Prototype Power Amplifier

posted in: Audio Projects | 0

This is the working Prototype Power Amplifier I built around the LM3886T Power Amplifier IC. This unit was capable of approximately 85W RMS with a peak power output over 100W! This was the first amplifier I built that was over 50W as well as the first time I used this particular audio amplifier IC. This prototype would lead to several more refined versions that eventually became the amplifier I used for my DJ business. Read More

Prototype Audio Controller Power Supply

posted in: Audio Projects | 0

For my next project I broke things up into stages. The first step was to build the power supply for the audio controller section of my next amplifier. This is a 3-way power supply for that audio controller. The various circuits within the controller required 5VDC, 12VDC and -12VDC. This supply was designed to handle all of those needs. It used 2 transformers and three linear voltage regulators with heat sinks. Read More

Prototype Audio Level Meters

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These were my own design in audio level meters. This prototype was built to test in my next prototype audio controller. This design uses the LM3916N Dot/Bar display driver chip, and measures line-level audio signals. I got the 10-segment LED bar graph displays from Radio Shack. These work GREAT on line-level audio signals and are very fluid and responsive, allowing both dot and bar modes. Read More

Prototype Multimedia Amplifier

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As computer audio devices got better I felt a need for a better amplifier for my PC with more inputs so I could still have my SNES and Genesis connected. I also wanted to be able to see the level of the audio signal. This prototype had electronic input selection via four push-button switches on the front wired through logic into a special IC, the National Semiconductor LM1037N stereo audio switcher. The output of this amplifier used the LM2879 Dual 8-Watt amplifier IC, also by National Semiconductor. Read More

Production SNES / PC Amplifier

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This was an 8-Watt/channel version of the prototype. It used two LM383 Amplifiers. This final version also had an input selector for switching between your SNES and/or Sega Genesis, plus a better case with venting. This unit is still in use today by some old friends, although a couple say the volume control is a little crackly when adjusting it. I sold many of these to hardcore console and PC gamers back in the day. Read More

Prototype SNES / PC Amplifier

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This was a 2-Watt/channel audio amplifier designed for Super Nintendo or computer sound cards. This prototype used an integrated amp IC, volume control, power switch, power light, etc. The power supply was a surplus wall transformer, rated 15VDC @ 1000mA. This unit is still in use today by an old friend in NY. This project was a good example of what could be built using some spare parts found in my myriad of parts cabinets and drawers. Read More

Z80 Control Board

posted in: Z80 Projects | 0

Through the late 80s and early 90s the Zilog Z80 was my favorite CPU to work with. I loved the architecture, instruction set, capabilities and vast array of support chips available. I started designing commercial Z80 boards around 1992 and the early designs were built on perf-board and wire-wrapped. This article discusses a couple of early boards I made, the design, the development tools I used and even some example code. Read More

QuickBASIC Applications

posted in: PC Applications | 0

A collection of applications I wrote in both QuickBASIC 4.5 and PDS 7.0 that ran on a DOS PC with CGA/EGA/VGA graphics. These applications are very old and do not run on modern 64-bit architecture. You made need to use a special emulator to run them, unless you have an old DOS-based PC. You can click the title of each application to download it as a ZIP archive. Read More

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