Linear Systems Announces LSK489 Premier Performance JFET Re-Release

Linear Integrated Systems, the world class producer of ultra-low-noise JFETS and other small-signal discrete semiconductors, has announced the re-release of its LSK489 discrete component with specialized parameter grading. The LSK489 is one of the world's premier JFETs optimized for use in high-end sensor front-end amplification designs, and the re-release in 2022 introduces improved manufacturing consistency.

Linear Systems announced the re-release of the low-noise, low-cost LS844 series dual JFET with immediate large-scale availability and large-volume pricing. The re-released LS844 is the latest evolution of a classic dual JFET developed and introduced by Linear Systems over 20 years ago. The company has refined the part’s design and fabrication processes to improve its low noise, matching and Common Mode Rejection Ratio qualities while retaining the linearity and other characteristics sought by audio and other circuit designers.

Linear Integrated Systems, the world-class designer and manufacturer of precision, high-performance, small-signal discrete semiconductors, announced the release of its 2022 Small Signal Discrete Data Book. The Data Book provides all Linear Systems’ datasheets in one spot. The Table of Contents includes product category, part number and part description, so users can browse the entire product line with ease. There is also a dedicated section on packages, highlighting the latest package innovations and packing options.

This article offers the first serving of an amazing DIY project from amplifier experts Bob Cordell and Rick Savas with an upgrade for the legendary Hafler DH-220 lateral MOSFET power amplifier. The design is implemented on two PCBs, one as a drop-in replacement for the original Hafler circuit board and the other as a new board that consolidates all of the output stage wiring and components within the heatsink and under the main PCB. This article was originally published in audioXpress, July 2021

In this DIY project, Andrew C. Russell proposes the X-Altra, a highly refined Moving Coil/Moving Magnet RIAA EQ Preamplifier. This high-performance phono equalizer features an ultra-low noise LSK389B JFET from Linear Systems in the MM front end with switchable gain and resistive loading. This article was originally published in audioXpress, February 2021.

This article describes the design and performance of a high-quality DC-coupled all-JFET amplifier. The circuit was inspired by John Curl and Erno Borbely designs and was built with readily available junction-gate field-effect transistor (JFETs) from Linear Systems. The input stage is the the complementary JFET differential pair, the second stage is symmetrical differential amplifier with two pairs of opposite polarity JFETs, and the output stage is a complementary source follower. The amplifier can drive loads up to 150Ω. This article was originally published in audioXpress, October 2017.

audioXpress February 2021 explains why Microphones have gained Essential Status, and how microphones have a foundational contribution to voice front-ends. Erica Yorga details how Thousands of Virtual Microphones can solve audio conferencing challenges, and Mike Meechan explains how to design high-performance microphone preamplifiers. Brent Butterworth reviews the Widex Moment mRIC RD hearing aids to understand the differences and similarities in the critical sound experience. Michael Steffes explains how to increase the output current for an audio op-amp, and Andrew C. Russell details the X-Altra, a high-performance MC/MM phono equalizer DIY project. Now available in print and digital.

We looked at the most-read articles of 2020 in audioXpress.com (which also includes selected articles from Voice Coil magazine), and we created this Top 10 list of news stories and online articles. 2020 was another record-breaking year for audioXpress.com, with visitors from all over the world returning often to read the more than 6,600 stories available. Which of the topics and stories published online in 2020 were the most popular? Here are the results!

Linear Systems has reintroduced its most popular part, the LSK389, which the Silicon Valley company calls the industry’s first 100% noise tested, ultra-low noise (en = 1.3nV/√Hz (typ), f = 1.0kHz and NBW = 1.0Hz), monolithic dual, n-channel JFET. New test capability screens to a billionth of a ​volt (​nV​/√Hz) of noise now ensures that all ​LSK389s devices produce no burst (RTN or popcorn) noise and ​meet or exceed 1/f and broadband noise specifications.