Amplifier History: The JBL SA-600
The beautifully styled JBL SA-600 amplifier was launched by the James B. Lansing company in 1966, and Bart Locanthi (the designer) wrote the technical article linked to at the bottom of this write-up in January 1967. I’ve included this in…
Feedback: A Short History
“Why, sometimes I’ve believed as many as six impossible things before breakfast.” ― Lewis Carroll, Alice in Wonderland A Future Without Feedback by Martin Colloms There is no mysticism in amplifier design, just serious science. —Andrey A. Danilov Introduction You…
The Tale of Two Recordings
I thought I’d share my thoughts with you on the sound of two LP’s I recently acquired. Many of you will have heard of the term ‘sound wars’ which has been coined to describe the relentless increase in the use…
JLH 10 Watt Class A Amplifier
This is a copy of the original John Linsley-Hood article that appeared in Wireless World in 1969. This design, almost 50 years old, is still built in its hundreds all over the world. A quick root around on the web…
Class A Buffering the Correct Way
Here’s a simple way to force an opamp output stage to run in class A when used with a discrete buffer output stage – it takes just 1 resistor to provide a near constant current source load. Operating the opamp…
