noise embedded.

SMD Soldering for Real! As I mentioned in my earlier post  I'm currently trying to learn SMD soldering. After successfully completing two dummy practice boards it was time to try a real project. I had ordered four Mutable Instruments clone boards from  https://www.amazingsynth.com/  and Ripples was the easiest so it became the first victim. Sourcing the Components Sourcing SMD parts is all new to me. Capacitors have all kinds of weird material codes, resistors have unfamiliar wattages etc. Luckily amazingsynth.com provides mouser BOMs so you get almost all parts to the shopping cart with a click or two. I will eventually get familiar with SMD parts but at this stage I'd rather not add any more difficulty to the build by ordering wrong components.  Unfortunately potentiometers are not included and jacks need to be ordered elsewhere. I happened to have plenty of thonkiconn jacks from Thonk  and also some potentiometers. Unfortunately it later turned out...

DIY kits and literature Bjooks and DIY kits Every now and then I had seen pictures of the beautiful and super interesting Push Turn Move book by Kim Bjørn:  https://www.pushturnmove.com/ . Unfortunately it's not available as an eBook and the price has been too high for me because of the shipping costs. Some time ago Bjørn launched the Kickstarter campaign for his third book Pedal Crush . All the buzz it generated in social media led me once again to the Push Turn Move web page. This time I was delighted to find our local DIY music electronics store Uraltone in the reseller list. Of course I had to buy both of the already published "Bjooks" immediately and while at it I decided to buy some Uraltone eurorack DIY kits too. I have wanted a spring reverb since the days I got my first electric guitar and another mixer in my eurorack wouldn't harm. After a short bike ride to Uraltone I had my back bag full of reading and soldering! Support your local! Uralkit Spring...

Midi Moose. Midi Issues Everywhere After finalizing the Acid Moose 303 clone build my midi usage increased significantly. So did my midi problems. Unfortunately I just couldn't get the Acid Moose midi interface working reliably. Sending too many messages made it freeze and the whole device had to be rebooted. I tried changing opto-isolators, crystals, pretty much everything around the pic microcontroller but nothing helped. Anything more than simple note on and note off messages would make it fail. Unfortunately that midi implementation is significant part of the sound because it mimics many 303 peculiarities so changing to another microcontroller implementation wasn't an option either. Needless to say the source code is not available. I finally gave up debugging it and decided to add a midi filter in front of it to throw out everything except the bare minumum of needed midi note messages. Around the same time I also bought an Elektron Digitakt sequencer/sampler. ...

Surface Mount Future It's time to face the truth. Nobody uses good old through hole components for professional electronics designs nowadays. This of course means that there's less demand for components and more and more new components are only offered in surface mount form factor. Sooner or later hobbyists need to follow the trend and start using SMD components too. I have been avoiding SMD projects without any good reason. I've seen how easily hardware designers at work solder all those tiny barely visible components but somehow thought it would be too difficult to be fun. And I don't want to waste my scarce free time doing something that I don't enjoy! I have Mutable Instruments Clouds module in my eurorack and have always liked the open source approach they have. I have been aware that many people build their own DIY versions of those brilliant modules but have always skipped those projects because of the SMD soldering. After giving it some thought ...

Modular Drum Machine? It was yet another boring afternoon at work. I ended up searching for some interesting DIY eurorack kits. I had never considered adding any drum stuff to my modular synth. I have the not so perfect Akai Howling Wolf drum machine in my setup and have been somewhat disappointed with the kick drum of the unit. So when I found the cheap  Sound Force 808 kick diy kit  I just couldn't resist. They also have 808 snare kit available so of course I had to get both. Weird-Valued Vertical Resistors I usually start all pcb builds by soldering the resistors. They are easy to install and are the lowest components. Unfortunately these boards are designed for smaller resistor components. They can be built with normal through-hole resistors but everything needs to be installed vertically. This makes soldering much slower and more painful. I have plenty of resistors and capacitors around and these boards don't use any exotic ICs so I thought I could build th...

The Very Beginning of the Signal Chain Voltage controller oscillators, or VCO's, are the root of everything in subtractive synthesis. That's the place where the sound is born and everything after that is just modifying it. VCO really creates the sound. It is also the component that defines pitch and thus makes melody and harmony possible. Rest of the signal path is mostly about timbre. (And rhythm of course.) I started my modular synth by building a Doeper DIY Synth so I only had one VCO. It really limited things so I had to get more. Things got a bit better when I added another Doepfer DIY Synth to the rack but 2 oscillators is still not that much. There's two reasons to add more oscillators. First one is to be able to play multiple notes at the same time to generate harmony. The second one is to configure multiple oscillators to play the same note to generate more complex sounds. Analog VCO's are always more or less out of tune so the sound will get thick...