There are situations where a low output impedance to A headphones is required. This article discusses three different versions of headphone amps to fit your particular application: a stereo amp powered by the power line; a battery-operated mono amp for a crystal set; and a battery-operated amp for a ceramic cartridge.
Over the years with different companies I’ve worked for, I always had access to high-end audio THD (Total Harmonic Distortion) analyzers. I found these very useful for design work, debugging, and repair of audio equipment. My present company has no need for them and consequently they aren’t included in their armory of test equipment. Oftentimes, I have need for one but could never afford to own one — not even a used one. I thought this would be a worthwhile project, so this article describes how to construct one.
The MIDI Replay stomp box is a powerful configuration and recording device for keyboard players, based on the wonderful MIDI protocol: the standard musical language of over 30 years.
This article explores the design challenges of this real-time system and covers topics such as task scheduling, buffers, parallel computing, dynamic memory management, response time analysis and menu system design.
When my wife and I moved into our current home a few years back, it didn’t have a doorbell. We live on a quiet cul-de-sac, so it really wasn’t a problem as we had few callers. After a while, I installed a wireless doorbell that lasted about three years. Recently, after writing the series of articles on “A Digital Analog — When a PIC Can Replace a 555,” I decided to make one using a PIC.
The Macchiato is a build-it-yourself/do-it-yourself (DIY) miniature eight-bit, polyphonic, digital music synthesizer kit. Derived squarely from the circuitry roots that are deeply entrenched in the pioneering work of American synthesizer maestro, John Simonton of PAiA fame and the legendary analog 1980s Pro-One synthesizer from Sequential Circuits, this offering from Zeppelin Design Labs is much more than just a kit.
Since the time when solid-state amplifiers were first designed using early power transistors, a great deal has been done to improve them. This article will show you how to construct an inexpensive amplifier; the power supply described here will run two channels.