If you omit all the parts in the schematics for the power supply section then yes that should be fine.
Hi Luke,
D3 has the edge with my setup. And now that im running the D3 in a differential configuration I like it even better.
Hi Myint67,
Sorry about this, I know its not the most DIY friendly design. I was aiming for a very compact design minimizing current loop area, etc. I hope you get it working ok.
Hello ryanj , can you share some info about the differential config?
I would like to try it since i have another D3 empty pcb ready lol!
Is is not dificult... at the beginning it seems dificult but in the end you will see it is not that hard![emoji846]
Hi pistollero,
I made another I2S2SIM PCB that has a dual inverter chip (SN74LVC2GU04DBVR) that inverts both left and right data lines and has enough outputs to drive 4 D3 PCBs. One D3 PCB receives the left data and inverted left data (pin 3 and 4), and the other D3 PCB has right data and inverted right data. The output of each D3 is going into a transformer (LL1678) with the center tap going to a -4mA CCS with an IV resistor of 60R on each output.
I also plan to add another two more D3 PCBs to make a paralleled differential configuration. This would give 16mA full scale current output for each channel allowing for a lower value IV resistor and more current to drive the transformer, which hopefully will result in better sound. Thats the plan anyway, ill post my findings here eventually.
Hi Ryan, I would be curious to hear your thoughts on parallel dac chips. Mine is not so favourable, but I have only heard it with AD1865 not TDA1541A. I found it made the sound thicker, muddy and less articulate, single chip was crisper and nicer. I still plan to build your V1 BTW. I ended up buying a built AYA II and made another amp instead
Hi Luke,
I would have thought that when paralleling DACs with bit averaging occurring it should theoretically lead to a more accurate waveform. But I guess Ill just have to give it a go to know for sure. Although, technically what I have now with running in a differential configuration its still paralleling 2 DACs although just inverted, and if the sound im getting now is anything to go by then I am expecting a good result.
You still have that V1 PCB. I think you should try a D3 instead.
I would have thought that when paralleling DACs with bit averaging occurring it should theoretically lead to a more accurate waveform. But I guess Ill just have to give it a go to know for sure. Although, technically what I have now with running in a differential configuration its still paralleling 2 DACs although just inverted, and if the sound im getting now is anything to go by then I am expecting a good result.
You still have that V1 PCB
. I think you should try a D3 instead. 
Hi Ryan
I just sent you PayPal for my populated D3 and I2S to SIM.
I had to resist the temptation to order additional boards with all this talk of exotic differential builds going on.
This will be my first DAC build and I am trying to remove as many opportunities to screw it up as possible. That’s the main reason I went for the populated boards. I’m hoping to make as many things plug and play as possible.
It’s also why I will not be implementing the I2S to SIM right away. I figure the simplest setup is the way to go at first.
When I initially inquired about trying to take on this project you responded:
Things you will need for the D3 build are:
- 26V Floating power supply (no reference to GND)
- 5V supply
- output stage
I saw you posted some details earlier in the thread about a power supply that you use in your setup. I’m trying to sort this out myself and would benefit from any guidance that could be offered here.
I saw several posts of other members D3 builds that appear to utilize the Salas SSLV and Reflektor boards to power their projects depending on their requirements for output stages and the like. They are well supported designs which would help me a lot.
I have two partial SSLV + and - rail kits that I am hoping to sort out at least the 5V supply with.
I also recently ordered some super regulator boards from the DIY store that I’m waiting for. I’m not sure if these are necessarily better to use or not. They appear to also have excellent support.
Both designs would seem to allow for creating a 26V supply. I’m not sure about the need of making it a floating supply. My only experience in that area is with using NIMH batteries for phono amps and the like.
I want to complete my Shigaclone transport to use with this DAC and it would require some sort of receiver for the SPDIF output that the Shigaclone is limited to. I haven’t figured out what to use as a receiver yet but I am thinking I would like other input options besides coax SPDIF on the receiver.
When Ian Canada recently announced the release of his ReceiverPi I inquired about using it with the Shigaclone and D3 and mentioned that you recommended simultaneous input for the D3.
Ian suggested I would achieve the best results by using the ReceiverPi+FifoPi+PCM boards...stating the PCM could provide simultaneous input for the D3.
This seems too complicated for me and a considerable additional investment. Not that I am against spending money to achieve good results. It just seems too much to deal with in a first DAC build.
I’m not sure if Ians older SPDIF interface board can be used alone or if it requires the use of his FIFOII and clock board which seem to still be available. If it requires the two additional boards, again it seems too complex and costly for a first DAC attempt.
Any suggestions for a supported good quality receiver solution would be appreciated.
I am hoping for a start that it won’t be difficult to implement a transformer based output stage. I already added some Jensen transformers on the output of my DCB1 preamp for some extra gain and was happy with the results. I will be reading up on the CEN/SEN as well.
I’m wondering what the D3 and I2S to SIM boards will come with for power supply and signal input and output connections? I see a lot U.FL coaxial cable and sockets being used for signal connections on DAC projects and a variety complex headers.
I just sent you PayPal for my populated D3 and I2S to SIM.
I had to resist the temptation to order additional boards with all this talk of exotic differential builds going on.
This will be my first DAC build and I am trying to remove as many opportunities to screw it up as possible. That’s the main reason I went for the populated boards. I’m hoping to make as many things plug and play as possible.
It’s also why I will not be implementing the I2S to SIM right away. I figure the simplest setup is the way to go at first.
When I initially inquired about trying to take on this project you responded:
Things you will need for the D3 build are:
- 26V Floating power supply (no reference to GND)
- 5V supply
- output stage
I saw you posted some details earlier in the thread about a power supply that you use in your setup. I’m trying to sort this out myself and would benefit from any guidance that could be offered here.
I saw several posts of other members D3 builds that appear to utilize the Salas SSLV and Reflektor boards to power their projects depending on their requirements for output stages and the like. They are well supported designs which would help me a lot.
I have two partial SSLV + and - rail kits that I am hoping to sort out at least the 5V supply with.
I also recently ordered some super regulator boards from the DIY store that I’m waiting for. I’m not sure if these are necessarily better to use or not. They appear to also have excellent support.
Both designs would seem to allow for creating a 26V supply. I’m not sure about the need of making it a floating supply. My only experience in that area is with using NIMH batteries for phono amps and the like.
I want to complete my Shigaclone transport to use with this DAC and it would require some sort of receiver for the SPDIF output that the Shigaclone is limited to. I haven’t figured out what to use as a receiver yet but I am thinking I would like other input options besides coax SPDIF on the receiver.
When Ian Canada recently announced the release of his ReceiverPi I inquired about using it with the Shigaclone and D3 and mentioned that you recommended simultaneous input for the D3.
Ian suggested I would achieve the best results by using the ReceiverPi+FifoPi+PCM boards...stating the PCM could provide simultaneous input for the D3.
This seems too complicated for me and a considerable additional investment. Not that I am against spending money to achieve good results. It just seems too much to deal with in a first DAC build.
I’m not sure if Ians older SPDIF interface board can be used alone or if it requires the use of his FIFOII and clock board which seem to still be available. If it requires the two additional boards, again it seems too complex and costly for a first DAC attempt.
Any suggestions for a supported good quality receiver solution would be appreciated.
I am hoping for a start that it won’t be difficult to implement a transformer based output stage. I already added some Jensen transformers on the output of my DCB1 preamp for some extra gain and was happy with the results. I will be reading up on the CEN/SEN as well.
I’m wondering what the D3 and I2S to SIM boards will come with for power supply and signal input and output connections? I see a lot U.FL coaxial cable and sockets being used for signal connections on DAC projects and a variety complex headers.
I put an ad up in the swap meet and scored a first generation Ian’s SPDIF FIFO with an upgraded Crystek reclock and isolator board.
Not sure I’ll use the isolator, but its an option.
Everything should come assembled and ready to plug into the D3. That’ll give me less to worry about.
I suppose my receiver question is answered.
Now on to sorting out power supplies and the output stage.
I did some research in the Salas SSLV thread, my understanding is that it is a floating supply as long as I don’t give it a ground reference to the chassis.
Not sure I’ll use the isolator, but its an option.
Everything should come assembled and ready to plug into the D3. That’ll give me less to worry about.
I suppose my receiver question is answered.
Now on to sorting out power supplies and the output stage.
I did some research in the Salas SSLV thread, my understanding is that it is a floating supply as long as I don’t give it a ground reference to the chassis.
Yeah id go for V2 over V1. The signal attenuates were a nice addition, and the power supply seemed to be a step up for me as well.
Hi chromenuts,
You could power the 5V inputs on both the D3 and the I2S2SIM PCB with the same 5V supply, total current wound only be around 30mA.
CEN/SEN is a great choice.
You could just as easily solder some wire to the pads and it will work, but the line impedance wont be 50 ohms. So you may get reflections etc, but then it may not even effect the sound. U.FL is the way to go IMO.
For the power input I use these connectors: B2B-XH-A(LF)(SN)
B2B-XH-A(LF)(SN)
Keep it simple to start with, a simple CRC and LM317 will suffice. The 26V supply has good noise rejection, I've used the nosiest supply and compared it with batteries and there was only a very slight difference that I detected.
You could power the 5V inputs on both the D3 and the I2S2SIM PCB with the same 5V supply, total current wound only be around 30mA.
CEN/SEN is a great choice.
You could just as easily solder some wire to the pads and it will work, but the line impedance wont be 50 ohms. So you may get reflections etc, but then it may not even effect the sound. U.FL is the way to go IMO.
For the power input I use these connectors: B2B-XH-A(LF)(SN)
B2B-XH-A(LF)(SN)
I tried simulating the power supply, unfortunately MicroCap12 doesn't have the model for LM317.
IIRC, there's no good models for LM317 for Ltspice either.
I was going to see what direction voltage flow through the 22uF filmcaps. Reason being that usps seem to have lost the package with parts my friend sent me.
I do have some nice 22uF/12.5V Panasonic polymer polarized caps (in the same package-style as a tantalum cap ) that I could use.
If the caps need to be bipolar, I could two os-con (47uF, not sure how close the values need to the 22uF) back to back.
Or I can use Nichicon muse BP 22uF.
IIRC, there's no good models for LM317 for Ltspice either.
I was going to see what direction voltage flow through the 22uF filmcaps. Reason being that usps seem to have lost the package with parts my friend sent me.
I do have some nice 22uF/12.5V Panasonic polymer polarized caps (in the same package-style as a tantalum cap ) that I could use.
If the caps need to be bipolar, I could two os-con (47uF, not sure how close the values need to the 22uF) back to back.
Or I can use Nichicon muse BP 22uF.