I2S to AD1862

[batteryman]

I've just received a pair of these dual AD1862 (mono dac) kits from DIYINHK. (not with the Xmos board or dac chips). I was disappointed to find that they have not provided the correct capacitors for the dac's noise reduction feature and don't supply any documentation. There are 3 chips labelled DRC1 and DRC3 but I can't find out what they are and where the FIFO is. i was expecting better but they aren't an improvement on most Ebay sellers.

https://www.diyinhk.com/shop/audio-k...o-reclock.html

It seems to use AD's method (described on AN207) to convert I2S into the 3 wire PCM needed by the dac chips. (MSB first, left justfied, TWC) See image.

Their description is below and is slightly unusual in that both dacs receive left channel data which is transmitted first, then the left dac's clock is stopped so only the right one receives right channel data, then both dac's are latched at the same time. Reminds me of IanCanada's I2S to pcm board but for two's complement rather than offset binary.

I think the two of these boards will work with two TDA1541s - one board drives one dac with right & inverted right data, and the other drives the other dac with left & inverted left data. (with the TDA 1541s in TWC mode)

[rfbrw]

Originally Posted by batteryman

I think the two of these boards will work with two TDA1541s

The TDA1541 is 16bit and the AD1862 is 20bit .

[kazap]

Originally Posted by batteryman

I've just received a pair of these dual AD1862 (mono dac) kits from DIYINHK. .......

What do you think of the quality of the board?


Despite the lack of documentation is there enough info to complete the build or are you going to return it?

[batteryman]

Originally Posted by kazap

What do you think of the quality of the board?

Despite the lack of documentation is there enough info to complete the build or are you going to return it?

When I enquired they said all the info was on the webpage but there is no mention the I2S input must be 3.3v, which is a serious omission given that most older CD players with I2S use 5v supplies.

The 3.3v input does not seem to be needed unless you buy it with the XMos USB board but again, I have had to ask the question and am waiting for a reply.

The boards and smd soldering is fine. The silk screen includes the pin designations but you need to consult the datasheet for the correct capacitors (1 and 10 or 2.2 & 22uf Tantalum - 2 of each per board needed.)

No excuse for not providing some basic documentation though.

I will only return it if it doesn't work - I'll find out in a few days.

[batteryman]

Originally Posted by rfbrw

The TDA1541 is 16bit and the AD1862 is 20bit .

Yes but my source is CD so 16bit.

[kazap]

Originally Posted by batteryman

When I enquired they said all the info was on the webpage but there is no mention the I2S input must be 3.3v, which is a serious omission ......

That's good to know. Hopefully the poor documentation isn't insurmountable. I'm very interested to follow your build and what you think of the sound quality. Thanks.

[rfbrw]

Originally Posted by batteryman

Yes but my source is CD so 16bit.

There is a bit more to it than that.

[batteryman]

Originally Posted by kazap

That's good to know. Hopefully the poor documentation isn't insurmountable. I'm very interested to follow your build and what you think of the sound quality. Thanks.

I am now listening to the DIYHK AD1862 NOS dac and it sounds great although its a while since my TDA1541 dac has worked so nothing to compare directly.

The stopping of the left channel dac does happen so both dacs are latched simultaneously as stated on their webpage.

I am using a SRC4192EV sample rate converter set to 20bit output and its on board SPDIF input (CS8414) from a Marantx CD65.

I have tried various output settings with FS of 22, 24, 48k and 48k is marginally better (bck is ~3Mhz with 48K FS).

[batteryman]

A further improvement is heard when increasing FS to 96K (bck = ~6Mhz, and mck = 12.88MHz). That's as high as the SRC will go from its SPDIF input.

[kazap]

Originally Posted by batteryman

I am now listening to the DIYHK AD1862 NOS dac and it sounds great ...

Well done!



Are there any problems with the build that would trip up a beginner?



Its cool having the SRC that puts out 20 bits for the AD1862. But my source puts only puts out I2S at 24bits. I wonder if you can please see if that works?