For those portable radio / CD player stereo system / boombox, is the internal digital or analog out?

[Happy Hopping]

For a home system, say you have a typical DVD/CD player that c/w optical out or Digital Co-ax out. Normally that goes to a Pre-Amp, then a power amp., then the speaker

By comparison, for those portable stereo system / boombox, from the CD player component goes to the integrated amp. portion of the box, is that digital out or analog out?