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. […]
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 […]
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 […]
Noise in Electronic Circuits
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 […]
Ovation 250 Power Amplifier
The Ovation 250: A 250W per Channel Audio Power Amplifer (updated 1st June 2013) This amplifier was built in 2005/2006 and this write-up originally published in 2009. Introduction Diy Audio is a wonderful activity:- if you cannot afford a $10 000 power amp, you can always build one that comes pretty damn close in terms of sonics […]
The Monolithic Op-Amp: A Tutorial Study
This was an invited paper at the ISSCC in 1974 by James Solomon, who at the time worked for National Semiconductor (acquired in 2011 by TI). Those were heady days in semiconductors, with major process and circuit design breakthroughs taking place at breakneck speed. The general purpose microprocessors’ pivotal role in powering the Apple II […]