Samplitude PROX4 + ASIO4ALL drivers will only connect to one sound device. I cannot record and playback at the same time. Windows 10.
With an ASIO audio interface you’re able to record and playback at the same time, even with ASIO4ALL, you just have to set the correct monitoring settings.
It’s correct that when using the ASIO4ALL driver you can only use ONE sound source/program/application at the same time. E.g. when Samplitude is opened you won’t be able to listen to a YT video. But that is not caused by Samplitude. Anyway it’s recommended to use an audio interface that uses its own generic driver.
Some users wrote that they installed the free demo of Fruity Loops that comes with an ASIO driver that seems to be able to use more than one sound device at a time. Maybe try the driver as an alternative.