Dear Craig:

You're absolutely right! Unfortunately, there's no such thing as a free lunch! True 20 bit and 24 bit recording requires more bandwidth than one track of an ADAT can handle, except for the newer model 20-bit ADATs (ed note...this added post 3 Jan 1997). It is necessary to use a multiplexer (such as the Rane Pacrat or the Prism model 2024T) and then you lose an additional track. In other words, the 8-track 16-bit ADAT becomes a 6-track 20 bit recorder! Just because Alesis says it uses 20 bit A/D converters doesn't mean that it stores 20 bit information. (Actually I thought they advertised 18 bit, but we'll leave that for the moment).

Using a 20-bit A/D without proper dithering to 16 bit can actually be worse than using the old 16 bit A/Ds in the previous version of ADAT! Let's hope that Alesis properly dithers the 20-bit A/Ds before storing on the 16-bit track. This will transfer some (but not all) of the 20-bit information to the 16-bit medium. So, where do we go from here? Well, firstly, I've made many excellent CD masters from material that was recorded on an ADAT.

You also should consider mixing down to a high-quality analog medium (such as 1/2" 30 IPS) because mixing down to DAT just reduces the stereo image, depth, and resolution even more. But if for economic or other reasons, a DAT is all you have, once again, I have made many excellent CD masters from DATs that were sent to me that had been mixed down from ADAT.

It's all relative. If you want the best, then don't cut any corners. I also often use some of my proprietary stereoization and other "tricks" to try and restore the lost dynamics, space, ambience and depth that often results from mixing to 16 bit from 16 bit, and the end result can be very beautiful and satisfying. Hope this all helps....

Best wishes,

Bob Katz, President