Line Filters and OP-Z Earth Loop Noise

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When I was much younger, and vinyl records were a thing, I used to have a problem with earth loops between the turntable and the amplifier. The problem was that both the turntable and the amplifier were connected to the electrical earth for health reasons (my health not theirs). Then, when you connect a cable to send the signal from the turntable to the amplifier you add a second ground connection which causes induced noise. You had to fiddle around with the earth signals to get rid of it.

Fast forward to today and I’m connecting my OP-Z to my computer using the audio and usb inputs at the same time. Which makes another ground loop and more noise. There is a way that you can try to address this by turning off the USB charging on the OP-Z (Press [Screen] + Keyboard (E) - Spark) but this limits how long you can play with it and doesn’t always work. Instead I’ve got hold of a ground loop isolator which contains a tiny transformer that electrically isolates the input from the output. It reduces the level a bit, but it also makes all the nasty noise go away, which is what I want.

Great book for the Teenage Engineering OP-Z

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There are some great videos about the Teenage Engineering OP-Z synthesizer. I can strongly recommend ones from Cuckoo. However, I rather like having a proper book to look at. And that’s where SynthDawg come in. They’ve written some lovely books, including an OP-Z one. Their prices are very reasonable, the books are supplied as pdf documents that you can read on any device or print out if you fancy real old school bookery.

GameGo looks like fun and games

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Derek put me onto this. It’s a GameGo. Underneath the rubberised case is a little device that can run JavaScript games written using the Microsoft MakeCode framework. There’s a rather nice particle demo that you can see running above. The device is a great way to entice people into game coding as it is a properly portable toy that you can fill up with your own creations. I’m looking forwards to having time to play with it.

Teenage Engineering OP-Z

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The Teenage Engineering OP-Z is an amazing little device. In around the same space as a remote control (see above) it packs in a bunch of synthesizers, a sequencer, a sampler, a DMX lighting controller and and a 3D video controller that talks to Unity. You can use it as a midi host or client, plug it into your PC and add samples and pull back recordings of pieces you have stored or just listen through the tiny speaker. It’s battery powered, so you can write tunes on the bus if you wish. In my case that might even help with social distancing….

There is no display. You can use a phone or tablet to see what it is doing, but the coloured leds in the buttons means that once you get your head around the fundamentals it isn’t too hard to see what is going on, especially if you have a programming bent. I’m not sure if its cleverness can compensate for a lack of musical talent, but I’m having a lot of fun trying to bash out silly tunes with it.

Expensive family trip

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We actually managed to go out today and visit family members. Very strange. Everything is still there, but most of it is shut. It was rather like driving round the latest version of Forza Horizons which includes some places I’ve actually been to. In the game you can see shops, offices and buildings that you can’t go into. Just like today.

Anyhoo, we had a socially distanced gathering which was so much fun that I forgot to sell my turnips in Animal Crossing. They go rotten tomorrow. Oh well. Totally worth it.

Online banking in actually quite good shock

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Today I had some banking duties to perform. I had to change the contact details for an account. I was a bit worried about doing it. These kinds of escapades usually involve a trip to the bank, standing in a queue and then waving around lots of bits of paper. This was an especially unattractive proposition in the current situation, particularly as the local branch is presently shut.

Anyhoo, after a bit of fun and games with a little keypad thingy that I’d been sent a while back I managed to get it all sorted via my phone. I love it when things just work.

New Technology Paper Review

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In the olden days I used to get up specially early, drive up town and review the papers with Radio Humberside. Nowadays I get up at the usual time, stagger over to my computer, put on my headphones and connect to them. I’ve just done that. The station has upgraded their on-line act so that we can now converse over Skype rather than the phone and it sounds rather like I’m in the studio.

Anyhoo, it was great fun and thanks for inviting me.

M5 Atom and Tailbat

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The M5 Atom is a neat little ESP32 based device. They now do a version with 25 multi-coloured leds on it which is rather nice. You can also get a battery pack with the wonderful name of the “Tailbat” to plug into it and keep it going. You can program the device in Arduino C++, use MicroPython or even the UiFlow block based environment, all over the air from a browser.

Great fun and loads of potential.

Making high dynamic range pictures from one photograph

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I’ve always liked making High Dynamic Range photographs. These are created by merging several different pictures with different exposures. The idea is that the combined picture has a great range of light and dark. However, making the images can be a bit of a pain. You have to take three or more shots and then use a program to combine them. And if things in the picture move, for example a tree blown by the wind, you can get some annoying artefacts.

So yesterday I tried a simpler approach. I deliberately under exposed each picture to make sure that I captured the sky detail and then made the dark parts of the picture lighter using Lightroom. I’m quite pleased with the results.