You Can DIY! Meet the Pentriode

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.

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.