You Can DIY! X-Altra MC-MM RIAA EQ Preamp - Part 1

In this DIY project, Andrew C. Russell proposes the X-Altra, a highly refined Moving Coil/Moving Magnet RIAA EQ Preamplifier. This high-performance phono equalizer features an ultra-low noise LSK389B JFET from Linear Systems in the MM front end with switchable gain and resistive loading. This article was originally published in audioXpress, February 2021.

Following the announcement of the Phono Box RS2 reference class preamp, Pro-Ject has confirmed the launch in the North-American market of a series of phono products and accessories, some of which were released previously in Europe. Those included the Phono Box S2 Ultra discrete MM/MC phono preamplifier, the limited edition Phono Box Ultra 500 in polished chrome, and the Sweep It E and Sweep It S2 record brooms to clean vinyl while records are playing.

A renowned manufacturer of phono cartridges and tonearms since the company's foundation in Japan, Audio-Technica announced the introduction of its AT-PEQ30 phono equalizer, designed to add a phono stage to a turntable setup or to serve as an upgrade from a turntable's built-in phono preamp. The AT-PEQ30 accommodates MM (moving magnet) and MC (moving coil) phono cartridges and according to the company, its circuits were designed for "superlative sound quality."

We know vinyl is trending and that turntable options are expanding in every price segment. But after the return of some "ghosts" from the distant past (in electronics, basically everything before the eighties), Bang & Olufsen now tops the list of "resurrections" with the rebirth of its Beogram 4000c Recreated Limited Edition. Bang & Olufsen says it's the return of an icon, "reimagined for contemporary homes," and the start of a new approach for the Danish brand.

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.

This article explains the methods of cutting disc records, the characteristics of magnetic phono cartridges, and how their combined response determines the required playback equalization. The article is based on a paper the author presented at the May 1996 conference of the Association for Recorded Sound Collections (ARSC) in Kansas City, and was first published in the Fall 1996 issue of the ARSC Journal. Later, the article was featured as part of "The LP Is Back!" compilation book published in 1999 by The Audio Amateur company.

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...

As part of its ongoing 30th-anniversary celebrations in 2019, Chord Electronics has unveiled Huei, an all-new phono preamp that distills three decades of amplifier development and audio engineering expertise into a high-performance yet space-saving chassis. Entirely conceived, engineered and manufactured in Great Britain, the new microprocessor-controlled Chord Huei has been carefully designed to provide turntables with the same high standards of amplification the company has become known for over the past 30 years.

Boulder Amplifiers from Louisville, Colorado, announced the immediate release and shipment of the 2108 Phono Preamplifier, the brand’s reference level phono preamplifier. The 2108, is Boulder’s second generation of 2000-level phono preamplifier, following and improving upon the multiple award winning 2008 phono stage. All possible options and improvements for different ages of vinyl and cartridges have been considered for this new phono reference-level preamplifier.

I completed the design and construction of an archival phono preamplifier, which provides variable equalization along with several other operational necessities for playing vintage records (78-rpm discs, pre-RIAA LPs, lacquer transcription discs, and so on). When it came to selecting topologies for the balanced inputs and outputs, I ruled out transformers due to high cost, physical bulk, and weight. The most practical choice, in terms of size and cost, are the balanced line driver and receiver ICs made by THAT Corporation. This article was originally published in audioXpress, June 2010