Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 KHz

[kronzilla]

Maybe little offtopic, but have a question, i recently bought an Aune S5, wich software version is the best, also for nos 16bit. I have the sk lite to control the dam 1024 vers 4.
Thank you.

 

[kronzilla]

Sorry version 5

 

[stephengrenfell]

I have a dam1021 running uManager Rev 1.06 and Firmware 1.05

I want to try some DSD audio files. With DSD64 initially there is (perfect) sound (for maybe 30 seconds) and then it looses lock (led on dam1021 flashing), thereafter I have to power cycle the dam1021 to get sound evan in PCM.

It's not clear to me if this version of Firmware 1.05 supports DSD, as on the Soekris downloads page it says "full firmware and filters ver. 1.06 Added DSD support + minor improvements" for "fpga firmware ver. 1.05" there is no mention of DSD. Which implies I need to update to 1021full_106.skr

So I try to updatee to 1021full_106.skr - connecting to the uManager and downloading of the file then updating seems to go ok . But then when I power cycle the uManager and Firmware version numbers have not changed.

ON initial connection uManager says

dam1021 uManager Rev 1.06 20160304  FPGA Rev 1.05  Press ? for help.

downloading and updating

# download

Start sending file using XMODEM/CRC protocol.
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCze 604160 Bytes.

#

# update
uManager Firmware Update, are you sure ?   Updated, resetting.

R1.06
I3
L000
F5
V+00
I3
I0
L044
L000


R1.06
I3
L000
F5
V+00
I3
I0
L044

Then after power cycle

dam1021 uManager Rev 1.06 20160304  FPGA Rev 1.05  Press ? for help.

What am I doing wrong ?;

Thanks.

 

[TNT]

I would think that ""Added DSD support +..." does indeed mention "DSD"... no?

//

 

[zfe]

The rev Rev 1.06 update only updates uManager to Rev 1.06. The fitting FPGA firmware is Rev 1.05. That is OK.
I have no problems with DSD with this.

 

[stephengrenfell]

The rev Rev 1.06 update only updates uManager to Rev 1.06. The fitting FPGA firmware is Rev 1.05. That is OK.
I have no problems with DSD with this.

Ok thanks that's useful to know zfe, and of course explains why the version numbers didn't change when I tried to update....

Now I need to look at why it doesn't seem lock and be stable with DSD when it's ok with PCM at all rates.

 

[NETT1969]

No SPDIF lock after uploading NOS filter

Thanks to several threats here I was finally able to get the proper USB/RS232 cable connected to the dam 1021. Right after that I uploaded the NOS filter published by Spzzzzkt back in 2015 but after power cycling the unit the SPDIF signal doesn't lock anymore.


I reverted to the original Soekris filter and the signal locks OK again.

Has anyone seen this problem before?


Thanks.

 

[randytsuch]

Thanks to several threats here I was finally able to get the proper USB/RS232 cable connected to the dam 1021. Right after that I uploaded the NOS filter published by Spzzzzkt back in 2015 but after power cycling the unit the SPDIF signal doesn't lock anymore.


I reverted to the original Soekris filter and the signal locks OK again.

Has anyone seen this problem before?


Thanks.

From what I remember, if the filters used are not compatible with the fpga firmware, you can "break" the dac, and that might cause it not to lock.
Those 2015 filters might be for an older firmware.

 

[NETT1969]

From what I remember, if the filters used are not compatible with the fpga firmware, you can "break" the dac, and that might cause it not to lock.
Those 2015 filters might be for an older firmware.

Thanks a lot, I will search for newer NOS filters.

 

[living sounds]

Hi Søren,

are you still planning on doing a SAR ADC? I still think there would be a market for it (and I would certainly buy it).

 

[soekris]

Hi Søren,

are you still planning on doing a SAR ADC? I still think there would be a market for it (and I would certainly buy it).

Yes, I have stuff in my CAD system and are moving forward.... Not sure how to sell them if I make one, it will probably not be a DIY project, although I'm considering a special deal for people her....

 

[TNT]

Nice!!!

//

 

[living sounds]

Yes, I have stuff in my CAD system and are moving forward.... Not sure how to sell them if I make one, it will probably not be a DIY project, although I'm considering a special deal for people her....

Exciting!

From my perspective this is predominantly a pro audio device and would make most sense as a finished unit with input clipping protection and a state of the art input stage. DC coupled and offset taken care of with a servo (that's how Prism Audio does it).

As for marketing, news would spread quickly through message boards. I know I would create shoot outs and post these online, and other people would as well. And I would tell anyone in the studio world who would listen if this audibly beat the current S-D AD converters in the same way the DAM1021 beats the S-D DACs.

Maybe the tricky part is the filter? TNT's creation earlier this year took the DAM1021 to a whole new level. It would probably be a good idea if it were user programmable. And I guess there will be an analog filter stage in front as well...

 

[kenneth_obee]

Hi everyone,

I got a problematic dam1021, it always jump to prompt when I connect the serial without pressing +++. Moreover, the input always set to I3, and the firmware revision is incorrect. I have upgraded the firmware to 1.21 (latest) still no luck.

(The first one is a normal dam1021, which can show the revision correctly. The lower one is the one with problem)

Before upgrading the firmware to 1.21, it was v0.8

 

[kenneth_obee]

If it shows rev F.F, then the FPGA image is not downloaded correctly. The uManager should always work, even with incorrect FPGA image.

The image get downloaded directly to the FPGA Flash, it's not like it get loaded afterwards.... I'm using the same source code as for my line of embedded computers, so it should be ok.

I'm using HyperTerminal on Windows, that I never had any problems with.

The same issue was mentioned in post #1434.
The rev F.FF means problem in firmware...

I tried to flash the firmware to 0.9, then to 1.06 then to 1.21 but still the firmware is F.FF.

Soren, is there a way to reset this thing? Thanks !

 

[soekris]

The same issue was mentioned in post #1434.
The rev F.FF means problem in firmware...

I tried to flash the firmware to 0.9, then to 1.06 then to 1.21 but still the firmware is F.FF.

Soren, is there a way to reset this thing? Thanks !

No need to reset anything, if uManager runs, you can download new firmware.... Are you remembering to use the "update" command after downloading new firmware and then do a power cycle ? The 2nd picture still show rev 0.8....

 

[kenneth_obee]

No need to reset anything, if uManager runs, you can download new firmware.... Are you remembering to use the "update" command after downloading new firmware and then do a power cycle ? The 2nd picture still show rev 0.8....

The second pic was the very beginning.
I take off the board and clean up. Now it is back to normal.
Thanks

 

[NickKUK]

Interesting: US6307490B1 - Digital to analog converter trim apparatus and method
- Google Patents

I see that the 1999 patent for R2R resistor trimming has just expired.

 

[analog_sa]

I see that the 1999 patent for R2R resistor trimming has just expired.

That must be very exciting but cannot see it as being useful to this particular thread or audio dacs in general. Has this patent been ever implemented anywhere?

 

[NickKUK]

That must be very exciting but cannot see it as being useful to this particular thread or audio dacs in general. Has this patent been ever implemented anywhere?

The Holo Audio May uses R2R trimming and states it is patent pending - given there's prior art that has now expired, I wonder how valid that claim is. It does open the door for other R2R manufacturers to review the patent positions and possibly offer R2R trimming.

The R2R trimming would help the linearity (a weak spot in the soekris and others).