Skip to main content

Cavisynth SEQ-UFD Sequencer


Control Voltages, Please! 

My original idea was to control my synth with Ableton Live and MIDI but it turned out it's more fun to generate control signals with LFO's and other synth modules. The logical next step was of course a sequencer module. The Arduino based Cavisynth SEQ-UFD was the cheapest DIY project I could find and the specs looked good.

Sourcing Headaches and Jumper Wires, Part 2

This module build was pretty much a sequel to my Cavisynth Ardurack build. I had lots of problems with the required part types and ended up using all kinds of ugly hacks. With a small module like Ardurack I could live with that but the SEQ-UFD has so many jacks and pots that I just had to make another order to Cavisynth and get correct components before turning on my soldering iron.

SEQ-UFD consists of 3 PCB:s. It uses the same The Arduino Pro Mini processor module as the Ardurack.

Panel under construction

All PCB's are directly attached to the panel with jacks or pots. This caused issues because I originally used cheap Alps pots without panel fastening nuts. I had to change some of the pots to a different type to attach the PCB to panel.

Lots of wiring required. Luckily not as much as with the Ardurack module.

Two of the PCB's are connected with a flat cable. The third one required jumper wires.

Where's the Major Scale?

It's already a while since I built this module. First I was somewhat disappointed with it because it's difficult to get properly tuned notes out from it. There's no quantisation in the CV outputs so they can be used for experimental sequences but not for generating real melodies tuned up with other note sources. I eventually ended up buying a Korg SQ-1 sequencer which has the possibility to fix notes to minor or major scale. I really like the Korg sequencer and have been using that for my melody generation needs exclusively.

...who cares!

Luckily Cavisynth SEQ-UFD has lots of other features in addition to the basic note-cv generation possibilities. It contains individual gate outputs for every step. This makes it possible to use it as a clock divider or a simple drum sequencer. Lately I have used it a lot to drive all kinds of percussive things. The firmware also contains an alternative clock divider mode but I haven't had time to learn how it works yet.

Of course it's also possible to tweak the firmware. The generous amount of pots and jacks means this module has some serious hacking potential! If only I had more time...

Comments

Popular posts from this blog

Waldorf Blofeld Encoder Fix

Waldorf Blofeld is amazing little digital synth with almost endless possibilities. Unfortunately the rotary encoders seem to start skipping and failing sooner or later. After couple of years of light use my unit started failing too and it became very annoying to use.  First Try I first tried to open one encoder and clean it from inside. It worked ok but these components aren't really meant to be opened and closed again and I never managed to put it back together properly. Encoder shaft was loose and wobbly and it would have failed again soon because the encoder wasn't tightly closed. Proper Fix Luckily it's possible to fix it properly as long as you know how to solder. Current price for the full set of encoders is less than 7 euros. I ordered new Bourns encoders from Mouser: 1 pcs of  https://www.mouser.fi/ProductDetail/652-PEC16-4220FN0024  for the main encoder, this one has detents so it "clicks" when you turn it. 6 pcs of  https://www.mouser.fi/ProductDetail/65

Sunday Soldering: Akai Rhythm Wolf Drum Machine modifications

Sunday Soldering: Akai Rhythm Wolf Drum Machine modifications Akai Rhythm wolf is a cheap analog drum machine. It has a nice old school lo-fi sound but unfortunately Akai left out some quite useful features from the standard setup. Today I decided to modify my unit to better suit my needs. Here are the added mods: Added a resistor to the outer legs of the 'Howl' pot to make the range more useful. By default it's pretty much a switch between clean and a completely destroyed signal. I used 33k. Probably even smaller value would do. Added 3.5mm individual output jacks for all drums. The PCB has nicely marked spots where the individual signals are available but it's actually easier to take them from the volume potentiometers directly. The middle leg gives the signal after the potentiometer so volume also affects the individual outputs. It might have been a better idea to take it before the pot so that it would be possible to silence the signal from the main

Uraltone Mixer and Spring Reverb (and some synth literature...)

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