Yes, it does work in original OBS 64 bit. Here is a manual log.
16:31:27: OBS 0.8.3 (64bit, windows)
16:31:27: CPU Name: Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz
16:31:27: CPU Speed: 3492MHz
16:31:27: Physical Cores: 4, Logical Cores: 8
16:31:27: Physical Memory: 8079MB Total, 5555MB Free
16:31:27: Windows Version: 6.2 Build 9200
16:31:27: audio settings reset:
samples per sec: 44100
speakers: 2
buffering (ms): 1000
16:31:27: ---------------------------------
16:31:27: Initializing D3D11..
16:31:27: Available Video Adapters:
16:31:27: Adapter 0: AMD Radeon R9 200 Series
16:31:27: Adapter 1: Intel(R) HD Graphics 4600
16:31:27: Loading up D3D11 on adapter AMD Radeon R9 200 Series (0)
16:31:27: D3D11 loaded sucessfully, feature level used: 45056
16:31:28: video settings reset:
base resolution: 1920x1080
output resolution: 1280x720
fps: 60/1
16:31:28: output 'adv_stream' (rtmp_output) created
16:31:28: output 'adv_file_output' (flv_output) created
16:31:28: encoder 'streaming_h264' (obs_x264) created
16:31:28: encoder 'adv_aac0' (ffmpeg_aac) created
16:31:28: encoder 'adv_aac1' (ffmpeg_aac) created
16:31:28: encoder 'adv_aac2' (ffmpeg_aac) created
16:31:28: encoder 'adv_aac3' (ffmpeg_aac) created
16:31:28: service 'default_service' (rtmp_common) created
16:31:28: WASAPI: Device 'Speakers (Realtek High Definition Audio)' initialized
16:31:28: source 'Desktop Audio' (wasapi_output_capture) created
16:31:28: WASAPI: Device 'Microphone (Blue Snowball)' initialized
16:31:28: source 'Mic/Aux' (wasapi_input_capture) created
16:31:28: source 'Monitor 1' (scene) created
16:31:28: source 'Random Game' (scene) created
16:31:28: source 'Monitor 2' (scene) created
16:31:28: source 'Monitor Capture 2' (monitor_capture) created
16:31:28: source 'Monitor Capture' (monitor_capture) created
16:31:28: source 'Game Capture' (game_capture) created
16:31:30: Update check: latest version is: 0.4.2
16:31:39: source 'Video Capture Device' (dshow_input) created