Issue with cdrom and Dac in a Box

[toolkit]

My Marantz CD63 has started skipping and so I've gone for plan B, cdrom drive with pradit_p's cdrom controller kit here and a DAC67 from Diykits in HK (Dac in a Box). It works OK with a Pioneer slot-load DVD drive although I have to load the CD twice to get it to read properly - the kit is not designed to work with DVD drives. So I have gone back to a pile of cdroms but I can't get anything out of most of the CD drives - or maybe a couple of seconds of the first track then silence. If I plug the cdrom and controller into a spare digital input on my home theatre system it's fine...so I asked diykits and got this reply - could anyone with more technical knowledge translate it a bit for me?

""The dac-67 is without mute.
when your CD-rom stand by ---there is no output or mute function at output stgae.
Then dac-67 is no loading and having noise.
Until you start to play ---dac-67 have loading again and no more noise .
That is the design of dac-67 and CD-rom -----no mute function and cost this .
Either one have this design will not happen like this !
That is why for Cd player use .""