Linear Systems Releases Low-Cost, Low-Noise LS844 JFET for High-Performance Applications

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.

In 2013, Dimitri Danyuk wrote an article that presented apples-to-apples test results for noise densities for several low-noise discrete, SMT, and n-JFETs. In this follow-up article, Danyuk brings us new measurements, updating his design note with measurements of JFET components that appeared more recently on the market. The tests used the same operating conditions so that designers can make a fair comparison for their applications. This article was originally published in audioXpress, December 2018.

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.

Ear Trumpet Labs is a privately owned company in Portland, OR, that makes handcrafted microphones with modern electronics and a striking vintage look. Already with nine different condenser models in the catalogue, Ear Trumpet Labs as announced the release of a new stereo microphone system - with two separate matched capsules mounted at the correct distance for the ORTF stereo recording technique.