Jason Neal's DIY Audio and Electronics Page

  Microphone Preamplifier
A battery-powered microphone preamplifier and microphone wand for acoustic tests and recording.  This project is the result of a collaboration with Eric Wallin to provide a low-cost, high quality kit for do-it-yourself audio enthusiasts.  The preamplifier features 20dB of switchable gain and a clipping indicator, and microphones are available in calibrated and raw form.  Inside you'll find the circuit description, construction details, technical performance analysis, pictures of the completed kit, and information on obtaining a non-profit kit based on the design.
 
Preamp kits are no longer available.  As much as I hated to do it, I was unable to devote the time necessary to support the project.  This page is here for reference purposes.  I will return to loudspeakers again someday.

  Dual Polarity Power Supply
Two versions of a dual polarity power supply with printed circuit board artwork.  The supplies are built around the popular LM317 & 337 complementary voltage regulators which offer very high ripple rejection as well as short-circuit and thermal protection.  The first version is a compact fixed-voltage supply for situations when you need a high-quality regulated supply in tight quarters, such as hi-fi active crossovers.  The second version is a larger variable supply that uses more extensive heatsinking, and laid out in such a way that it may be mounted to a heavy duty chassis heatsink for even greater power dissipation.
  Wire Gauge Spreadsheet  (Corel Quattro Pro format) (Microsoft Excel format)  Right-click and choose 'Save Link As' or 'Save Target As'
This handy little spreadsheet will calculate various parameters associated with copper wire, among them:
 My Car - 2003 Hyundai Tiburon GT V6
  Miscellaneous Photos
  Click here for a brief overview of MCM's aluminum cone subwoofers which were liquidated near the end of 1999.

Revised:  October 11, 2003
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