It is a very good interface for driving PowerAmps from unsymm. Preamps / HandyOutputs by Jack. Check please the Photo, here you see how to increase Amplification. Adding a 33 kOhm resistor in parallel to Rx gives double output swing ! Check capacitor if you increase more.
There is another product in the picture, different design PCB, and not originnal IC, (there no original Analog Devices and Philips IC's)