I want to play around a bit with my Commodore 128 VDC chip. So I recently ordered a CGA2RGBv2 and it works fine when connected to a GBS-8200.
However, I have a Silicon Image Iscan scandoubler I'd rather use than the GBS. Problem is, the Iscan only has a YPbpr input. Is there an easy way to connect the CGA2RGB to an Ypbpr input?

Unfortunately there is no simple way to convert between the two. The results of the conversion equations can't be accurately represented with the simple 2 bit DAC in the CGA2RGB. Because of this a full analog solution similar to the GS2HD is required.
In addition a suitable composite sync mus be generated and mixed on the Y channel.