Are you sure about that? My experience with the sound issue has been that the SGM's sound chip cannot output via the monitor cable, but it works fine via the regular RF output.
The sound output from the 7-pin DIN Auxillary Port on the Stand-Alone Adam Memory Console was improperly tapped by Coleco... the same way that early Composite A/V mods were improperly tapping the sound.
Due to this the Expansion Module #1, the Opcode SGM and the Juicebox Audio will all experience the same "low volume" output when using a Monitor Cable plugged into the Auxillary A/V Port. The RF A/V output will obviously not suffer from this problem.
The quick fix for this issue is to turn up the volume on your TV all the way to hear the audio output, but most will experience some to a lot of line noisebfrom the TV volume being turned up so high. The proper fix is to remove how Coleco made their hack for audio output and tap off of C88... once this is done, audio is as crystal clear with proper volume output just like a Yurkie Composite A/V modded ColecoVision.