Chinese DA converter

[Roeland_R]

Hi folks,

I bought a cheap DA converter to connect my tv with toslink output to a 25 year old marantz receiver. It's a cheap chinese converter but it should do it's work. After connecting sound seems to be ok, but when watching a movie with much dynamic it sounds sometimes disturbed. I tried also another Technics receiver, same result. Perhaps I can change the output level of this converter, so I am looking for a schematic of it. Does anybody have the schematic already? As you can see on the pictures solderings are not very good. I am wondering if the 344C 1325 is the amplifier. Google doesn't help me here. I did find a pdf of the cirrus.

[wraper]

Q1 and Q2 connected directly to the RCA connectors seem like a strange schematic decision. IMO the distortion lies somewhere there. EDIT: probably they are for muting.

[wraper]

By the looks of it, there is no proper output filter for CS4344 DAC. https://www.cirrus.com/en/pubs/proDatasheet/CS4344-45-48_F2.pdf

[Roeland_R]

By the looks of it, there is no proper output filter for CS4344 DAC. https://www.cirrus.com/en/pubs/proDatasheet/CS4344-45-48_F2.pdf

Thanks for your help. I will try to draw the schematic in kicad. Also thinking of ordering an ad converter to connect to my function generator to check the signals of the da converter. TV doesn't fit on my workbench [emoji4]