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Aug 30, 2026 | 0 comments

Carlsson Speakers: The Ortho-Acoustic Idea That Made the ...

A practical history of Stig Carlsson's Ortho-Acoustic loudspeakers, from the Sonab OA-5 and OD-11 to the wall-coupled OA-50, OA-51, and OA-52.

Aug 18, 2026 | 0 comments

Full-Range Speaker Notch Filters: Correct Topologies, Mea...

published by iwistao · Audio Engineering An LCR network can correct a narrow response peak, but only when the complete source, filter, and driver circuit is designed together. A full-range...

Aug 09, 2026 | 0 comments

How Driver Parameters Determine Full-Range Speaker Dimens...

Published by iwistao · DIY Audio The nominal diameter is only a size category. Actual frame, cutout, mounting, and depth dimensions determine whether the driver fits the baffle; Thiele/Small parameters,...

Aug 07, 2026 | 0 comments

Building a JBL 2420 External Wooden Horn for 12- and 15-I...

Learn how to build and integrate a JBL 2420 wooden horn module with 12- or 15-inch full-range speakers — covering inspection, crossover, placement, and measurement.

Jul 31, 2026 | 0 comments

JBL Control 328C: From Commercial Ceiling Speaker to DIY ...

Published by iwistao · DIY Audio What makes this 8-inch coaxial compression-driver system unusual, why it attracts Ojas-inspired builders, and what to verify before designing a cabinet. Table of Contents...

Jul 29, 2026 | 0 comments

How to Choose the Right Vacuum Tube Amplifier Output Tran...

PUBLISHED BY IWISTAO · TUBE AUDIO ENGINEERING Selecting an output transformer (OPT) is one of the most consequential decisions in a vacuum-tube power amplifier. The OPT reflects the loudspeaker load...

Jul 27, 2026 | 0 comments

Parallel-Feed (Parafeed) Output Transformers: A Practical...

Published by iwistao · Tube Audio Engineering How splitting DC and audio current across two magnetic parts changes the trade-offs of single-ended tube amplifier design. In a single-ended (SE) vacuum-tube...

Jul 22, 2026 | 0 comments

CSR (Qualcomm) Bluetooth Chips and Their Bluetooth Versio...

PUBLISHED BY IWISTAO · Technology / Wireless Audio From the BlueCore era to the Qualcomm QCC and Snapdragon Sound platforms — which Bluetooth specification each CSR / Qualcomm chip implements,...

Jul 12, 2026 | 0 comments

Cathode Resistance in Tube Amplifiers: Bias, Gain, Heat, ...

PUBLISHED BY IWISTAO · Tube Amplifier Fundamentals How the cathode resistor establishes a valve's operating point, shapes gain and frequency response, and protects reliable operation. Table of Contents What the...

Jul 04, 2026 | 0 comments

The 6N2 + Dual-FU19 Vacuum Tube Headphone Amplifier: A Te...

Published by iwistao · Hi-Fi Audio How a 1950s VHF transmitter tube found a second life as one of the most compelling DIY headphone amplifier projects in the audiophile world...

Jun 27, 2026 | 0 comments

The Evolution of Bluetooth Versions: A Complete Technical...

PUBLISHED BY IWISTAO · Technology From 1.0 to 6.3 — what each generation changed, what it did not change, and what matters for wireless HiFi Bluetooth has been the invisible...

Jun 26, 2026 | 0 comments

The Complete Guide to Vacuum Tube Replacement: Types, Sub...

PUBLISHED BY IWISTAO · Audio & Hi-Fi Everything you need to know about replacing vacuum tubes in guitar amplifiers and hi-fi systems — from identifying the right replacements to extending...

Jun 22, 2026 | 0 comments

Nano-Technology Audiophile Fuses: Materials, Engineering ...

PUBLISHED BY IWISTAO · Hi-Fi Audio A critical examination of contact resistance, advanced coatings, vibration-control materials, safety specifications, manufacturer claims, and the limits of current evidence. Table of Contents The...

Jun 13, 2026 | 0 comments

Variable Capacitors in Classic Radios: How Mechanical Tun...

Published by iwistao · Vintage Radio Parts A practical guide to the air-spaced tuning capacitor, the LC resonant circuit, and why a simple rotating plate assembly became central to AM...

Jun 11, 2026 | 2 comments

How a Carbon Fiber CD Tuning Mat Elevates Your Listening ...

PUBLISHED BY IWISTAO · Hi-Fi Audio The science behind ultra-thin carbon fiber disc stabilizers—and why audiophiles are adding them to their CD playback chain for cleaner, more stable sound. Table...

Jun 10, 2026 | 0 comments

Transistor Matching for Audio Amplifiers: Why It Matters ...

PUBLISHED BY IWISTAO · DIY Audio / Electronics A practical guide to matching bipolar transistors in audio circuits — from differential input pairs to parallel output stages, with real-world examples...

Jun 08, 2026 | 0 comments

ALPS Potentiometers in Audio Equipment: RK27, RK163, RK12...

Published by iwistao · Hi-Fi Components From the legendary 27 mm "Blue Velvet" to the compact RK09 — a technical deep-dive into four ALPS series that cover every volume-control need...

May 28, 2026 | 0 comments

Inductors: Principles, Types, and Practical Selection

PUBLISHED BY IWISTAO · Components & Design What inductors do, how core materials and construction affect real-world behaviour, and how to choose the right one for power, RF, and filtering...