Using an Analog to Firewire converter, the FS4 Pro does not recognize the devices firewire input. Why?
Theoretically, if a converter provides a complete firewire video signal to the FS-4, then the device will work and the FS-4 will encode the incoming video signal. However, we tested both the Canopus ADVC55, and ADVC300 converters with our FS4, and for some reason they did not give us a DV signal that we could encode. We have not tested other A/D converters, so we cannot recommend a particular unit. However the FS4 works with almost all DV IEEE1394 25Mbps Firewire camera outputs, and if an A/D converter puts out a signal exactly like the cameras do, then it should work. If your FS-4 can record from a DV camera input, then the FS-4 is working correctly.
