The ax-Amplifier has landed!

Part 1 of the ax-Amplifier will be published in the April issue of audioXpress out on 15th March, with Part 2 to follow in the May issue, out mid-April. You can order copies of audioXpress here audioXpress Magazine Subscription – CC-Webshop The ax-Amp is a topologically simple 60 W RMS per channel class A current […]

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Spin 2 of the nx2-Amplifier PCB . . .

In the last update on Feb 1st, I had just received the PCB back from the PCB house. Since this was my first design on KiCAD, I wasn’t expecting much, so it was as much a learning exercise as it was a first PCB spin. Well, half the silk screen was missing, some of the […]

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Using the QuantAsylum QA401 for accurate Audio Measurements

The QA 401 from QuantAsylum (superseded by a newer, improved QA 402 and now the QA403) has emerged as a popular, comprehensive audio test instrument in the DIY audio fraternity and the go to instrument in many cases for commercial production testing in the audio industry. It combines a first rate DAC and ADC with […]

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Building Quiet Audio Power Amplifiers Requires Best Wiring and Layout Practices

There is a misconception that noise pickup is reduced by placing the input RCA connectors (and similarly XLR input connectors in a fully balanced system) on opposite sides of the amplifier rear panel and then running short wires to the amplifier modules. This arrangement is the worst of all worlds. The internal loop areas available […]

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So Just How Quiet is Your Phono Stage?

You may be in for a surprise: actually not that quiet! The reason of course is that the cartridge inductance and resistance dominate the noise in any decent phono amp. To get the best in terms of noise performance, you really need to keep the input referred noise voltage and noise current to a minimum. […]

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Fast Transimpedance aka Voltage Amplifier Stages for Audio Power Amplifiers

Here is a quick look at some of the problems that can occur when the VAS (aka TIS) in an audio amplifier is driven into saturation without considering the effects of base charge storage – a phenomena all bipolar transistor suffer from.

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