The Software Radio Laboratory QS1R is a high performance direct sampling software defined radio (SDR) that covers 10 kHz to 62.5 MHz. SDRMAXV software is provided by the manufacturer via electronic download. Up to date source code access is available to users who sign a NDA. SDRMAXV is implemented as a client-server application, with a non-GUI server and a full-featured GUI client. It builds and runs well under Linux, MacOS, and Microsoft Windows. There is also now a simpler SDRMAX_Remote_Basic client that foregoes the spectrum analyzer and waterfall displays in return for much lower CPU usage. It is one sweet receiver in my humble opinion.
QS1R Front Panel
QS1R Rear Panel
SDRMax IV Graphical User Interface
SDRMAX_Remote_Basic under Fedora Core
Third party software, like CW Skimmer and Skimmer Server, can also load code into the QS1R FPGA for execution. Skimmer Server, for example, can run up to 7 independent receiver chains simultaneously within the QS1R. The QS1R frequency can also be controlled via the CW Skimmer telnet interface. Guenael Jouchet's qs1r-multirelay software loads similar code into the FPGA to allow recording 7 audio channels.
I route the QS1R DAC output via a Pyle PHA-15 to a Falcon F251A-0301 Audio Distribution Amplifier and then to my choice of classic Hammarlund, Hallicrafters, and other boatanchor radio speakers. This doesn't affect potential use of the audio via the computer sound card, since that path goes through the USB cable. The QS1R sounds as good or better than my other communications receivers.