Hello Friend,
I'm looking for an I2S DAC chip that can be used with the Cmedia CM108b (USB to I2S).
So far I've been looking at TI DACs because I'd like >2V Vrms output level. However it seems in "H/W control mode" (meaning no dedicated microcontroller), the CM108b's masterclock (x256) does not match what the DACs can handle (x64). Do you have any tips for a readily available DAC IC that is better than the CM108b's internal one?
Thank you very much.
I'm looking for an I2S DAC chip that can be used with the Cmedia CM108b (USB to I2S).
So far I've been looking at TI DACs because I'd like >2V Vrms output level. However it seems in "H/W control mode" (meaning no dedicated microcontroller), the CM108b's masterclock (x256) does not match what the DACs can handle (x64). Do you have any tips for a readily available DAC IC that is better than the CM108b's internal one?
Thank you very much.
May as well use the dac already inside CM108B. Isochronous USB with a PLL is pretty old technology. Sending a good dac chip a jittery clock cannot be expected to produce an especially good result.
TDA1387 works fine (sounds fine) even when fed with a somewhat jittery clock and it doesn't need an MCLK. But its not a one-stop-shop kinda chip, you need to add I/V and filtering externally. You could have a look at TDA1311 too though I can't vouch for how it sounds, it includes the I/V stage on-chip.
Thank you very much! I will have a look at them.
Do you have any recommendations for an alternative cheap USB solution?
Do you have any recommendations for an alternative cheap USB solution?
I have tried various USB boards. The best off the shelf unit so far is I2SoverUSB, especially with even better external clocking (the standard clocks are very good though, NDK SDA). I2SoverUSB - I2S over USB Audio ...IME its best to save one's pennys and buy only good stuff at little at time as it becomes affordable. IMHO buying and then tossing junk all the time is not a better solution in the long run.
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Thanks Mark. I'm designing my own solution. The CM108B is readily available to me even for assembly by jlcpcb for under $2. The XMOS XU208 would be 5-10x that. And even if I'd be OK with the cost, my design needs to be very compact (so I don't have the PCB space for it).
That's why I'm trying to find a DAC that can deal with the CM108B hopefully give me better and louder audio.
That's why I'm trying to find a DAC that can deal with the CM108B hopefully give me better and louder audio.
CM108B will guarantee non optimal results and a device that just works. Isosynchronous USB... 16 bit maximum....so no high res....
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Right. However the TI DACs I was originally considering contain everything needed (charge pump, opamps) to get out 2V Vrms without additional parts. Not saying this is a must, but nice when you're working with space constraints.
16bit/48khz is what I'm aiming or, so that's perfect. If you have a suggestion for a non XMOS, low parts count asynchronous solution, I'd be happy to hear about it.
Which TI DAC did you consider ? The PCM5102a should support 256fs. Or you could run it in 3 wires mode.