• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

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

Jump to Latest
J

Juhleren

Member
Joined 2011
nige2000 said:
my gut feeling would be that the resistor difference wouldnt be the anywhere near the weakest link of this board, if it were me id go with the cheaper one and put the cash difference into mods
either is fine once powered by a lifepo4 cell slightly prefer the diyinhk atm
like a virtual gnd?


the cells i use are generic from
https://www.reichelt.com/index.html?ACTION=3;ARTICLE=86863;SEARCH=LIFEPO4 26650FPZ
im too impatient to order from china
they come in green though

1.2v reg is far more influential than i had first thought
cant figure why an ldo wasnt used here

there is no buffered outputs on our modded builds so +/- 5v isnt needed
need a minimum of 3 + cells for decent sound and more than 5 cells id imagine it would be a struggle to notice any benefit

Randy logged most of what we did here
randytsuch's audio page: Soekris R2R Dam Dac - Modding
Click to expand...

Thanks a bunch Nige2000! What a sift and helpful reply. I didn't expect a reply this soon -DIY must be the truest of all communities :)

OK, so 5% it will be -unless only the 2% is available.

Regarding grounding, as for the (starter) 0-15VAC trafo supply, I imagined to connect global ground between the caps and thereby have the supply's voltage swinging around that to give the +/- VDC at the other end of the caps.

I'll dive into your log and search my way through!
If (or rather when) I go the Battery route, I'm almost certain that I I'd go for 5 or more cells. Once modding, there is little sense in holding back, right :)

Those cells seems to be much better prices than what I found on Ebay.

Great to know that the diyinhk has the edge. They also a bunch of regulators that should make it easy to get the 3.3V for the cells.

Thanks and all the best,
 
J

Juhleren

Member
Joined 2011
nige2000 said:
tbh i found using ac input a complete waste of time
most of the original issues was related to vref
id imagine 1021 v2/3 is much better
almost a year ago i was trying to figure out how to get lifepo4 into vref
i knew it would be crucial, but did not realise it would completely turn it inside out
i only know of 4 builds done with lifepo4 and two of them are mine
its a shame more wont experiment
Click to expand...

Yes, version one seemed to have some hf noise issues that v2/3 have to a lesser degree -if not completely eliminated. I'll definitely try the dam as designed before proceeding with surgery on its internals. But me being me, I probably have to Cell it out -at least to know what can be achieved.

Experimenting is what DIY should be all about! -And that's also where DIY can go so much further than commercial offerings that have to undergo extensive health and safety certifications.

As for your experiments with lifepo4 cells: have you ever tried putting a choke or a resistor between the charging regulator and the cell? I imagine that it might further improve the isolation effect of the cells' extremely low internal resistance... Just wondering of course...

cheers,
 
O

oll740

Member
Joined 2014
Hi,
Could anyone of you please tell me when will appear the information about
"Upcoming features (through user-performed firmware upgrade)
2. Filter cascading for digital crossover"
(https://hifiduino.wordpress.com/2015/01/30/building-soekris-r-2r-dac/)
And is there an answer to a question
“Someone knows how to set the delay in the FIR filter for the dam1021?”
That I have asked a long time ago 30.10.2015 :(

I fully understand a workload of an Author and really thankful for this project.
However I still hope to receive an answer.
Possibly somebody have tried to use FIR1 for constructing a crossover.
I will be thankful for help.
 
K

katariat

Member
Joined 2014
need some quick help on rcore wiring. We were trying to finish the power supply section for the dac build. Please see attached. When we connected the black and white or the red and blue combination we were not getting any output at either of the brown/ brown or the grey/grey combination. thanks
 

Attachments

  • 20160130_150326.jpg
    20160130_150326.jpg
    478 KB · Views: 820
G

Green77

Member
Joined 2007
Hi all.
Today i was trying to rescue my dam1021 that i destroyd trying to change the brooken memory ic last friday. I manage to solder the ic in, i can upload fw and fpga file. But it won't save it. Next time the fpga say rev 0.00. Anyway, it is a small step forward, last friday it was totaly blank screen trying to "talk" with it from UC.
Wonder if it is some more dammage to the traces or if i have a bad solder?

Best regards // Daniel
 
S

soekris

Member
Joined 2009
soekris.dk
Paid Member
I'm preparing the next dam1021 firmware release in a few days, will include full DSD support up to DoP128 and native DSD256 over the I2S interface, limited only by the USB to I2S interface's capabilities. The new DSD functionality will convert DSD directly to 352K PCM using a 1024 tab FIR decimation filter.

I have a question: It's actually the USB to I2S interface that handle DoP, the question is if there is a need for DoP support over SPDIF interface, if so I need to do my own DoP firmware.... So do anybody have any hardware that actually outputs DoP over SPDIF ?

I would also like to take suggestions about any simple functionality that need to be added before release, like to have the "V00" status output to indicate no signal, which will be added. Any suggestions have to be simple and easily tested here without additional hardware.
 
K

kenneth_obee

Member
Joined 2010
soekris said:
I'm preparing the next dam1021 firmware release in a few days, will include full DSD support up to DoP128 and native DSD256 over the I2S interface, limited only by the USB to I2S interface's capabilities. The new DSD functionality will convert DSD directly to 352K PCM using a 1024 tab FIR decimation filter.

I have a question: It's actually the USB to I2S interface that handle DoP, the question is if there is a need for DoP support over SPDIF interface, if so I need to do my own DoP firmware.... So do anybody have any hardware that actually outputs DoP over SPDIF ?

I would also like to take suggestions about any simple functionality that need to be added before release, like to have the "V00" status output to indicate no signal, which will be added. Any suggestions have to be simple and easily tested here without additional hardware.
Click to expand...

Really appreciate your effort, the V00 feature is great!

To me, DoP over SPDIF is no need, but I know several products in the market supports this, so may be there's a need.

I have a silly question, for spdif1 & 2, are they non-isolated? (seems non-isolated)
 
S

soekris

Member
Joined 2009
soekris.dk
Paid Member
kenneth_obee said:
Really appreciate your effort, the V00 feature is great!

To me, DoP over SPDIF is no need, but I know several products in the market supports this, so may be there's a need.
Click to expand...

Yes, there are several products that can receive DoP over SPDIF, but are there any sources ???

I have a silly question, for spdif1 & 2, are they non-isolated? (seems non-isolated)
Click to expand...

Yes, they go directly to the FPGA, and should be isolated somewhere, either with a transformer or toslink receiver, see example schematics in manual.

Btw, a better Coax interface than earlier suggested would be using a high speed RS422 receiver, like a MAX3280E or ISL3280E, will do example schematics at some point....
 
K

kenneth_obee

Member
Joined 2010
soekris said:
I'm preparing the next dam1021 firmware release in a few days, will include full DSD support up to DoP128 and native DSD256 over the I2S interface, limited only by the USB to I2S interface's capabilities. The new DSD functionality will convert DSD directly to 352K PCM using a 1024 tab FIR decimation filter.

I have a question: It's actually the USB to I2S interface that handle DoP, the question is if there is a need for DoP support over SPDIF interface, if so I need to do my own DoP firmware.... So do anybody have any hardware that actually outputs DoP over SPDIF ?

I would also like to take suggestions about any simple functionality that need to be added before release, like to have the "V00" status output to indicate no signal, which will be added. Any suggestions have to be simple and easily tested here without additional hardware.
Click to expand...
So do you mean all the DSD, no matter it is DSD64, 128 or 256, will all be converted into 352K PCM?
 
D

Dimdim

Member
Joined 2008
soekris said:
I'm preparing the next dam1021 firmware release in a few days, will include full DSD support up to DoP128 and native DSD256 over the I2S interface, limited only by the USB to I2S interface's capabilities. The new DSD functionality will convert DSD directly to 352K PCM using a 1024 tab FIR decimation filter.

I have a question: It's actually the USB to I2S interface that handle DoP, the question is if there is a need for DoP support over SPDIF interface, if so I need to do my own DoP firmware.... So do anybody have any hardware that actually outputs DoP over SPDIF ?
Click to expand...

IMHO no, you should not waste your time on a feature that might be useful to a handful of people. Most audiophiles believe that native DSD sounds better than DoP anyway. :p

soekris said:
I would also like to take suggestions about any simple functionality that need to be added before release, like to have the "V00" status output to indicate no signal, which will be added. Any suggestions have to be simple and easily tested here without additional hardware.
Click to expand...

The "V00" feature is a very welcome addition. I would welcome a command equivalent to the "filters" command of the uManager prompt.
 
C

comickitkit

Member
Joined 2013
Reference Voltage to Shift Registers

Hi nige,

why don't you to use 4VDC from batteries supply? found you are using 3.3vDC instead of?

nige2000 said:
tbh i found using ac input a complete waste of time
most of the original issues was related to vref
id imagine 1021 v2/3 is much better
almost a year ago i was trying to figure out how to get lifepo4 into vref
i knew it would be crucial, but did not realise it would completely turn it inside out
i only know of 4 builds done with lifepo4 and two of them are mine
its a shame more wont experiment
Click to expand...
 
N

nige2000

Member
Joined 2013
comickitkit said:
Hi nige,

why don't you to use 4VDC from batteries supply? found you are using 3.3vDC instead of?
Click to expand...

There are many reasons
But there is only one reason that matters

Found no audible differences between running at 4v or 3.3v

Because of that the other reasons become relevant

The 26650 lifepo4 cells native voltage range is between 2.5 to 3.6v and 4v is out of the comfort zone

Only need two main 3.3v + and - linear supplies and a linear 1.2v reg for whole DAC

Which is more simple
 
You must log in or register to reply here.
Top Bottom