Fan Noise Synth

On a recent trip abroad the wife and I ended up taking an overnight trip for two days & nights and needed to drown out some of the noise at the place we were staying. At home we use the Sleepy Noise Machine which actually plays an audio file of a fan running to create some white noise. We don’t travel with the machine though, so my first thought was to use my iPad to play one of those 10 hour long YouTube videos of a fan running…

Problem 1. The hotel said “Free WiFi” which, you know, there was, but it was not actually connected to the Internet. Whoops. Problem 2. I could have tethered my iPad to my phone for Internet access but since we were traveling abroad the slow data rate and roaming data make that a bad idea. So…

I fired up AudioKit Synth One, screwed around with customizing a square wave, set it to hold the note, and pressed a few keys to get a (satisfying?) imitation fan noise, which you can hear in the video below.

I think I’ll probably just load some suitable audio files onto the iPad before the next trip abroad just to be safe, but I was pleased I came up with a solution when needed.

(When playing the video below you might think “That sounds nothing like a fan!” and, it sort of doesn’t, but trust me, in a hotel room where you want to drown out the noise from the next room… it’s close enough!)


Adafruit NeoTrellis M4 808 Drum Machine

A while back (umm, last year?) old pal Kirby gave me an Adafruit NeoTrellis M4 with Enclosure and Buttons Kit Pack which I believe he got in an Adabox. At the time I was like, “Hey, this is neat!” and put it aside because I was busy with work. Well, I finally found it when I was cleaning the office and decided to dig a little deeper and discovered the demo code it shipped with was already running a minimal drum machine! They had some samples loaded up and it was a super-basic tracker. Fun!

The provided samples were not that great so I grabbed a kick, tom, snare, and hi-hat from the classic Roland TR-808 which, well, you probably know. As for the Adafruit NeoTrellis, it’s is a fun little drum machine! A bit challenging, and definitely minimal, but worth spending some time with. The audio is running out of the NeoTrellis and through a Bastl Dude and filmed/recorded to an iPhone.

Note: I found this guide to Trellis M4 Beat Sequencers which should prove extremely useful! It’s way more capable than I imagined, which shouldn’t be surprising since it’s from Adafruit.


Sync a Behringer TD-3 to a Pocket Operator

Last year I wrote up Syncing a Behringer RD-6 to a Pocket Operator via a Pi Pico which was more of a “wow, this works!” thing than a good explanation. I say that because a few people thought it was nice, but didn’t quite understand it, or wanted a diagram, so here’s a diagram…

The 1/8″ stereo jack on the left is where you plug in the Pocket Operator, and the 1/8″ stereo jack on the right goes to the device you want to sync up. (A Behringer RD-6 or TD-3 for example.) The ring/red is the audio side of things, the tip/orange is the click/sync signal put out by the PO, and sleeve/black is the common ground.

As previously mentioned, the Pocket Operators are awesome, and they can sync with each other, but can’t always sync with other devices. They put out a 1 volt signal for the sync track (the “click”) and most other electronic devices want something higher, like 2.5 volts, or 5 volts. The Behringer RD-6 wants over 2.5 volts, so you cannot sync it to a Pocket Operator, but now you can with this device!

This basically reads the 1 volt from the Pocket Operator, and then outputs 5 volts that the Behringer RD-6 can recognize as a sync in signal. While the RD-6 has a sync out port, there are reasons you may want to have the PO be the primary and the RD-6 be the secondary. There’s also the Behringer TD-3, which (oddly enough) does not have a sync out port.

A guy named Oscar got in touch and asked if this worked with the TD-3 and at the time I didn’t have one. Well, I have one now, and it works great. And since the TD-3 does not have a sync out port (!?!?) this is the only way (without additional hardware) to sync a TD-3 to a PO.

I built one (using a Nano, not an Uno) and I’m sending it to Oscar to test out. He’ll need to provide a USB power source and a splitter cable to get it working. (He’s got both already. Most Pocket Operator nerds probably do.)

I did make one mistake on this device… I actually incorporated labels into the enclosure. I for “In” and O for “Out” and when assembling it I didn’t notice I had it backwards until testing. Oops! So I just stuck some labels on the top, and now In is on the right and Out is on the left. If I make another, I’ll do it right next time. Oh, I also realized I could probably just build a splitter into it by adding another jack, so I may do that as well. (Though that will increase the size of the enclosure a bit.)


Korg NTS-1 Preventative Maintenance

The Korg NTS-1 is a $99 digital synthesizer and effects box that is just straight-up awesome. It’s cheap, but packed with features, including the ability to load custom oscillators and effects, and there are a bunch of them out there for free and for a price. I’ve had a blast making noise with this thing, and there are a few groups online for discussion of the NTS-1.

The NTS-1 is a kit you build yourself. Don’t worry, it just requires a screwdriver (which is included) and it’s really just assembling the enclosure around two circuit boards. Takes about 15 minutes if you go slow. Where the NTS-1 does not shine is in its durability. This is not a device you just toss into your bag, or that can easily travel to a gig. It is… fragile. The main fragility (as many will attest to) is in the connectors. So I’ve tried to strengthen them a bit.

I started by taking the unit apart. Well, just removing the top panel and top PCB. The rest of the pieces of the enclosure can stay put together.

The 1/8″ jacks are soldered on as surface mount components. This is pretty terrible, as they really should be through hole components to help provide a solid mechanical connection to the PCB. I’m sure it was done this way to keep things cheap. The problem is that if the jack pulls off the board it will probably pull off the solder pad as well, so you can’t really replace it. Sigh. I added a bunch of hot glue around the headphone jack. Some have questioned if this will do anything. I figure it’s better than nothing.

Here’s the same treatment to the other jacks. (MIDI in, sync in & out, and audio in.) Just lots of hot glue. Basically the more you plug and unplug things with these jacks the more stress they’ll be under. I’ve seen at least one person build a larger case around their NTS-1 and then use panel mount plugs so they aren’t repeatedly plugging and unplugging from the jacks on the unit. It’s a good solution but does increase the size of the unit.

I also added a laser cut overlay panel to mine. (Mostly cosmetic, though it does keep the top surface a bit cleaner.) I did have to grab some longer screws to hold it in place. If I remember correctly they were 2.5mm machine screws about 8mm long. (The stock ones were a bit too short to catch enough of the threads due to the increased height caused by the overlay.)

The file I used was just a slightly modified version of one that Korg provided. Since black and green are two of my favorite colors this looks great in my opinion.

Oh, one thing I forgot to do was put hot glue all over the Micro USB jack! I will need to open it up and add more glue to that.

Here’s a little sound demo of the Korg NTS-1 which has a built-in arpeggiator.


EGDR606 Drum Machine

While I’ve been doing this DAWless thing and avoiding using computers for music making I haven’t completely moved away from what might be called “computer music”. I was exploring iOS music applications and found the EGDR606 Drum Machine which was $3.99 USD.

It’s a recreation of the Roland TR-606 which means it’s similar to the Behringer RD-6 Analog Drum Machine I use. For that reason I gave it a try. While I would rather use the RD-6 every time, while on the move the EGDR606 can be a fun little thing to play with. Occasionally I’ll make some drum pattern than I can then try out on my RD-6, which is nice.

You can find a nice review on or check out the PDF manual.

I did find the application a little rough as far as saving out patterns, but it it can export WAV files and you can grab them to move elsewhere. Honestly that’s probably due in part to the clunkiness of the iOS file system, so it’s not a huge deal. It could just be a bit cleaner.

(If you’re more of an 808 fan you can check out the EGDR808 from Elliot Garage instead.)