[Feature] The Latest DIY Amplifiers You Can Build: Three Phono Equalizers for Optical Cartridges
Playback using optical cartridges with LED light sources and photodiode receivers—now attracting attention as a breakthrough in analog reproduction—requires a dedicated phono equalizer.
At first, users had no choice but to rely on commercial products, but research by pioneers led by Akihiko Kaneda has helped create the conditions for amateur DIY construction. This feature introduces the current technical frontier through three examples of DIY vacuum-tube phono equalizer amplifiers for optical cartridges.
• A Vacuum-Tube Approach to the Latest Device:
Dedicated phono equalizer amplifier for the DS-E3 optical cartridge — Hiroshi Ueno
• Optical-cartridge-dedicated equalizer amplifier using WE 396A, op-amps, a balanced-output IC, and an ultra-low-noise power-supply module — Yasuo Iwamura
• Dual-cartridge vacuum-tube preamplifier compatible with optical and MC cartridges, featuring a 420A differential input stage and 396A SEPP output stage — Akihiko Kaneda
• Listening tests of three builder-made phono equalizers for optical cartridges — Takashi Iwai
• Latest list of optical cartridges and phono equalizers
[Original Sound System Construction]
• 8045G single-ended direct-coupled power amplifier with dual power supplies for stable operation — Susumu Soya
• SV811-10 single-ended power amplifier using a Russian directly heated triode, cathode-follower drive, and Class A2 operation for 6.5W output — Masaru Nagashima
• Multifunction preamplifier using 12AX7 and 12AU7, with phono equalizer, tone control, line output, and headphone output — Kazutomo Kobayashi
• Building the ideal system for a modified driver unit:
Experiment in converting the Diatone P-610 to field-coil operation [Part 2]
Construction of the enclosure and field-coil power supply — Hiroshi Ueno
• Audio amplifier design and construction support using a personal computer [Part 64]
Building a multi-amplifier system (4) — Heisuke Ikeda
• Building high-performance, high-sound-quality speakers based on the latest measurement and design [Part 39]
Building a compact 2-way speaker using a SEAS magnesium woofer (conclusion):
Measurement and exterior finishing — Kohei Suzuki
• Designing and building compact speakers for high efficiency and high sound quality [Part 199] — Takahisa Ozawa
[Audio Technology]
• SOULNOTE: Circuit technology of the Series 1 / Series 2 ver.2 — Isao Shibasaki
• The history of audio manufacturers as seen through hardware evolution [Part 108]
Luxman’s path from its 90th to 100th anniversary (3): Semiconductor integrated amplifiers — Isao Shibasaki
• Discovering true characteristics through measured data:
Measuring vacuum-tube characteristic curves (5)
Characteristics of the 4-65A in triode connection — Maki Kubo
• From junk to practical use again:
Audio equipment repair diary [Part 27]
Maintenance of the Yamaha FM/AM tuner T-7 — Hideyuki Sakai
[MJ Best Audio Components]
• SOULNOTE A-1 ver.2 integrated amplifier
• Fundamental aina integrated amplifier
• Fidelix ARIETTA 2-way speaker system
• Yamamoto Sound Craft BX-70-LE8T enclosure for LE8T
• SOULNOTE D-1 ver.2 D/A converter
[MJ Report]
• Accuphase new product information: DC-500 / DG-78
• Fidelix FRT-120K super tweeter
New Product News
[Music / Acoustic Spaces / Pro Audio]
Dream Listening Rooms for the Pursuit of Hi-Fi No.655
Listening to a fully horn-loaded coaxial speaker system at a design museum — Devon Turnbull
[Audio & Software Guide]
• This year it will be held in April! A gathering of old and new technologies
The 8th MJ Audio Festival
• “Notes for Re-entering the World of Audio” [Part 9]
How to get more comfortable, better sound from your audio system: Basics 2 — Yutaka Masaki
• The audio style of the future:
Bluesound’s high-resolution streamer NODE ICON — Takashi Iwai
• Reviews of new classical releases — Naoya Hirabayashi, Ikuo Tsunoda, Chigaku Inoue
• Reviews of new jazz, rock, and pop releases — Masahiro Imai, Yoshinobu Morita
• Audio Is Troublesome (118)
Fascinated by open-reel tape recorders — Kazuo Harashima
• Visiting famous pieces in the forest of cinema No.206/207 — Masafumi Yanagisawa
• Classic masterpieces and great performances beyond audio (184)
The 125th anniversary of the premiere: Mahler’s Symphony No.4 — Naoya Hirabayashi
and more
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MJ Radio and Experiments April 2026 Spring Issue | Seibundo Shinkosha Co., Ltd. (seibundo-shinkosha.net)