Is there a way to get the SMSL to do the upsampling instead of Windows drivers?
Let's keep this as simple as possible. You
must use audio applications that are capable of WASAPI or ASIO operation, as only these modes offer the means of bypassing Windows unwanted SRC. I suggest that beginners use WASAPI as ASIO often adds an extra control interface that can further conflate the situation and confuse the unwary user. There is
no sonic difference between the two in standard domestic use.
The following relates to Windows 7. Later versions follow the same general pattern but differ in detail.
Having successfully installed the Thesycon driver, go to Control Panel / Sound / Playback and therein you should find an entry for your DAC. Select it and then press Properties. In the box that now appears, pick the General tab. Herein there will be a further properties button – press it. Select the driver tab and check that the signer is Thesycon. This ensures that you are really using the driver that you need. When satisfied, press Cancel. Go to the Advanced tab of the box now exposed and select the two check boxes under Exclusive Mode. Do not worry about the audio properties drop down as selecting exclusive mode overrides this and gives total control to your audio application when using WASAPI. You can, at this point, press Test
but watch the volume! If your DAC plays the test sound, it proves that all is going according to plan. The test sound sent to the DAC will be at the sample rate specified in the drop down. You might care to check that the DAC display agrees with the value set. If not, something is wrong. If all appears well, OK, OK to get yourself back to the desktop.
Open your desired audio application and ensure that it is set to use the WASAPI interface. If your application does not support WASAPI or ASIO, delete it and find something else. That's it really.
But one more thing worthy of note, having set-up audio on dozens of Windows machines. Unless you are really sure of what you are doing, make the default audio device something other than the DAC connected to your prize speakers. There are quite a few reasons for me suggesting this, but they are all based on the premise that it's too easy for random bits of software to access the default audio and send something at an unhealthily high level to your speakers when you least expect it!