Download ASIO proxy, latest version from Soundforge from this link. ( I am not sure if you need to have foobar installed first, you may or may not.)
http://sourceforge.net/projects/sacddecoder/files/foo_dsd_asio/
Install ASIO proxy on computer.
In Jriver, under AUDIO DEVICES, you will have an option for
foo_dsd_asio. Choose this as your driver.
Then, click on DEVICE SETTINGS. Then OPEN DRIVER CONTROL PANEL.
Under this, select your ACTUAL asio driver, if your device has one. If not, you will need ASIO4ALL.
Select DoP or Native for the type of DSD transmission protocol your DAC needs. There are also options for ExD and DCS(***See note at end of post****)
Be sure and DE-SELECT DoP as transmission format anywhere else, EXCEPT for the Asio Proxy options.
Then you can play with various types of SDM modulation, data rates etc. I tend to stay away from SDM A and C, as I can still hear some low level quantization noise in the playback! If I use 32fp (floating point) mode, though, the noise goes away, making me wonder if it is an issue with my computer not having enough horsepower to do the computations in integer mode. SDM B is VERY syrupy and lush, almost synthetic. I personally find SDM D to be the best overall. But experiment for yourself! It is fun!
****** Note that if your DAC supports and you choose Asio Native mode, asio native does NOT support 'illegal' data rates with DSD, So you are stuck with 2.8mhz, 5.6mhz, etc. Which means you will NOT be able to use any PCM rates that are a multiple of 48khz.
44.1, 88.2, 176.4, 352.8 work perfectly. 48,96,192,384 don't. To use those rates, you must choose DoP as your transmission format. But if you choose DoP, note you may lose the ability to upsample to DSD256, depending on your DAC.
It may be a little more trouble, but the results are worth it, in my opinion.