A man playing a pipe organ through a MIDI keyboard

How To Move A Full-Sized Church Organ From A House To A Museum

May 31, 2022 by Robin Kearey 11 Comments

As electronics hobbyists we are grateful to our spouses and flatmates who gracefully tolerate all of our weird equipment and chaotic projects in their homes. But it takes a different level of dedication to share one’s home with a pipe organ enthusiast: back in the 1970s, one organist in Bristol went to the effort of installing a full-sized church organ into their house, effectively turning the modest dwelling into one giant musical instrument. Recently however, the house passed on to new owners who, understandably anxious to reclaim some space, listed the whole system on eBay.

A pipe organ installed into an attic — No cash in this attic; just lots of zinc pipes and pneumatic tubing.

Thankfully, the auction was won not by some scrap metal dealer but by [Look Mum No Computer], our favourite expert on odd musical instruments. He drove out all the way from Kent to help disassemble the organ and stuff the dozens of pipes, miles of cable and numerous valves, tubes, latches and switches into his van. Once back home, he faced the daunting task of reassembling the whole lot into something capable of playing music, which he’s currently documenting in a video series.

The organ’s new home is This Museum Is (Not) Obsolete, where it has its own room decorated in a style similar to the house it spent much of its life in. The first step to getting it working was to fire up the blower, which is effectively a powerful electric air pump together with a pressure-regulating mechanism. Once this was working, one row of pipes was added to test the actuation system. This consists of a set of solenoids that simply open or close the air supply to each pipe. [LMNC] still had an Arduino-based organ driver system from an earlier project, which allowed him to connect a MIDI keyboard to the partially-complete instrument and play a few notes on it.

There’s still a lot to be done, but we’re definitely impressed by what [LMNC] has achieved so far and can’t wait to see the organ restored to its former glory. We already knew that you could control pipe organs through MIDI, and we’ve seen much smaller organs built from scratch. Thanks for the tip, [hackbyte]! Continue reading “How To Move A Full-Sized Church Organ From A House To A Museum” →

Relax And Enjoy This Simple Drone Synthesizer

May 29, 2022 by Dan Maloney 2 Comments

You’d think that a synthesizer that makes as much noise and sports as many knobs as this one would have more than a dozen transistors on board. Surely the circuit behind the panel is complex, and there must be at least a couple of 555 timers back there, right?

But no, the “Box of Beezz” that [lonesoulsurfer] came up with is remarkably simple. It takes inspiration from a [Look Mum No Computer] circuit called the “Circle Drone of Doom,” which used six switchable relaxation oscillators to make some pretty cool sounds. The Box of Beezz steps that up a bit, with four oscillators in three switchable banks in the final version. Each oscillator has but one transistor with a floating base connection and a simple RC network on the collector. The sawtooth outputs of these relaxation oscillators can be adjusted and summed together, resulting in some surprisingly complex sounds. Check out the video below for a bit of the synth’s repertoire — we’d swear that there are points where we can hear elements of the THX Deep Note in there.

We poked around a bit to understand these oscillators, and it looks like these qualify as avalanche relaxation oscillators. [lonesolesurfer]’s notes indicate that SS9018 transistors should be used, but in the photos they appear to all be 2N4401s. We’re not sure how long the transistors will last operating in the avalanche mode, but if they quit, maybe some neon tubes would work instead.

Continue reading “Relax And Enjoy This Simple Drone Synthesizer” →

Upcycled Practice Amp Build Goes To Eleven

May 26, 2022 by Dan Maloney 19 Comments

What do you call someone who gives the toddler in your life a musical instrument as a gift? In most cases, “mortal enemy” is the correct answer, but not everyone feels quite so curmudgeonly, and might even attempt to turn up the volume a bit. Such is the case with this wonderfully detailed practice amp for the grandkids’ electric ukelele.

~~The aptly named [packrat]~~ [Professor Mayhem] really made this build a tour de force of scrap bin sourcing. The amp is built around a module salvaged from an old TV, a stereo Class-D amp that was modified to provide 30 watts output and a volume control. The driver came from a flood-damaged speaker unit, and the power supply from a gutted wall wart. The case was built with scrap plywood and covered with pebble-grain fabric to give it that pro audio look, while the chassis for the electronics was bent from a piece of sheet steel.

But it’s the tiny details that really sell this project. Everything from the pilot light to the pointer knob screams 1970s, as do the painstaking front panel lettering and vinyl “Monkeydyne” logo. [Professor Mayhem] even went the extra mile to create an etched-brass serial number plate, a mock specs and safety label, and even a QA inspection tag that was (sort of) stapled inside the cabinet.

We tip our hats to [Professor Mayhem] for this four-month labor of love and obvious nostalgia trip, which the kids are sure to love. [Professor Mayhem] does admit that some will argue with his decision to use a Class D amp and a switch-mode power supply, but let’s be real — for the application, it’s probably more than sufficient.

Thanks for the tip, [packrat].

Sound Generation Board Makes The Tunes

May 20, 2022 by Al Williams 4 Comments

[Mcjack123] has been getting into chiptunes lately and realized that his original interest started in 2018 when he used an Arduino to turn a TI-84 calculator into a sound machine. His latest iteration is a custom-designed soundboard and he takes us through the design and construction of it in a recent post.

The work models classic sound generators like the 2A03 or the Commodore 64 SID. You have a bunch of simple waveform generators along with filters and modulators to make various effects. These boards eventually gave way to FM synthesis devices like the Yamaha OPL2 and OPL3 chips. All of these cards accepted commands and generated audio on their own. More modern boards are more likely to simply convert digital data from the computer into audio.

Continue reading “Sound Generation Board Makes The Tunes” →

MIDI Controller Looks Good, Enables Your Air Guitar Habit

May 18, 2022 by Al Williams 8 Comments

We all want to be guitar heroes, but most of us have to settle for letting a MIDI board play our riffs using a MIDI controller. [Joris] thinks a MIDI controller should look like a cool instrument and thus the Ni28 was born. Honestly, we first thought we were looking at wall art, but on closer look, you can see the fretboard and the soundhole are festooned with buttons.

Actually, they aren’t really buttons. The Ni in the name is because the buttons are nickel-plated brass plates that act like touch switches. There’s virtually no activation force required and you can easily touch more than one plate at a time.

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Balloon Guitar Is An Absolute Gas, Helium Or Not

May 14, 2022 by Lewin Day 10 Comments

Guitars are most typically built out of wood. Whether it’s an acoustic guitar with a big open cavity, or a solid-body electric, there’s generally a whole lot of wood used in the construction. However, [Mattias Krantz] shows us that alternative construction methods are entirely possible, by building his own balloon guitar.

The balloon guitar still has a neck, bridge, and strings just like any other. However, in place of the resonant cavity of an acoustic guitar, there is provision to install a large balloon instead. It’s actually quite interesting to watch — with the balloon installed, the guitar delivers much more volume than when played without a resonant cavity at all.

The guitar was actually built to test if swapping out air in the balloon for helium would shift the pitch of the sound. Of course, a guitar’s pitch comes from the tension on the vibrating strings, so changing the gas in the resonant cavity doesn’t directly affect it. Instead, much like inhaling helium to affect the human voice, the change is to the timbre of the sound, not the fundamental pitch itself. It sounds as if the guitar has been given a subtle treble boost.

It’s a fun build, and one that shows us that it’s possible to build musical instruments in many ways, not just using traditional techniques. If you want to further play with your guitar’s sound, though, consider turning to the world of machine learning.

Continue reading “Balloon Guitar Is An Absolute Gas, Helium Or Not” →

MiniDisc Player Supports Full Data Transfer

May 14, 2022 by Bryan Cockfield 28 Comments

Between the era of the CD and the eventual rise and domination of streaming music platforms, there was a limbo period of random MP3 players mixed in with the ubiquitous (and now officially discontinued) iPod. In certain areas, though, the digital music player of choice was the MiniDisc, a miniature re-writable CD player with some extra digital features. Among them was the ability to transfer music to the discs over USB, but they did not feature the ability to transfer the songs back to a computer. At least until now, thanks to this impressive hack from [asivery].

Although it sounds straightforward, this trick has a lot of moving parts that needed to come together just right. The MiniDisc player uses a proprietary encoding format called ATRAC, so a codec is needed for that. The MiniDisc player stores data from the disc in a 40-second buffer when playing, so the code reads the data directly from DRAM in 40-second chunks, moves the read head, repeats the process as needed, then stitches the 40-second parts back together. It can work on any Sony NetMD portable, if you are lucky enough to still have one around.

The project is a tremendous asset to the MiniDisc community, especially since the only way to recover data from a MiniDisc player prior to this was to use a specific version known as the RH-1. As [asivery] reports, used RH-1 players are going for incredibly high prices partially because of this feature. Since this new method demonstrates that it’s possible to do with other devices, perhaps its reign in the MiniDisc world will come to a close. For those still outside the loop on this esoteric piece of technology, take a look at this MiniDisc teardown.

Thanks to [Maarten] for the tip!