FaitalPRO 2FE24 Pro Sound 2.5" Full-Range

The focus for this Test Bench is the 2FE24 2.5” full-range driver from FaitalPRO, an interesting small diameter full-range design suitable for pro audio applications such as PA line source speakers. The 2FE24 is built on a proprietary injection-molded polycarbonate four-spoke frame, and the cone assembly consists of an uncoated paper cone and dust cap, low loss half-roll NBR surround, and elevated cloth spider. Powering the cone assembly is a neodymium ring magnet and a milled return cup fitted to a 19mm diameter voice coil wound with aluminum wire on a Kapton former. This article was originally published in Voice Coil, May 2022.

Renowned tube expert Michael Boele offers his long-term review of a pair of 2021 new production 300B directly heated power triodes. For 10 months, Boele had the opportunity to live with and extensively use a pair of these 300Bs and his impressions and extensive testing could be directly contrasted with his considerable collection of 300B tubes - Chinese, Russian, Czech and Slovak clones, as well as several pairs of Westrex/Western Electric reissues, and two “old stock” Western Electrics. This article was originally published in audioXpress, May 2022.

In this article, Vance Dickason characterizes the E180HE-44 woofer, from the Dayton Audio Epique lineup. As with the E150HE from the same range, the E180HE-44 uses the patented Multiple Magnet Air Gap (MMAG) technology, invented by Enrique Stiles and patented by Step Technologies. The E180HE is a scaled up (7") version of the E150HE, and has a similar feature set but with a secondary magnet system comprised of six ferrite disks, which act as magnetic “diodes” pulling the flux from the main magnet into the top 7mm gap. This article was originally published in Voice Coil, May 2022.

This DIY-focused article introduces the Pentriode, a concept to explore the familiar idea of connecting commonly available pentode tubes as triodes, creating a circuit that excels in linearity. The Pentriode is formed by making one simple change to connect the screen grid to the cathode of a cathode follower. The article proposes different possible approaches, including for a mu stage, a design that the author previously wrote about for audioXpress. This article was originally published in audioXpress, May 2022.

This is the second article in a fascinating DIY journey of a guitar-controlled, all-analog synthesizer project that will include multiple stages and modules. Following a Sample & Hold circuit designed to retrieve previous voltages that no longer exist, this article details voltage control and how the playing is converted to voltages and back to frequency.

It's time for the Glass Audio/Tube Focus edition of audioXpress. In this issue, Michael Boele shares his long-term review of a pair of 2021 new production Western Electric 300Bs, Merlin Blencowe explains how to add Bluetooth to a Tube Amp, and Alan Kimmel introduces us to the possibilities of the Pentriode. There's also a Market Update report on vinyl sales and the latest trends in turntables and cartridges, as well as a review by Stuart Yaniger of the latest Orchard Audio Starkrimson Stereo Ultra GaN-based amplifier.