RIAA Equalizer Amplifier Design
This article explores the intracacies 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…
Hifisonix kx-Amplifier
The Hifisonix kx-Amplifier is a 28 Watt class A DIY Current Feedback (CFA) power amplifier featuring low distortion, wide bandwidth and fast rise/fall times. It can be operated either in pure class A mode, or in class AAB mode with…
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…
An Accurate Inverse RIAA Network
The diagram above summarizes the interaction of the cutting head response (purple) and the playback EQ (red) which produces the final flat response (green). Note that the cutting head and the phono pickup (cartridge) are velocity transducers and therefore the…
Ovation Symphony Line Preamplifier
I designed and built this preamplifier while living in Taiwan a few years ago. The ‘Ovation Symphony’ features Baxandall tone controls, up to 7 inputs, a class A 2 W headphone amplifier and a Goldpoint 24 position attenuator. The write-up…
