New Projects, Reviews, and Glass Audio Special Articles Available with audioXpress May 2020

audioXpress May 2020 Glass Audio/Tube Focus edition is now available. Highlighted on the cover is a review of the RødeTest FuzzMeasure Audio and Acoustic Measurement Software and Ethan Winer's experiments to measure capacitor distortion. For tube enthusiasts, Bill Reeve repurposes an old Shure preamp for line-level duty, and Bruce Heran details how he built his two Mini Blocks tube amplifiers. Mike Rothacher shares an inexpensive MOSFET Follower (MoFo) Class A amplifier project, Richard Honeycutt provides valuable lessons about repairing guitar amplifiers, and there's plenty more audio electronics focused articles. Download now!

Audio Media Research (AMR), the company originally founded by Hartley Peavey as a research and development branch of Peavey Electronics, announced the acquisition of the ReValver guitar amplifier modeling software line from Peavey Electronics. AMR is now a stand-alone entity focused on audio software and digital signal processing for the music creation market, specializing in sound emulation with tube, circuit and component level modeling.

This approach to RIAA equalization results in a high-quality phono preamp featuring the high-transconductance 5842 tubes. The author adapts Erno Borbely's project of a transistorized phono preamp with a vacuum tube implementation. These articles were originally published in audioXpress, October 2003 and January 2010. For this repost, we decided to merge the two articles in one single page.

audioXpress December 2019 dives into the latest wireless audio and DSP platforms and solutions in a dedicated Market Update, followed by a review of the latest Audio Precision APx555 B Series audio analyzer. David Logvin shares his experience with the xCORE VocalFusion development platform by XMOS, while Michael Steffes re-confirms a theory that cascaded amplifier + ADC harmonic distortion combine as voltage swings. Christopher Paul explores alternative approaches to the design of a linear current regulator for audio tube amplifiers, Menno van der Veen details an 18 W single-ended valve amplifier using Trans technology, and Richard Honeycutt investigates whether or not swapping out comparable tubes makes any audible difference in a guitar amplifier’s sound. Download your own copy now!

The November 2019 edition of audioXpress is now available with a wide range of technical topics in audio electronics and design. We review the Benchmark LA4 Line Amplifier and the new Hooke Verse Bluetooth Binaural Recording Headphones. Jan Didden proposes an updated version of his High-Voltage Delay for Tube Amplifiers, and Thomas Zarbo, Jr. explains how to build his Tenacious Bass-8 Powered Subwoofer. And, learn more about Data-Over-Sound, MU amplification topologies, and Auverdion’s Aurora open-source DSP platform. Now available!

Allen & Heath has revealed a new stunning new mixing console design. Avantis is the third model to be based on the company's XCVI FPGA engine, allowing 96kHz operation and puts this next-generation technology available across all its 64 channels and 42 configurable busses, with twin Full HD touchscreens, extensive I/O options and processing from the company's flagship dLive mixing system. The new console is also designed with a surprisingly robust all-metal structure inspired by tubular exo skeletons of super-bikes!

Yes, it was strange to fly to Denver, CO so early in September while most of the industry was on the way to Berlin, Germany for another edition of the International Funkausstellung (IFA), the gigantic consumer electronics and appliance show, which rivals CES in visitor numbers. But the fact is, I don’t regret it in the least. Since the 2019 edition of the Rocky Mountain International Audio Fest (RMAF) changed dates to September 6-8, and the CEDIA Expo takes place shortly after also in Denver, it was a great incentive to opt for Colorado instead.

Do you like vinyl and have more than one turntable? Maybe you are thinking about investing in a new phono preamp and a way to connect both even if it's probably too late to pretend you can learn to be a DJ (hey but the idea is cool anyway...)? Well, here's an interesting option - a compact tube DJ mixer with high-quality components, great sound and the coolest design. The MasterSounds compact Radius Two Valve is a two channel mixer powered by dual triodes. Read on...

David Logvin had the privilege to use, measure, and put to the test the Dayton Audio HTA20BT Hybrid Stereo Tube Amplifier. As he could confirm, there's something special in this amplifier that combines a tube preamp and Class-D power stage, which can also be used as a headphone amplifier, and features a digital media player and Bluetooth streaming capabilities. All at a very affordable price and with the build quality of a Dayton Audio product. This article was originally published in audioXpress, July 2019.

Warwick Acoustics, the company behind the multi-award-winning Sonoma Model One electrostatic headphones has launched the APERIO, its new flagship integrated headphone system. Launched at the 2019 High End show in Munich, Germany, the APERIO headphone system introduces the unique Balanced-Drive High Precision Electrostatic Laminate (BD-HPEL), which takes Warwick's original HPEL to a whole new level, complemented with a completely new electronics unit where nothing is missing. The whole system costs US $24,000 but sounds like a million dollars.