The History Of Altec Lansing

May 12, 2026 by Al Williams 1 Comment

If you bought computer audio hardware a few decades ago, you may remember coming across products from Altec Lansing. That you probably haven’t thought of that name in some time doesn’t surprise us, the company has not fared well in recent years and has changed hands multiple times. [The Last Shift] tells the company’s history in a video you can watch below.

James Lansing started Lansing Manufacturing, offering high-end speakers for the fledgling “talkie” movie industry. It had some success, but the depression put them on shaky footing. Meanwhile, a company named All Technical Service Company, or Altec, was a large organization that serviced Western Electric movie theater equipment. Flush with cash, they merged with Lansing Manufacturing to form Altec Lansing. With a large infrastructure and Lansing’s engineering, they became a significant supplier to the military during World War II.

After the war, the company produced a landmark theater speaker system that became the gold standard in theater audio. However, Lansing didn’t like the big company environment and left to found a company that bore his full name, James B. Lansing, which you may know as JBL.

Altec Lansing continued to grow. However, a series of mergers and sales starting in 1969 caused the Altec Lansing company to decline. By the 1990s, Altec Lansing was making cheap PC speakers. A far cry from the gold-standard massive speakers made by the company during its heyday.

We love the history of technology and the people that drove them. Bing Crosby, for example. Or the lesser-known heroes like Edwin Armstrong.

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A Digital Audio Recorder For TOSLink

May 5, 2026 by Jenny List 14 Comments

Every now and then in our travels we come upon a project with such an obvious need that it’s almost a surprise nobody has thought of doing it before. So it is with [Elehobica]’s project, an audio recorder for S/PDIF audio streams. It’s the device you could have used, years ago!

S/PDIF, or its optical fiber cousin TOSLINK, is the digital output you’ll find on the back of Hi-Fi equipment, it’s a serial encoding of an uncompressed digital audio data stream dating from the era when CDs were new. Its relative simplicity may be what’s given it longevity — it’s easy to implement so it plugs into pretty much everything.

Perhaps back in the day it might have been a pain for an 8-bit microprocessor to handle, but in 2026 it’s no bother for a Raspberry Pi Pico. The project is a small PCB with the Pico, a few interface components, and an SD card socket, and it sends what it hears on the input to the card as WAV files. We particularly like its smart sample rate and bit depth detection, and the way it cuts up tracks based on periods of silence. If you work with SPD/IF, this is going to be a useful tool.

Perhaps it could even be fed with a laser!

A Tube Amplifier That’s Oven Ready

April 28, 2026 by Jenny List 25 Comments

The problem with tube based audio is that it has so often been hijacked by people for whom the bragging rights of having a tube amplifier outweigh the benefits, or the sheer fun of building the thing. [Bettina Neumryr] makes a speciality of building projects featured in old electronics magazines, and her latest, a tube amplifier from 1955, is a fantastic antidote to the gold-plated silliness of audiophile tube amplifiers.

Design wise it’s relatively straightforward, with a preamplifier before a two-tube transformerless splitter circuit driving a push-pull output. She dives into the circuit a little, noting its feedback circuit to the cathode of the first splitter tube. There’s an accompanying power supply, a classic tube rectifier design that incorporates a hefty low-pass filter with a giant choke.

We particularly like her choice of chassis — while it’s possible to pay silly money for a tube chassis in 2026 she’s taken a much more down to earth approach with a pair of baking trays. We’re being honest here, they look surprisingly good. Component choices are limited by what’s available so most parts come from the junk box including the output transformer which causes her issues later. There’s a lot of mumbo-jumbo about tube amplifier layout, and she wisely sidesteps some of it.

The result after a few mishaps and a bit of unintended oscillation, is an amp which shows promise, but has distortion due to that transformer. We think she’ll have no problems sourcing a better one, which should bring that distortion figure into the acceptable range. You can watch the whole video below the break, and if that’s got you hooked, you can see one of our own youthful follies.

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Audio-Forward Case Mod Of Classic 90s Portable TV

April 24, 2026 by Bryan Cockfield 8 Comments

The humble cathode ray tube (CRT) was once the technology behind almost all of our televisions and computer displays. Its replacements, from LCD screens to OLED and others, are generally cheaper to make and better to look at. Old televisions were comparatively large as well, but their size can be an advantage for people like [ManicMods] aka [Jeff]. His latest build ditches the CRT from an old Bently portable TV and uses the huge space available in the case for a hi-fi audio system and some other parts that turn it into an impressive portable home theater system.

After removing most of the internals of the TV, the first part to go in is the stereo and subwoofer combo as it takes up the most amount of space. The subwoofer section points downward and the two stereo speakers are mounted to the sides. To free up the most space inside, the new display is mounted forward of the original bezel, with a new 3D printed one helping to hold it in place. Behind it goes a Raspberry Pi, loaded with the moOde audio player, a high quality DAC for audio output, and a 1 TB SSD with [Jeff]’s uncompressed audio library. Most of the ports are extended out to the case including the SD card slot so other operating systems can be loaded on the Pi, and there are a ton of options for hooking up external speakers and displays as well, making it an extremely modular and expandable portable media center.

Also added to the finished product are a few small game controllers, since the Pi is perfectly capable of playing retro games, as well as a small wireless keyboard and trackpad combo. Although the CRT’s demise will be felt harder by some than by others, the original look of the case is preserved somewhat by keeping the original tuning display and locations of the original control buttons and knobs. If preserving the CRTs are of upmost importance, though, this build used a pair of them in a VR headset.

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Heathkit Tuner Saved From Junk Pile

April 4, 2026 by Al Williams 4 Comments

We miss the old Heathkit. You could build equipment that rivaled or even surpassed commercial devices. The cost was usually reasonable and, even if you could get by with less, the satisfaction of using gear you built yourself was worth a lot. Not to mention the knowledge you’d gain and your confidence in troubleshooting should the need arise. So we were jealous of [RCD66] when he found a Heathkit AJ-43C stereo tuner in the recycle bin.

As you can see in the video below, it needed a lot of love to get back to its former self. The device dates from around 1965, when the kit cost $130. In 1965, that was a lot of money. Back then, that would have bought you about four ounces of gold and would have been a great down payment on a $1,500 VW bug.

Things were a bit of a mess, so he removed all the parts and replaced most of them. Unsurprisingly, the electrolytic capacitors all tested bad. The transistors were all germanium, but if they tested good, his plan was to reuse them. There were several PCBs inside, and he made some changes, such as replacing the zener diode power supply with something more modern.

How did it sound? Watch the video and see for yourself. We usually like troubleshooting specific problems on gear like this, but in this case, it was probably smart to just do a total rework.

Heathkit had quite an origin story. This isn’t the first time we’ve seen someone strip and rebuild a Heathkit.

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Mercury Audio Cables, So Nobody Else Has To Do It

April 1, 2026 by Jenny List 66 Comments

We’ve seen our fair share of audiophile tomfoolery here at Hackaday, and we’ve even poked fun at a few of them over the years. Perhaps one of the most outrageously over the top that we’ve so far seen comes from [Pierogi Engineering] who, we’ll grant you not in a spirit of audiophile expectation, has made a set of speaker interconnects using liquid mercury.

In terms of construction they’re transparent tubes filled with mercury and capped off with 4 mm plugs as you might expect. We hear them compared with copper cables and from where we’re sitting we can’t tell any difference, but as we’ve said in the past, the only metrics that matter in this field come from an audio analyzer.

But that’s not what we take away from the video below the break. Being honest for a minute, there was a discussion among Hackaday editors as to whether or not we should feature this story. He’s handling significant quantities of mercury, and it’s probably not over reacting to express concerns about his procedures. We wouldn’t handle mercury like that, and we’d suggest that unless you want to turn your home into a Superfund site, you shouldn’t either. But now someone has, so at least there’s no need for anyone else to answer the question as to whether mercury makes a good interconnect.

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Fixing An Onkyo Receiver With Multiple Faults

March 7, 2026 by Maya Posch 12 Comments

Modern-day receivers are miracles of digital audio and video processing, but compared to their more analog brethren, they can come with a host of new and fascinating faults. The Onkyo TX-SA806 and SR806 receivers were released back in 2008, with [Tony359] recently getting the latter variant in for repair. Described as having weird digital distortion on the audio outputs, this particular issue got fixed by recapping the PCB with all the digital processing in the first video on this receiver, but this left the second issue unaddressed of a persistent hum, which is the topic of the second video on this repair.

Capacitor C5662 in the Onkyo TX-SR608 receiver with a slight bulge. (Credit: Tony359, YouTube) — Capacitor C5662 in the Onkyo TX-SR608 receiver with a slight bulge.

With the easy fix of recapping of the digital board already tried, next was a deep-dive into the receiver’s schematics to figure out where this low-frequency hum was coming from. With it sounding very much like mains frequency hum bleeding through, this was the starting point. Presumably somewhere on the power rails the normal filtering had broken down, so all rails had to be identified and checked for this interference.

With ripple on the 10V and 12V rails as well as the others seemingly in order, it wasn’t clear where the 100 Hz hum was coming from, but people on the BadCaps forum offered some help. After some back and forth it was deduced that the problem was the +15 VA rail, with heavy ripple on it due to a dead capacitor on the +22 V rail that comes straight from a transformer.

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