You Can Use An Old Tape Deck As A Distortion Pedal

September 21, 2023 by Lewin Day 16 Comments

Distorted guitars were a big part of the rock revolution last century; we try to forget about the roll. As a youth, [David Hilowitz] couldn’t afford a loud aggressive amp, a distortion pedal, or even a proper electric guitar. This experience ended up teaching him that you can use random old audio hardware as a distortion effect.

[David’s] guitar journey started when he found a classical guitar on a dumpster. He learned to play, but longed for the sound of a proper electric guitar. Family friends gifted him a solitary pickup, intending he build a guitar, but he simply duct-taped it to his steel-strung classical instead. The only thing he lacked was an amp. He made do with an old stereo system and a record pre-amp. With his his faux-electric guitar plugged into the microphone input, he was blessed with a rudimentary but pleasant distortion that filled his heart with joy.

[David] goes on to explain the concepts behind distorted guitar sounds, and how his home hi-fi was able to serve as a passable starter amp when he was young and couldn’t afford better. He then goes on the hunt for more old gear at a local Goodwill store, finding a neat old tape deck that similarly produced some nice warm distorted tones. In [David’s] experience, old hi-fi gear with microphone inputs can generally do a decent job in this role, with electric guitar pickups typically overloading the preamps which expect a lower-level signal. It’s different to what you’d get from a Big Muff or Boss DS-1, but it’s a neat sound nonetheless.

We’ve looked at distortion effects before, including rolling your own and putting it into production. Video after the break.

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Spinning CRT Makes A 360 Degree Audio Oscilloscope

September 16, 2023 by Dan Maloney 9 Comments

A question for you: if the cathode ray tube had never been invented, what would an oscilloscope look like? We’re not sure ourselves, but it seems like something similar to this mechanical tachyscope display might worked, at least up to a point.

What’s ironic about this scenario is that the tachyscope [Daniel Ross] built actually uses a CRT from a defunct camcorder viewfinder as the light-up bit of what amounts to a large POV display. The CRT’s horizontal coil is disconnected while the vertical coil is attached to the output of a TEA205B audio amplifier. The CRT, its drive electronics, and the amp are mounted to a motorized plastic platter along with a wireless baby monitor, to send audio to the CRT without the need for slip rings — although a Bluetooth module appears to be used for that job in the video below.

Speaking of slip rings, you’d expect one to make an appearance here to transfer power to the platter. [Daniel] used a slip ring for his previous steampunk tachyscope, but this time out he chose a hand-wound air core transformer, with a stationary primary coil and secondary coil mounted on the platter. With a MOSFET exciter on the primary and a bridge rectifier on the secondary, he’s able to get the 12 volts needed to power everything on the platform.

Like most POV displays, this one probably looks better in person than it does in video. But it’s still pretty cool, with the audio waveforms sort of floating in midair as the CRT whizzes around. [Daniel] obviously put a lot of work into this, not least with the balancing necessary to get this running smoothly, so hats off for the effort.

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Building A Rotating Display Plate From A Lazy Susan

September 14, 2023 by Lewin Day 9 Comments

A rotating table is a super nifty tool for all kinds of photography and videography purposes. [Handy Bear] built a super simple example using some parts from IKEA.

The build starts with a Snudda, which is IKEA’s version of a Lazy Susan. It’s fitted with a 3D-printed gear to allow it to be easily driven. The platter is then fitted to a 3D printed base, which also contains the drive electronics, and driven by a small brushed DC gear motor. An off-the-shelf speed controller was employed to allow the speed of the platter to be varied as required.

[Handy Bear] does a good job of explaining how to build the project properly while avoiding the usual pitfalls. In particular, he demonstrates how to fit the gear to the platter without getting it off-axis. We also appreciate a design that can be built virtually anywhere thanks to using commonly-available parts.

We’ve featured other rotating tables before, like this open-ended design that was built on a much larger scale. Video after the break.

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Rocker Bogie Suspension: The Beloved Solution To Extra-Planetary Rovers

September 14, 2023 by Lewin Day 18 Comments

When navigating the vast and unpredictable expanses of outer space, particularly on the alien terrains of distant planets, smart engineering often underlies every major achievement. A paramount example of this is the rocker bogie suspension system. It’s an integral component of NASA’s Mars rovers and has become an iconic feature in its own right. Its success has seen the design adopted by the Indian space program and thousands of hobbyists in turn.

So, what exactly is it that makes rocker bogie suspension such a compelling design solution? Let’s dive into the engineering that makes these six-wheeled wonders so special.

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It’s Time You Built A Smart Pocket Watch

September 13, 2023 by Kristina Panos 39 Comments

There’s just something about a pocket watch that screams class compared to the barbaric act of bending your arm, or the no-fun way of looking at your phone.

But smartwatches are dumb, analog things that mostly look pretty. Or are they? [JGJMatt] proves otherwise with their stunning DIY smart pocket watch. It is essentially a cheap smart watch from Amazon stuffed into the shell of an old pocket watch, but you know it’s not quite that simple.

On the easier side of things, [JGJMatt] had to come up with a 3D-printed bracket to hold the smart watch’s guts. On the harder end of the spectrum, he ended up building the charging port into the crown, where the latch used to be.

This is a beautiful build for sure, and a great way to reuse something that might otherwise end up thrown away or melted down.

Looking for a cool alternative pocket watch that’s a little easier to build? Check out [JGJMatt]’s pocket sundial.

Out With The Circus Animals, In With The Holograms

September 11, 2023 by Maya Posch 25 Comments

As futuristic as holographic technology may sound, in a sense it’s actually already in widespread commercial use. Concerts and similar events already use volumetric projection, with a fine mesh (hologram mesh or gauze) acting as the medium on which the image is projected to give the illusion of a 3D image. The widespread availability of this technology has now enabled Germany’s Roncalli circus to reintroduce (virtual) animals to its shows after ceasing the use of live lions and elephants in 1991 and other animals in 2018.

For the sticklers among us, these are of course not true holograms, as they do not use a recorded wavefront, nor do they seek to recreate a wavefront. Rather they employ as mentioned volumetric projection to essentially project in ‘thin air’, giving the illusion of a tangible object being present. By simultaneously projecting multiple views, to an observer standing outside the projection mesh, it would thus appear that there is a physical, three-dimensional object which can be observed. In the case of the Roncalli circus there are 11 projectors lining the circumference of the mesh.

To a circus the benefits of this approach are of course manifold, as not only do they no longer have to carry lots of animals around every time the circus moves to a new location – along with the on-site demands – but they get to experiment with new shows and new visuals that were never before possible. Ironically, this could mean that after 3D fizzled out at movie theaters, circuses and similar venues may be in a position to make it commonplace again for the masses.

This Keyboard Doesn’t Work Without Game Boy Cartridges

September 11, 2023 by Kristina Panos 9 Comments

Just when we though we’d seen it all when it comes to custom keyboards (or most of it, anyway), along comes [Stu] with the TypeBoy and TypePak. Like the title implies, TypeBoy and TypePak are inseparable.

Let’s talk about TypePak first. Somehow, some way, [Stu] managed to fit the following into an aftermarket Game Boy Advance cartridge: a XIAO BLE microcontroller, a Sharp Memory Display, a shift register, and a LiPo battery. It’s all there in [Stu]’s incredibly detailed blog post linked above.

Amazing, no? And although [Stu] claims that the TypePak is mostly for aesthetics (boy howdy), it will make swapping microcontrollers much easier in the future.

If this looks sort of familiar, you may remember a likely render of [mujimaniac]’s board called the GIGA40 that also employed a cartridge system. Allegedly there is now a working prototype of the GIGA40.

Would you like to give the TypeBoy and TypePak a go? Files are available on GitHub, but this doesn’t seem like a project for the faint of heart.

Speaking of stuffing things in to Game Boy cartridges, check out this SNES cartridge turned hard drive enclosure.

Via KBD