Fast Transimpedance aka Voltage Amplifier Stages for Audio Power Amplifiers
in Power amplifiers, Technical
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.
RIAA Equalizer Amplifier Design
in Technical, Vinyl preamps
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, […]
Ground Loops
in Technical
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 […]
MC Head Amp Circuit Compendium
in Technical, Vinyl preamps
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 […]
How to wire-up a Dual Mono Bloc Amplifier
in Power amplifiers, Technical
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 […]
Noise in Electronic Circuits
in Technical
I’ve gathered a few articles here on noise as a go-to reference for anyone interested in the subject. These articles really focus on Johnson noise and not induced noise which is discussed in depth in the ‘Ground Loops’ post elsewhere on this site. I will update this post with new material as and when it […]