After a Reaper session, my Windows audio becomes pitched down as if it is being played at a different bitrate. Running Reaper 3.71 under Windows7x64 using a Tascam US-122mkII interface.
--------------------- 2001 Saphire Black M Coupe IE Subframe Bushings, UUC TME Reds, Goodridge SS Brake lines, UUC SS Clutch line, Sport Mode, Strong Strut STB, Toyo T1-R (street) 235/255 Toyo RA-1 (track) 255^2 , Eisenman 76mm Sport Exhaust, TCK D/A 450/500#,TCK CP, 3.46
How would I go about checking that? I suspect it is a sample rate issue. Windows plays audio at a certain sample rate, Reaper switches to a different sample rate, and then when I close Reaper, the sample rate isn't "released" by Reaper and Windows is forced to conform to the Reaper sample rate, messing up the sound in Windows. That's my guess.
To be honest, it's been so long since I've dealt with something like this that I couldn't really guide you through the steps needed to fix this.. but until someone who knows the correct solution chimes in, you should be able to reset the sample rate in your ASIO driver after you close Reaper (probably to 96khz).
Never heard of this before (that Reaper locks the samplerate of the device). Have you tried to disable (or enable, as the case might be) "Request sample rate" in Preferences > Device?