Sending 32 bit files for Cutting RE Dither

Robert Katz

Chas wrote:

HI Bob, I know you’ll have the answer to this or refer me to the right part of the book. It’s not clear to me what happenes if I send a 32 bit file somewhere to have a lacquer cut.  Since  we know there is no 32 bit playback, only 24 bit, the question is. Do A to D converters add dither to 32 bit file automatically before converting to 24 bit for playback.

Dear Chas:

A to D converters do not receive files. They receive analog input. So your question is not relevant to A to D. D to A converters do not automatically add dither and you should not feed a 32 bit float file directly to a D to A converter as it will truncate some low level information. That said, the difference is quite subtle. But I do recommend you dither the 32 bit float file to 24 bits prior to sending out to anyone, including cutting. And examine your levels very carefully!

And if they do not does that mean i should only send 24 bit dithered files to the cutting master so he doesn’t cut from an undithered 32 to 24 D to A conversion?

Yes, absolutely!

Hope this helps,

Bob