Record Players Explained For The Streaming Generation

March 3, 2017 by Jenny List 68 Comments

How do you consume your music, these days? Aside from on the radio, that is. Do you play MP3 or other files on your phone and computer, or perhaps do you stream from an online service? If you’re really at the cutting edge though you’ll do none of those things, because you’ll be playing it on vinyl.

The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Dydric [CC BY-SA 2.5)], via Wikimedia Commons. — The legendary Technics SL1200 direct-drive turntable, as used by countless DJs. Photo by Dydric CC-BY-SA 2.5

A few years ago reporting on a resurgence of sales of vinyl records was something you would never have expected to see, but consumer tastes are unpredictable. Our red-trousered and extravagantly bearded hipster friends have rediscovered the glories of the format, and as a result it’s popping up everywhere. For those of us who are old enough to have genuinely been into the format before it was cool again, the sight of Sergeant Pepper and Led Zeppelin II on 12″ at outrageous prices on a stand at the local supermarket is a source of amusement. It’s good to see your first love back in vogue again, but is it really the £20($25) per album kind of good?

With the turntable having disappeared as an integral part of the typical hi-fi setup the new vinyl enthusiast is faced with a poor choice of equipment. Often the best available without spending serious money at an audiophile store is a USB device with the cheapest possible manufacture, from which the playback will be mediocre at best. We’ve lost the body of collective knowledge about what makes a good turntable to almost thirty years of CDs and MP3s, so perhaps it’s time for a quick primer.

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Adding Stereo VU Meters To A Turntable

January 28, 2017 by Jenny List 8 Comments

A pleasing development for those with an interest in audio equipment from decades past has been the recent resurgence in popularity of vinyl records. Whether you cleave to the view that they possess better sound quality or you simply like the experience of a 12″ disk with full-size cover art and sleeve notes, you can now indulge yourself with good old-fashioned LPs being back on the shelves.

[Michael Duerinckx] is a fan of older trance records, and has an Ion Pure LP turntable which is fortunately for him not such an exclusive piece of audio equipment that it can’t be readily hacked. The hack he’s applied to it is a relatively simple one but nonetheless rather attractive, he’s added a set of LED VU meters in a ring round the edge of the platter.

Behind the LEDs is the trusty LM3915, an integrated circuit which will no doubt be familiar to any reader whose earlier life was spent among 1970s and 1980s audio gear. Internally it’s a stack of comparators and a resistor ladder, and it simply turns on the required number of outputs to match the level on its input. He’s put a pair of them on a little PCB with an associated PSU regulator, and mounted the LEDs in a row of holes drilled in the MDF base board of the turntable following the edge of the platter. Power and audio come from the turntable’s circuit board, which contains a preamplifier and the USB audio circuitry. A traditional turntable with a low-level output would not be able to drive an LM3915 directly.

This is a relatively straightforward project and the turntable itself isn’t necessarily the most accomplished on the market, but it’s very neatly executed and looks rather pretty.

Turntable projects are not as common as you’d expect here at Hackaday, but we’ve had a few. There was this concrete example for instance, and a very pretty one using layered plywood.

Courtesy of SoMakeIt, Southampton Makerspace.

Conductive Paint Turns Pizza Box Into DJ Mixing Station

October 2, 2016 by Cameron Coward 20 Comments

Conductive paints and inks have been around for quite sometime, and the internet abounds with examples of cool projects you can use them for. They’re well suited to quick and fun prototypes, educational workshops, and temporary toys. But, as cool as conductive paint is, it’s not usually the kind of thing that gets people excited at parties.

Well, until now that is. Adafruit has published a dope guide for building a bomb-diggity DJ mixing station out of a pizza box, conductive paint, and a Circuit Playground board. The guide walks you through how to properly apply the conductive paint (in this case using a stencil to lay it onto a cardboard pizza box), wire it up using the Circuit Playground, and integrate it into popular DJ software.

Sure, your sister’s “professional” DJ boyfriend may scoff at it, but it’ll still let you lay down some boss beats. And, when the bass drops nobody will care that you’re scratching a Domino’s box. Of course, there are other options out there if you want a more permanent solution.

A Beautiful Turntable With A Heart Of Concrete

September 30, 2016 by Jenny List 23 Comments

On the face of it, playing a vinyl record is a simple process. You simply mount it on a turntable rotating at the right speed, and insert a needle into the groove. A learning exercise for youngsters used to be a passable attempt at a record player on the kitchen table with a pencil, a large cork, a sharpened matchstick, and a piece of paper. It sounded awful, but it demonstrated well how the audio was recorded.

If you have ever looked into the operation of a more conventional turntable though you’ll know that a little more care and attention is needed. There are many factors which affect the quality of the sound, and you quickly become obsessive about tracking, and sources of the tiniest vibration. Someone who has followed this path is [Mjhara], who has made a very high quality turntable. There is an unusual choice in this project: the tonearm is part of the build rather than fitting a commercial item like most turntable projects.

The platter is machined from a piece of rosewood, weighted and balanced with lead shot, and laminated between two sheets of brass. It sits on a bearing aided by a ring of opposing magnets, and is belt driven by a two-phase induction motor. The base of the turntable is cast as a single piece of concrete, the idea being that the extra weight will aid the damping of vibrations. The tonearm is machined from a piece of wood, and its pivot from brass. The tonearm bearing is a ballpoint pen, a surprising yet inspired choice .

Sometimes audiophiles take their quest for better sound to extremes, and justification for their expenditure can be very subjective. But [Mjhara] assures us that this turntable has an exceptionally good sound, and it is certainly a thing of beauty. Full details are in the Imgur gallery embedded below the break.

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Turntable Turns Waveform Generator

August 19, 2016 by Moritz Walter 23 Comments

In need of a waveform generator for another project, [David Cook] crammed out the old turntable to modify it for a handy hack: By adding a simple reflectance sensor to the pickup he turned it into a waveform generator that optically plays back arbitrary waveforms from printed paper discs.

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Hacked Turntable Rotates Humans For 3D Scanning

February 25, 2016 by Anool Mahidharia 12 Comments

If you are from the 70’s, you’ll probably remember the Disco Body Shaper or the Aerobic Body Shaper exerciser devices that were the rage of the day. Basically, Lazy Susan turntables on which humans could stand and twist away to burn fat. The results were suspect, but [Daniel Kucera] thought one of them would be ideal in 2016 to build a heavy-duty turntable to allow full body scanning.

He had already tried a few other ideas and failed, so it was worth giving this a shot, since it cost just 10 bucks to buy one. The plan was to use a motor to provide friction drive along the circumference of the turntable platform. For this, he used a high torque motor with a gear on the output shaft. From the looks of it, he attached a Meccano plate to the base, and mounted the motor to this plate. A large spring keeps the motor pressed against the rim of the turntable. A strip of rubber scavenged from a bicycle tube was glued along the side of the turntable to provide some friction to the gear drive. The turntable is placed on two thick pieces of foam, to provide clearance for the motor. We aren’t sure if a toothed gear is the best choice to drive this thing, but a hacker’s gotta use what he’s got. He’s clocking 190 seconds for a full rotation, but he still hasn’t posted any scan results from the Android scanner software that he is working on. This one, for sure, doesn’t qualify for a “it’s not a hack” comment.

Scratching Vinyl Straddles Physical And Digital Realms

December 21, 2015 by Elliot Williams 10 Comments

The life of a modern DJ is hard. [Gergely] loves his apps, but the MIDI controller that works with the app feels wrong when he’s scratching, and the best physical interfaces for scratching only work with their dedicated machines. [Gergely]’s blog documents his adventures in building an interface to drive his iPad apps from a physical turntable. But be warned, there’s a lot here and your best bet is to start at the beginning of the blog (scroll down) and work your way up. Or just let us guide you through it.

In one of his earliest posts he lays out his ideal solution: a black box that interprets time-code vinyl records and emulates the MIDI output of the sub-par MIDI controller. Sounds easy, right? [Gergely] gets the MIDI side working fairly early on, because it’s comparatively simple to sniff USB traffic and emulate it. So now he’s got control over the MIDI-driven app, and the hard part of interfacing with the real world began.

After experimenting a lot with timecode vinyl, [Gergely] gives up on that and looks for an easier alternative. He also considers using an optical mouse, but that turns out to be a dead-end as well. Finally, [Gergely] settled on using a Tascam TT-M1, which is basically an optical encoder that sits on top of the record, and that makes the microcontroller’s job a lot easier. You can see the result in the video below the break.

And then in a surprise ending worthy of M. Night (“I see dead people”) Shyamalan he pulls timecode vinyl out of the grave, builds up a small hardware translator, and gets his original plan working. But we have the feeling that he’s not done yet: he also made a 3D printed optical-mouse holder.

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