Valve amplifiers

Why do valve amps sound "better"? Distortion, its that simple.  In fact you can design valve amps and remove most of the distortion they tend to have and they then loose all of that warmth that audiophiles claim makes them better.  However the truth of it is that the warmth is simply a distortion imperfection in […]

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Balanced Audio Connections

Creating A Balanced Line Output From an unbalanced¬†line level signal Converting Balanced Line Level to Un-Balanced NOTE: The 22K resistors used here work great, but 22K can cause noise to be picked up from close digital tracks (e.g. 3.3V clock signals). We discovered just such a problem on a digital PCB causing pickup to occur […]

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Audio Beat Detect

A working audio beat detect circuit for a microcontroller using a microphone input This circuit uses a digital pot to allow the microcontoller to automatically adjust the gain of the circuit to suit the ambient audio volume, but you could replace this with a standard pot if this isn't needed.  The low pass filter is […]

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Solving Audio Hum Problems

Noise is the bane of audio design! Here are some of our tips to help solve hum problems in a PCB design. Can you provide a connection from audio ground to mains earth?¬† This can really help reduce hum and get rid of problems of moving your hand near a circuit and introducing mains born […]

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Audio Circuit and PCB Design Tips

Designing audio circuits remains a challenge and aspects of it are still often considered a bit of a black art.  Even the best designers often have to build more than 1 PCB to produce a high quality noise free design.  Below are some tips from our experiences… Power Supplies & Grounds Transformers are great for […]

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