Taobao has a TDA1387 DAC (apparently)

Its rather difficult to work out whether there's a line-level output here or if the phono sockets are inputs to the LM1875 amps. The TDA1387 is a plug-in module for the USB-input DAC section which might feed only the amps. Anyone who's good at reading Chinese, please contribute in the comments

https://item.taobao.com/item.htm?spm=...8-3f2abc0f8bd9

Update - seems one particular vendor has quite a range of TDA1387 DACs now, all very affordable. The cheapest is this one (48rmb kit, 88rmb built in my limited understanding) - https://item.taobao.com/item.htm?spm=2013.1.20141002.7.yoDoCx&scm=1007.100 09.2083.i41769520252&id=41937738376&pvid=402c7a10-8221-4bca-82c0-99c1c511877f.
This one has 8 chips, I guess its a tribute DAC to the DAC-AH - https://item.taobao.com/item.htm?spm=...cket=17#detail