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 phenomenon all bipolar transistors suffer from.

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RIAA Equalizer Amplifier Design

This article explores the fundamental’s of phono amplifier design,  culminating in a few practical designs. Special emphasis is placed on overload margins (critical if you want good sonics from your EQ amp), driving the EQ network adequately and noise. RIAA Equalization Amplifiers V2.0 Below is the RIAA Calculator Excel spread sheet.  Please read the article above, […]

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Ground Loops

Updated with new material 7th January 2019 This set of c. 70 slides is the culmination of my experience over a period of about 25 years building numerous power amplifiers and preamplifiers. I first started out in audio around 1975 or 76 as a teenager. Some of my creations were reasonably quiet – through pure […]

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MC Head Amp Circuit Compendium

Here is the new updated moving coil head amp designs compendium – updated 31 July 2019. The first file is a PDF compendium of about 28 different circuits with noise, distortion and current consumption details. All the LTspice sim files are zipped in the second file. What is immediately apparent from this is that having […]

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How to wire-up a Dual Mono Bloc Amplifier

A few people have asked about wiring up a dual mono amp aka dual mono bloc. In a dual mono bloc there are separate power supplies and lots of opportunity for cross channel ground loops and ordinary ‘classic’ ground loops as well. This wiring scheme addresses the situation were unbalanced connections between the source equipment […]

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