About Me

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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




Thursday, July 24, 2008

Bathroom vanity cabinet

Here are some pictures of a bathroom vanity cabinet that I designed and built for a friend.

Adding pre-amplifier outputs to an Onkyo Receiver

I bought an Onkyo TX-SR505 receiver and really like it. It has a lot of good features, will drive 4 ohm speakers (despite what the manual says), and accepts a variety of signal inputs. However, there is one missing feature that I would really like to have: pre-amplifier outputs. This would allow the use of an external amplifier and additional signal-chain devices (such as a graphic equalizer). I feel strongly that room compensation with a graphic EQ is important, but that is a topic for another post.

I opened the cover on the TX SR505, and eventually found a convenient place to tap into the pre-amp signals. I used some short lengths of shielded cable to connect three newly-added RCA jacks to three points on the main audio board. Note that the cable shield is only connected to the metal receiver case at one end. I think the photos will explain everything better than I could in words, so take a look.