I just learned that the stalwart R2R-11 by Kingwa and his crew at Audio-gd has been DISCONTINUED due to cost and availability of parts:

https://www.hear.audio/2021/06/19/the-end-of-an-era-for-audio-gd-r2r-11/

This combo unit is an incredible bargain and a great entry in the world of R2R and Audio-gd. I've moved on to separates everywhere. I have the incredible Audio-gd R2R-1 in my bedroom speaker system and the R2R-11 is the reason I tried the upgrade. Please enjoy this DAC/Amp as much as I have.