USB audio interface

I have been looking for a USB audio codec for my next project. It is a class-A mic pre to be used with computer. The idea is to replace my old Revox PR99 in not so critical recordings.

Texas PCM2900 looks quite handy. Only a few passive components are needed to make it a bridge between USB and analog audio. And it works in both directions (play and record, that allows to add headphone monitoring easily). Specs could be better and it is only 16 bits.

All others chips that i have found need a microprocessor or at least codec and converters are separete chips. Is it really possible that Texas has the only easy to use two-directional codec.

There are number of "USB soundcards" available advertised as 20 to even 24 bits. They are small and cheap, so the circuit inside can't be very complex. Has anyone looked inside or made own designs.

[quote author="audiox"]Specs could be better and it is only 16 bits.[/quote]
The plug 'n' play, works-with-Windows-and-Mac-and-Linux USB audio standard (forgot the name right now) is only specced up to 16/44k1 (some support 16/48k). All the others (M-Audio, Edirol etc) have a USB microcontroller with custom firmware. This takes quite a bit of work to DIY, and I'm not aware of anyone who's done it.

If 16/44k1 is okay but you'd like better specs have a look at the PCM2906. It has S/PDIF I/O, so you can use your favourite ADC.

JDB.

I don't know what chipset is in it but the M-Audio Sonica Theatre is a great sounding USB audio interface. You might check into whatever chipset is used in it.