Dolby was just pre-emphasis of the higher frequencies before they were written to the tape. It will sound the same with 8 bits. 8bit quantization will give you

Dolby was just pre-emphasis of the higher frequencies before they were written to the tape. It will sound the same with 8 bits. 8bit quantization will give you 48dB dynamic range (best case). Call it 36dB practical, around the same as an average cassette tape.