This Tube Preamp Has A Nixie Volume Display

July 25, 2020 by 15 Comments

The pursuit of audiophile hi-fi is one upon which many superlatives and perhaps a little too much money are lavished. But it’s also a field in which the self-builder can produce their own equipment that is as good or often better than that which can be bought, so it provides plenty of interesting projects along the way. [Justin Scott]’s tube preamplifier is a great example, with its novel use of a pair of Nixie tubes to indicate the volume to which it has been set.

The audio side of the preamp comes courtesy of a four-tube kit from tubes 4 hi-fi, in which we notice another tube as power supply rectifier. The case is a beautifully made wooden affair with a professional front panel, but it’s the Nixies which make it a bit special. A high quality motorised potentiometer is used as a volume control, one of its multiple outputs is used as a simple potential divider to provide a voltage. This is read by an Arduino, which in turn drives the Nixies via a BCD-to-decimal decoder. The attention to detail in the whole project is at a very high level, and though he’s not shred any of its audio measurements with us, we’d expect it to sound as good as it looks.

If tube amplifiers interest you, we’ve delved into their design in the past, and it’s worth directing you to Justin’s matching amplifier, as well.

LED Matrix Takes You Down To Nixieland

May 20, 2020 by 2 Comments

It’s said that imitation is the sincerest form of flattery. Sure, there are some who might simply sugarcoat blatant plagiarism with fancy quotes, but there are still cases that come from well-intended, genuine admiration. The Nixie tube with its ember-like glow is a component that definitely gets a lot of such admiration, and being a fond LED enthusiast, [tuenhidiy] saw a perfect opportunity to imitate them with a RGB LED Matrix and build a virtual Nixie clock from it.

What may sound like just displaying images of Nixie tubes on a LED matrix, is actually exactly that. Using the UTFT library and converter, [tuenhidiy] turned pictures of individually lit-up Nixie tube digits into arrays of 16bit RGB values, and shows the current time on an ESP32-controlled 64×64 matrix with them. Providing two different image sizes, you can either place two tubes next to each other, or in a 3×2 arrangement, and of course have plenty of flexibility for future extensions. In the demo video after the break, you can see the two options in action while displaying both the full time, and only the seconds.

Unfortunately, it’s always difficult to judge an LED project through the lens of a camera, especially when looking for the characteristic color of a Nixie tube, but we take [tuenhidiy]’s word that it resembles it a lot better in reality. On the other hand, the pixelated look certainly adds its own charm, so you might as well go completely overboard with the colors — something we’ve seen with a different LED-themed Nixie alternative a little while back.

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Nixie Clock Turns Boombox

April 7, 2020 by 12 Comments

With all the Nixie Clock projects out there, it is truly difficult to come up with something new and unique. Nevertheless, [TheJBW] managed to do so with his Ultimate Nixie Internet Alarm Clock (UNIAC) which definitely does not skimp on cool features.

Although the device does tell time, it is actually a portable boombox that streams music from Spotify using a Raspberry Pi Zero running Mopidy. The housing made from smoked acrylic, together with the IN-12A Nixie Tubes, an IN-13 VU meter, and illuminated pushbuttons give this boombox kind of a 70s/90s mashup retro look. The acrylic housing is special since it consists of only two plates which were bent into shape, resulting in smooth edges in contrast to the often used finger or T-slot design.

For his project [TheJBW] designed a general-purpose Nixie display that can not only show time and date but also the elapsed or remaining track time. He also came up with a Python generated artificial voice that reads you the current playlist. The only problem [TheJBW] has run into was when trying to design a suitable battery system for the device, as the high current draw during start-up can easily cause brownouts. Due to time constraints, he ended up with a MacGyver-style solution by taping a 12 V battery pack from Amazon to the back of the unit.

Among the large variety of Nixie projects we don’t think we have ever seen them in an audio player before except for some attempts of using them as an amplifier. However, it is known that IN-13 tubes make a great VU meter.

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BCD To I2C: Turning A Nixie Counter Into Whatever You Want It To Be

March 28, 2020 by 3 Comments

Whenever a project calls for displaying numbers, a 7-segment display is the classic and straightforward choice. However, if you’re more into a rustic, retro, almost mystical, and steampunky look and feel, it’s hard to beat the warm, orange glow of a Nixie tube. Once doomed as obsolete technology of yesteryear, they have since reclaimed their significance in the hobbyist space, and have become such a frequent and deliberate design choice, that it’s easy to forget that older devices actually used them out of necessity for lack of alternatives. Exhibit A: the impulse counter [soldeerridder] found in the attic that he turned into a general-purpose, I2C controlled display.

Instead of just salvaging the Nixie tubes, [soldeerridder] kept and re-used the original device, with the goal to embed an Intel Edison module and connect it via I2C. Naturally, as the counter is a standalone device containing mainly just a handful of SN74141 drivers and SN7490 BCD counters, there was no I2C connectivity available out of the box. At the same time, the Edison would anyway replace the 7490s functionality, so the solution is simple yet genius: remove the BCD counter ICs and design a custom PCB containing a PCF8574 GPIO expander as drop-in replacement for them, hence allowing to send arbitrary values to the driver ICs via I2C, while keeping everything else in its original shape.

Containing six Nixie tubes, the obvious choice is of course to use it as a clock, but [soldeerridder] wanted more than that. Okay, it does display the time, along with the date, but also some sensor values and even the likes on his project blog. If you want to experiment with Nixie tubes yourself, but lack a matching device, Arduino has you obviously covered. Although, you might as well go the other direction then.

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Just When You Thought There Was Nothing New In Nixie Clocks…

March 3, 2020 by 9 Comments

Nixie clocks have become such a staple in our community as to have become mundane. They’re pretty, but show us something new! It seems [Marcin Saj] has done just that with his offering, because with a bank of 18 IN-2 Nixie tubes he’s telling the time –  but in binary rather than the usual decimal.

The tubes are arranged in three banks of six, the upper registering hours, the middle minutes, and seconds on the lowest. Each one only uses two digits, as you might expect from a binary device they are 0 and 1. Behind is a large PCB with the Nixie sockets, and on the back of that in sockets are a pair of Nixie driver boards, a real-time clock module, temperature sensor module, PSU module, and either a Particle Photon or an Arduino Nano IoT.  This two-option set-up for the choice of dev board is unusual, and there is code for both of them in the GitHub repository.

The result is eye-catching and unusual, and certainly a departure from the usual Nixie digital clock. Hackaday readers are probably more likely than the average Joe or Jane to be able to read binary at a glance, watching it in action in the video below the break is an interesting exercise in testing one’s binary-aptitude.

Meanwhile if binary Nixies are too commonplace, how about binary neon lamps?

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Nixies Adorn A Cold War Relic To Make A Geiger Clock

February 27, 2020 by 22 Comments

Say what you will about the centrally planned economies of the Soviet bloc during the Cold War, but their designs had a brutal style all their own. When one comes across an artifact from that time, like a defunct Polish Geiger counter from 1971, one celebrates that style the only way possible: by sticking Nixies tubes on it and making it into a Geiger clock.

Right off the hop, we’ve got to say that we’re in love with the look of [Tom Sparrow]’s build. And we’ll further stipulate that most of the charm comes from the attractive Bakelite case of the original Geiger counter. This looks like the real deal, with the marbleized look presumably caused by different color resins mixing in the mold. [Tom] did an admirable job bringing back the original shine with some polish and elbow grease; no doubt the decades had taken their toll on the original shine. The meter was gutted to make room for the clockworks, which is an off-the-shelf Nixie module. The tubes stick through holes drilled in the top; a pair of LEDs adorn the front panel and an incandescent bulb provides a warm glow behind the original meter. Combined with the original rotary switch and labels, the whole thing has a great look that’s perfect for a desk.

We’ve featured a lot of retro-classic Nixie builds, from digitizing a 1940s radio to a 1970s multimeter turned into a dice-roller. As for Nixie clocks, we’re just glad to take a break from the Nixie steampunk trend for a bit.

[via Dangerous Prototypes]