
As it is a pre also with pot, could it be possible to select the outputs with relays : we can have 3 : it can drive an amp with balanced, a TV with buffered SE or a headphone and an analog pre or any buffer with the non bufered SE ?

two cents, just an idea !
 
#444
normundss said:
Next week I will get price quotes for the boards, then we can do a GB.
Click to expand...

Good news.

By the way:

Shorting = means the contact makes connection with the next pole before breaking the last connection

Non-shorting = means the switch breaks the connection with the current pole, before connecting to the next.

Does anybody have any idea about the implications of these regarding dam1021 input switching with normundss' front panel?
 
#445
normundss said:
Next week I will get price quotes for the boards, then we can do a GB.
Click to expand...

Looking great - i will certainly jump on this GB.

Just one question - to get the spdif 1.2v lifted from ground, then you need to wire from the DAM 1.2v pin+gnd, and wire to the 1.2v input socket on this board?

Also, can you later give us the back-panel / front panel drilling template for the pot/leds and the USB/SPDIF/TOSLINK?, so we'll know how they will be in height/width from eachother.

/Robert
 
#446
leehan said:
Hi normundss,

Certainly interested in a GB as well. If possible, would prefer SMD components installed.

Rotary switches you mentioned are available in shorting and non-shorting versions. What are the difference between them & does it matter for this application?

Cheers.
Click to expand...

Having the SMD components assembled will probably drive the price up quite a bit, and I am not really looking forward to handling parts kits. I can check the costs, but probably it is going to be just the boards.

Nonshorting switches will momentarily switch the inputs to Auto mode while switching, and shorting switches will switch to I2S/USB input. We should all nicely ask Soren to have some input selection delay implemented in firmware, then it will not matter. I have not actually tried it, maybe it is already implemented 😉
 
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#448
Eldam said:
It becomes strange not to say bad with Jean Michel Jarre (a sort of electronic but anti industrial music , to be short an anti Kraftwek !). Now the electronic experimental scene is hided but still active in France, Belgium but don't now elswhere in Europe. When I talk about electronic Scene this is of course not the dance floor rave electronic scene which became very simplist and poor here... IMO !)
Click to expand...

Ultimae Records (based in Lyon) is one of my favourite labels - not what you'd call experimental, but a brilliant down tempo ambient/chill.
Ultimae - Ultimae | records - Releases - Official catalog page - Electronic Music, Ambient, Downtempo, Atmospheric, Electronica, IDM, Progressive Trance - CDs and Digital
https://ultimae.bandcamp.com

Eldam said:
Ah received my Wave I/O to do more serious test and try to upsampling myself with sox !

Terrible as it is time consuming : have still a TDA1541 dac and a AD1862 to finish ! pfffffff !
Click to expand...

Have a look at 2L's sampler page: High Resolution Music DOWNLOAD services .:. FLAC in free TEST BENCH
The track Bøhren/Åserud: Blågutten is a bit ECM-ish, and beautifully recorded. The DXD file is a PCM format - I was able to transcode to a 24/352.8 apple lossless using XLD on Mac.I think J-River might play DSD natively. Regardless, it sounds spectacularly good on the DAM1021.

I been having a play around with approximating the "MP Listening" filter described in the Ayre MP white paper. Not sure that Søren would approve as the filter slope is way less than the 192dB/oct figure he gave for "real filters" 🙂 Anyway it sounds pretty nice, despite being an approximation.

While the “Apodizing” filter proposed by Craven solves many of the problems with digital filters, careful listening tests conducted at Ayre showed that the multiple cycles of post-ringing still created an artificial brightness and an overall confusion to the sound. We therefore sought to combine the best aspects of Craven’s minimum-phase digital filter proposal with a slower roll-off that reduced the overall amount of ringing.

The resulting filter has no pre-echoes, and only about one cycle of post-ringing. This filter is implemented in the “Listen” position of the new Ayre MP disc players. The result is simply the most musically natural digital playback available today.
Click to expand...

I'm down to 2, possibly three cycles of post-ringing and a tiny amount of pre-ringing, as I've had to add a linear phase filter to get the response down above 30kHz.

cheers
Paul
 

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#449
RollE2k said:
Looking great - i will certainly jump on this GB.

Just one question - to get the spdif 1.2v lifted from ground, then you need to wire from the DAM 1.2v pin+gnd, and wire to the 1.2v input socket on this board?

Also, can you later give us the back-panel / front panel drilling template for the pot/leds and the USB/SPDIF/TOSLINK?, so we'll know how they will be in height/width from eachother.

/Robert
Click to expand...

Options to power the input board :

1) Use existing 1.2V and 3.3V power from DAM1021:
  • Connect +1.2V pin of J4 header to PWR +1.2V pin on the dac. There is no need to connect the GND pin.
  • Install and connect J6 jumper (INT_3.3V).
  • Do not install IC1, C3, C4, J7.

2) Use 1.2V from the DAC and separate regulator for 3.3V:
  • Connect +1.2V pin of J4 header to PWR +1.2V pin on the dac. There is no need to connect the GND pin.
  • Do not install J6 jumper (INT_3.3V).
  • Install IC1, C3, C4, J7.
  • Connect +4-16V pin of J7 header to PWR A+ pin on the dac.There is no need to connect the GND pin.

3) Use completely separate 1.2V and 4-16V supplies:
  • Connect J4 header to your 1.2V supply (both + and GND wires)
  • Do not install J6 jumper (INT_3.3V).
  • Install IC1, C3, C4, J7.
  • Connect J7 header to your 4-16V supply (both + and GND wires)
 
#456
robertrowett said:
How do we access the menu to work on filters? I have no experience with computers and haven't used dos since 1987...
Thanks for help on this.
Click to expand...

In uManager type "download" (exactly the same as firmware update). Typing "?" will give you a list of options.

The R2R DAC will respond with:
Code: 
Start sending file using XMODEM/CRC protocol.

As the prompt indicates the file needs to be transfer using xmodem protocol for the upload to succeed.

You then use your terminal program's send file function to upload. Once the file uploads you'll see something like:

Code: 
### Send (X) 1021filt.skr: 10752 bytes, 0:03 elapsed, 3014 cps, 26%

File downloaded and programmed, size 010752 Bytes.
 
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