PCM63 Adaptor Application Note:

On the top of the PCM63 Adaptor card, locate legend:  U2 PCM63

to the left of this legend, the first Pin corresponds to Pin1 of the original PCM63.

to the right of this legend, there is a  3-pin , identified as WORD.

The factory default setting is 20 bits(jumper away from the chip PCM1704)
It can only  be set to 24 bit if the incoming word is 24 bit.(jumper now closest to the chip PCM1704)
To comply with the configurations and parameters of the original PCM63, this should be set to 20 bit.
(setting to 24 bit would only result in noise)

Do not solder the adaptor card directly onto the board:
Use a 28-pin IC socket(available from Monarchy Audio) and insert
the adaptor carefully into the socket.  
Please note the pins are very small and if they break off from the adaptor card the whole card becomes useless.

Also because the card could be erroneously inserted causing
damage to the parts on board we cannot offer any free replacement.

Please note on the original PCM63, there is a stand-alone feedback resistor at Pins 9 and 10. This resistor is not provided in the adaptor and if necessary a 1.8K resistor can be soldered onto the card  if the overall circuit calls for it.(Refer to Monarchy’s Website
for a data sheet of both PCM63 and PCM1704).

Pease note Monarchy Audio now also supplies a lower cost version of the PCM63 adaptor card, made with two AD1860 in a Piggy Back configuration, factory trimmed with a 100K trimmer
for lowest distortion, for an 18-bit environment with excellent sound quality, at just
US$10.- each.
For details please contact Monarchy Audio’s  email: monarchy@earthlink.net