Hi,
One of the things I like about the C64 is the SID chip. I use the CH2 in cartridge mode and wonder: would it be possible to insert the C64's Sid sound in the CH2 so it can be mixed with the headphone exit? I am thinking about a riser under the SID that exports the audio and somehow inserts that in to the CH2?
If the C64's cartridge slot doesn't have an audio, then perhaps a small audio input connector for stereo input? I have a SIDFX installed that does stereo sound and optimally that stereo sound can be passed through.
About the built-in SID player: does that determine which SID is on board or not? I tried to play some stereo songs on my dual 8580's and the SID player reports 1 SID 6581.