John John Ackermann N8UR wrote: > Rex said the following on 01/09/2009 06:37 AM: > > >> Maybe I lost track and missed something, but I don't think I ever saw >> more on the subject of specific high-end sound cards that might be >> useful for nutty measurements. >> >> I'd be interested to hear what any of the group has to share about >> relative merits of current sound cards that can be interfaced for >> measurements like what was being discussed in that earlier thread. (And >> some before and since.) >> >> From my own point of view, I'd most like to hear about any that are >> external -- connected by USB or 1394, rather than an internal card. This >> makes it more portable and easier to move between different PC's. >> > > [Shameless Plug] > > One very interesting possibility is the HPSDR (High Performance Software > Defined Radio) boards called Ozy and Janus. Together with a passive > backplane called Atlas, they provide an extremely high performance > ADC/DAC that supports sampling to 192k and output via USB. The system > was designed for use as the interface between a PC and an SDR and > special attention was paid to low noise and flat frequency response. I > am not certain, but I *think* that the inputs are DC coupled. > > Not according to the circuit schematic. The input coupling is 10uF + 10K with a corresponding low frequency 3dB cutoff of 1.6Hz. Default inputs are single ended, balanced inputs are accessible via a pair of headers. Input full scale is that of the AKM5394 ADC chip (1.7Vrms nominal). There is a small dc offset between the differential inputs to the AKM5394 to eliminate an idle tone related spurious output.
> The two boards, assembled and tested, run about $320, with a discount > for TAPR members. The backplane is a fairly simple kit (lots of > connector pins to solder, but not much complexity) that sells for $28, > also with a discount for TAPR members. Bare boards, but not kits, for > Ozy and Janus are also available for the adventurous. > > I'm not aware of anyone using this system for T&F work, but it has some > interesting possibilities. > > [/Shameless Plug] > > John > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > Bruce _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.