Linear Systems Reintroduces LSK389 Ultra-Low Noise N-Channel JFET

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.

Røde Microphones introduced brand new TF-5 Premium Matched Pair Cardioid Microphones, designed in collaboration with legendary, Grammy Award-winning sound engineer Tony Faulkner. The TF-5 package includes the matched pair of microphones, stereo bar and all accessories needed for live sound or recording situations. According to the company, the TF-5 represents a new standard in small diaphragm condenser microphones, imagined and designed in collaboration with Tony Faulkner and manufactured at Røde’s state-of-the-art facility in Sydney.

For this last edition of 2018, audioXpress compiled a Voice Market Update that explores some of the latest developments and platforms for voice processing, with contributed articles from world-renowned experts in voice. The December 2018 edition reviews the ZOTL Ultralinear Power Amplifier from Linear Tube Audio; explains how to explore Soviet Germanium Transistors; and measures new SMT Low-Voltage JFETs. This is an edition you don't want to miss.

High-end studio processor manufacturer elysia announced availability of its new skulpter 500 sound shaping preamp — pushing its range of 500 Series recording hardware into another area of processing. According to the German company, the skulpter 500 is high quality recording preamp based on single resistors controlling a fully discrete Class-A amplifier capable of complementing any microphone or high-impedance instrumental source and adding two variable saturation/filter stages and an intelligent onboard compressor.

This project is based on Erno Borbely’s EB-602/210 single-ended pure Class A amplifier and is capable of driving headphones between 32 and 600Ω. It consists of two identical but separate amps laid out on the same PCB. The schematic is the same as Erno’s extremely popular hybrid tube/MOSFET line amp, published in Glass Audio 1/98. However, the dual triode at the input is replaced by a dual JFET (SK389). This article was originally published in audioXpress, July 2004.

In 2008, Nelson Pass submitted an article on its new F5 power amplifier design to audioXpress. At the time, he wrote: “I feel that it’s important to support AudioXpress, a magazine with which I have a 35 year history, and which also serves as a mainstay for the DIY community. Lately they have kindly printed projects that I had already posted on the web, but I decided that they deserve a little better than that.” Effectively, the F5 project was published in May 2008 and had a huge impact on the global DIY community and certainly contributed for the fact that audioXpress is still around today.

Harman’s Mark Levinson had much to show at the 2016 High End show in Munich. Adding to the 519 high-resolution and streaming audio player, and the 526 dual-monaural preamp with high resolution DAC and phono stage, both previewed at CES 2016, the revitalized company now introduced the 523, a version of the 526 without the DAC, and launched the 585 dual-monaural integrated amplifier with Precision Link DAC, and the 536 and 534, monaural and dual monaural amplifiers.

This article continues the classic JFETs series of articles by Erno Borbely and introduces one of his starter kits with an all-JFET line amp. Originally published in audioXpress March 2005 this is an essential reading to understand the “building blocks” of the “Borbely amplifiers”.

The basic circuits on which Erno Borbely based most of his projects are described in “JFETs: The New Frontiers, Part I and II,” published in Audio Electronics AE 5/99 and 6/99, and “All-FET Line Amp,” published in audioXpress May 2002. As the author admits, these were the “building blocks” on which many - if not all - of his amplifiers are based. This articles continues his JFETs series and was originally published in Audio Electronics, Vol 5 1999.

The basic circuits on which Erno Borbely based most of his projects are described in “JFETs: The New Frontiers, Part I and II,” published in Audio Electronics AE 5/99 and 6/99. Referring to these articles frequently, the author admits, these were the “building blocks” on which many - if not all - of his amplifiers are based. This article is the first part, as originally published in Audio Electronics, Vol. 5 1999.