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I previously worked on Virtual Reality and other hardware at Valve.  I currently work at Google[x].

Prior to starting at Valve, I built computer peripherals such as keyboards, mice, and joysticks that were designed to be used inside MRI machines.  My company, Mag Design and Engineering, sold these devices directly to researchers at academic institutions who used them to publish scientific papers in peer-reviewed journals.

After work, I spend time on many different types of projects that usually involve circuit design, machining, material selection, and general fabrication/hacking.  My favorite place to be is my home workshop.

ben dot krasnow at gmail




Wednesday, May 28, 2008

Eliminating sound problems (crackling, popping, stuttering) on a Dell Vostro 1700

I really like the Vostro 1700, but one of the few problematic areas is the sound system. When the computer is completely idle -- no programs running, no downloading, no nothing -- the sound playback from MP3's, WAV's, even CD's has lots of crackling and popping in it. The problem is pretty noticeable since the audio interruptions occur once or twice a minute.

After some web searching, I found that some people have cured similar sound problems on other Dell notebooks by disabling the 802.11a band of the wireless network card. This band is not used for b or g communication, and so probably will not affect wireless communication with modern routers. I disabled the a band (control panel -> system -> device manager -> network card -> options) and it seems to have cured the sound problems completely. I'm guessing the 802.11a frequency domain interfered with the Sigmatel audio chip. Lousy RFI/EMI protection?

Friday, May 9, 2008

Enabling "stereo mix" recording on a Vostro 1700 w/ Vista

It seems that either Dell or Dell's soundcard manufacturer decided that customers should no longer have the ability to record audio from the web. In the past, I could use a program like Audacity to record Youtube audio tracks, iTunes tracks, sound effects from games, etc. After buying my new Vostro 1700 laptop from Dell, I noticed the "stereo mix" or "wave out" option is no longer available.

After a few hours of web searching, I found a solution. Download the XP driver for the Vostro's SigmaTel soundcard from here:


The driver number is R171789. Run the .exe and upack the files. Cancel the driver installation, which starts automatically after unpacking. Browse to the unpacked files, and open the properties dialog for setup.exe. Choose it to run in XP SP2 compatibility mode, and to run as administrator. Run setup -- the driver should install without any errors or warnings.

Now, open the control panel, open the "sound" dialog, and select the recording tab. Right-click in the empty space and choose to view both disabled and disconnected devices. There should now be a stereo mix item -- right click on it and enable it.