You already offered!You were first to offer to test and you are second on the interested list. In my book, that makes you the prime candidate.
<cheeky>Ian, please hurry up and send him the board. Let's get this show on the road..... LOL.</cheeky>
PS. I've added myself to the list for 2 boards. I'll re-work my balanced dual AD1865 DAC with one of the boards and finally build the 1704 I've been putting off forever.
Yes, merlin el mago is the first one offering evaluate the daughter board on 1704. clivem is the second, but he recommend regal. regal said his time off from work is about to end
merlin el mago,
Is your 1704DAC ready to open the input ports? It comes with DF? The daughter board needs to be placed between the I2S source and the 1704.
Please let me know your configuration.
Thank guys.
Ian
Thank you so much merlin el mago for offering evaluating the daughter board for the community on your PCM1704 DAC. Please send me your shipping address to iancanada.mail@gmail.com.
I'll assemble another board and send it to you.
Happy New Year.
Ian
TDA1541 can accept standard I2S signal. So normally we do not need the I2S to PCM daughter board to interface fifo with it.
However, it has a L/R simultaneous input mode(OB/TWO connected to VDD1) which I thinks might be better option for SQ. But the data format has to be in offset binary.
I know there are a lot of 1541 expert over there, any comment on this issue?
Regards,
Ian
Hi Ian,
I'm no expert but I've been listening the the TDA1541A running at 16bit/44.1k using the FIFO for a bit over a month now. With the I2S to PCM convertor board you get the added "advantage" of oversampling of up to 8x (352.8k).
The 1541A will accept up to 4x oversampling in I2S mode, so the oversampling can be done before the FIFO, the benefit being less added jitter after the FIFO.
So you have a few options:
- Use FIFO connected directly to 1541A using 16/44.1
- Oversample 4x before the FIFO then to the 1541A
- Oversample after the FIFO up to 8x but with the added jitter of conversion.
Hope this helps. If i've made any errors anyone - please correct me.
Ryan
Thanks Ryan,
In this case, we need running 1541 at L/R simultaneous input mode(OB/TWO connected to VDD1). But the data format has to be in offset binary, if I'm not wrong. Do you have any experience on this offset binary format?
Happy new year
Ian
Happy new year to you Ian!
Im afraid we have reached the extent of my knowledge on this subject.
No i havn't used the 1541 in offset binary format.
Ill have to do some study on the subject.
happy new year all.
Ryan
The L/R simultaneous mode is probably the most desirable way to use your board with the TDA1541. Very few TDA1541 designs use offset binary because of the complexity of the glue logic required to do this.
I have never tried it, but my understanding is that offset binary is the same as two's compliment, just with the MSB inverted.
These two links seems to explain it well.
C3Dformat
Offset binary - Wikipedia, the free encyclopedia
I will be interested to try offset binary with the TDA1541 this when the boards are finally ready.
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Hello,
I was playing with the raspberry pi for a day, now I have a remote controlled (by and android tablet) media player, with BAD sound output. Now I need a USB to I2S adapter. Which one do you suggest ? It should work with the standard libraries, with not special driver. Smaller is better. Than I will need this board between the I2S and my AD1865 DAC.
Thanks,
JG
I was playing with the raspberry pi for a day, now I have a remote controlled (by and android tablet) media player, with BAD sound output. Now I need a USB to I2S adapter. Which one do you suggest ? It should work with the standard libraries, with not special driver. Smaller is better. Than I will need this board between the I2S and my AD1865 DAC.
Thanks,
JG
Thanks erin,
In this case, it seems I need to include the offset binary decoding into my FPGA design for TDA1541/A. Hopefully, we still can get drop of juice from it
.Regards,
Ian
Oversampling/NOS
So this I2S to PCM convertor cannot be used in pure NOS application due to oversampling? Oversampling is a forced operation or could be turned off?
So this I2S to PCM convertor cannot be used in pure NOS application due to oversampling? Oversampling is a forced operation or could be turned off?
Hi new2hifi,
Since the TDA1541A accepts the I2S format directly, there is no point converting from I2S to PCM if you want to run the 1541 in NOS.
I really don't know enough about the PCM format to comment on any advantages. Maybe somebody else can advise.
Ryan
Thanks erin,
In this case, it seems I need to include the offset binary decoding into my FPGA design for TDA1541/A. Hopefully, we still can get drop of juice from it
Regards,
Ian
Yes that would be very good of you to do so.
Please allow me to advise.
This board Ian is making will allow the option of a simultaneous output of offset binary Left and Right Data. For TDA1541 enthusiasts, and tinkerers, this will allow a person to create a dual mono TDA1541 board. Also possible is a dual differential, or balanced output TDA1541 board.
I know many people will be interested in these possibilities.
And it may be worth nothing, but I have read reports from those that have tried it, that the offset binary data input sounds better than the i2s.
I don't know, but I am keen to try it.
It will also allow the use of the TDA1540 chip.
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Qusp, the 1541 has limited bandwidth to about 6.5Mhz. The DEM has successfully been clocked from BCK at 2.8Mhz by several members following such designs as member "ecdesigns" (John Brown) has used in the past.