Richard Lee’s Ultra-Low Noise MC Head Amp
This design was a development of Marshall Leach’s MC head-amp from the 1970’s and to my knowledge, Richard Lee’s implementation presented here has not been bested in terms of noise – about 280pV/rt Hz in a well implemented exemplar. Importantly, it requires only about 12mA current in the +-15V rail powered version, and about a […]
Hifisonix ‘Symphony’ Line Preamplifier
I designed and built this preamplifier while living in Taiwan a few years ago. The Symphony preamp features Baxandall tone controls, up to 7 inputs, a class A 2 W headphone amplifier and a Goldpoint 24 position attenuator. The write-up describes the design process and choices in some detail and my listening impressions: Part 1 […]
OPEX-1: A Discrete OPAMP for Audio
This design showcases a discrete opamp for audio applications. It features very low noise, low distortion and a class A output stage that will deliver 1ppm distortion into a 600 Ohm load at 12 V peak. OPEX-1-Discrete-Opamp
Opamp Noise Visualizer
This Excel spread sheet tool was developed from one by Steve Hagman (www.AnalogHome.com) and allows en and ien data for up to 7 opamps to be compared. When using the tool, make sure you enter comparable data – so for example, always use the same frequency to make the comparison. I normally use 1 kHz […]
Ovation SCA-1: A high performance fully balanced line pre-amplifier
Originally published in 2010 Here is the result of my investigation in to a fully balanced high performance, low distortion line pre-amp, the ‘Ovation’ Stereo Control Amplifier One’. I drew some inspiration for this project after reading about the TEAC Esoteric line preamp, which is also based on the TI PGA2320, and received rave reviews […]