Welcome to my website for audio enthusiasts and professionals alike. My name is Bob Cordell and I hope you will enjoy the contents here. I am both an engineer and a DIY hobbyist, and I love to mix the two.
The VinylTrak Phono Preamp
The VinylTrak phono preamp is a high-performance preamp for moving magnet (MM) and moving coil (MC) cartridges which I describe in a new article in Volume 4 of Linear Audio. The design includes an optional implementation of RIAA equalization that dispenses with the conventional R-C cartridge loading adjustments and the high-frequency electrical resonance with which they are associated. Click on the "Preamplifiers" tab for more information.
What's on this Site
Here you'll find information on audio electronics design and loudspeaker design, with several examples of each described. Within audio electronics, most of the material is devoted to power amplifiers and the design of audio test instruments, a good example being a DIY THD analyzer. The loudspeaker area includes descriptions of four loudspeakers, including an active 3.5-way mini-tower and a subwoofer. Most of the speaker designs use first-order transient accurate crossovers. The loudspeaker section also includes a description of EQSS™, a patented low frequency loudspeaker system technique that combines the best features of sealed systems and vented systems. Finally, over the years I've published a number of papers on audio, and PDF's of those are also available here.