With summer on the horizon it’s time to start thinking about outdoor leisure. [x2Jiggy] is chomping at the bit having recently completed this project. It’s a portable stereo that also gives you somewhere to sit.
Unlike several of these types of project, he didn’t build the system inside of a cooler. Instead, the chassis was built from scratch using MDF. This material is strong and easy to work with, but we’d bet the finished case is a beast to haul around because of the weight. At least there’s a heavy-duty handle on either side so that you and a buddy can split the burden. One nice perk is that it’ll make a sturdy yet comfortable seat thanks the padded and upholstered top.
The audio components that went into it are all automotive parts and shouldn’t mind being jostled during transport. A computer PSU provides the 12V needed by the stereo. But there are a couple of external rail connections if you want to haul around a 12V battery instead.
This is [Wpqrek’s] Commodore 64 modified to go on the road with him. The elderly machine has a special place in his heart as it was what he learned to code on. He performed a series of hacks which house everything necessary to use the machine inside the original case.
Obviously the hack that has the most effect when it comes to portability was swapping a display for the small LCD mounted above the number keys. This was a pretty simple process because the screen, originally intended for a rear view camera in a vehicle, already had a composite video input. To emulate the floppy disc drive he’s using an SD card via an sd2iec board which he laid out himself. Rounding up the alterations is a stereo SID. The second channel uses the pre-amp circuit cut from a second C64. This audio hardware will let him do cool things like playing some classic Zeppelin.
You can get a video tour of these alterations after the break.
Continue reading “Making a Commodore 64 portable”
[Michael] wanted a stereo that he could use outside, be it at the beach, beside the pool, or while tailgating. He decided to build this boom box himself, and didn’t cut any corners when it came to a professional looking finish.
Because of the locale in which he plans to use the stereo he went with a set of marine speakers. They’ll have no problem standing up to water, and since they’re used in boats they should also be able to take a beating during transport. To feed it he uses a Lepai T amp which is seen above.
After cutting each piece of the case out of MDF he started working on the openings to receive the components. This involved quite a number of layout lines and some work with a compass to map out the circular openings. He built a recessed panel on the back to interface the power cord for charging. Inside is an 18 Ah battery. A set of switches lets him turn on the charger and choose between powering the amp from battery or from the power cord.
Here are two different briefcase speaker projects. [Dale] built the offering on the right back in high school and the upgraded version 2.0 more recently. He was inspired to send in a tip for the projects after seeing yesterday’s suitcase full of tunes.
The first version uses a pair of speakers pulled out of a car at the junkyard. They’re mounted on some particle board which beefs up the side of the plastic briefcase. The amplifier that drives it is mounted inside the case along with a battery to power the system. [Dale] included a crude storage bracket for the input cable and since the amp can drive four speakers there are connectors on the outside for two more.
Version two has quite a bit more polish. He doesn’t show that one off quite as much, but you can see there is a LED strip on the case that serves as a VU meter, as well as a numeric display which might be battery voltage? He mentions that this blows away any commercially available systems his coworkers have brought to the job site.
Video of both rigs can be found after the break.
Continue reading “A pair of briefcase boombox builds”
We love seeing repairs and always marvel at the ability to track down the problem. [Todd] seems to have a knack for this. He was met with a lot of adversity when trying to get the Vacuum Fluorescent Display working on his car stereo. A lot of persistence, and a little bit of taking the easier way out let him accomplish his goal.
The head unit is out of his 1994 Jeep. He knew the radio functionality still worked, but the display was completely dark. After getting it out of the dashboard he connected it to a bench supply and started probing around. He established that the data lines were still working by setting the radio to auto scan mode and testing with a multimeter. When he went to measure the cathode pins he didn’t get any reading. It seems the driver which supplies that signal is burnt out.
One easy fix would be to replace the parts from a scavenged unit. [Todd] hit the junkyard and picked up one from a Jeep that was just one model year apart from his. Alas, they weren’t exactly the same, and although he swapped out a chip (using a neat heated solder sucker) it didn’t work. In the end he simply dropped in a power resistor to use the 12V rail as a 1V at 0.1A source for the filament.
You can see his repair extravaganza in the video after the break. If you’re looking for tips on scavenging these types of displays check out this post.
Continue reading “Repairing a VFD driver on a car stereo”
[PC486] wanted to add Bluetooth to a simple shelf stereo system. But if you’re going to go wireless, why not develop an all-in-one solution. His adapter turns on the stereo and feeds it audio all from a smart phone.
This is his roommate’s hardware so cracking it open and grabbing an iron wasn’t really an option. He needed a way to control the system without any permanent alterations. Since the unit has IR remote control capabilities that’s the most obvious way to go. But the original remote is long gone so he had to hit the Internet. Luckily the remote control codes are in the LIRC repository. He grabbed a small microcontroller, an ATtiny25, and wired up an IR led to send commands to the unit.
Next he examined the Bluetooth audio receiver board he planned to used in the project. It’s got an LED that lights up when connected to another Bluetooth device. The microcontroller knows when to turn the stereo on and when to shut it off again by monitoring that LED with a pin interrupt. Check out the final results in the clip after the break.
Continue reading “Wireless stereo add-on turns on receiver and pipes in some music”
Here’s a way of transmitting audio that makes it virtually impossible for someone else to listen in. Instead of sending radio waves bouncing all over creation, this uses the focused light of a laser to transmit audio. In the image above you can see the silver cylinder which houses the laser diode. It is focusing the beam on a light dependent resistor to the right which looks almost like a red LED due to the intensity of the light.
The simplicity of this circuit is fascinating. On the receiving end there is no more than the LDR, a 1.5V power source, and a headphone jack. The transmitter is not much more complicated than that. It includes an audio output transformer which boosts the resistance of the audio signal. This increase in resistance ensures that the laser diode modulates enough to affect the LDR on the receiving end. The transmitter uses a 3.3V supply. Check out the video after the break to hear the high quality of audio coming through the setup.
Once you’re done playing around with the transmitter you might try turning the laser into a remote control for your stereo.
Continue reading “A laser audio transmitter”