Today’s late-night puredata madness: creating a 7-limit just intonation abstraction which takes standard 12TET MIDI note numbers and spits the 7-limit just version, expressed as a decimal MIDI note number:
Today’s late-night puredata madness: creating a 7-limit just intonation abstraction which takes standard 12TET MIDI note numbers and spits the 7-limit just version, expressed as a decimal MIDI note number:
Talking of [filterview] (gh), here’s the abstraction I made for it, incorporating stereo smooth filters and a nice mode switching UI made of a [hslider] hidden behind a bunch of canvases.
Each canvas has a receive ID of $0- plus the symbol for the relevant filter mode, making the message sending for changing the colours easy.
[biquad~] clicks and pops when changing coefficients, which is annoying when they’re coming from the [filterview] UI. The best way I found of smoothing them was to alternate between two biquad~ objects and crossfade between them over 3ms. This approach, while a little cludgy, is probably generalisable to a lot of similar Pd situations where smooth transitions are desirable.
Their website vectortours.de is one of the most confusing I’ve ever seen. A German domain with a weird mixture of Albanian and German text. Most of the phone numbers don’t work, and when I tried calling the German number and asked in German about their lines from Macedonia to Montenegro, they were dumbfounded and had no idea what I was talking about. Some of the ticket desks in Skopje firmly denied the existence of the company, until we eventually found one who gave us a ticket. Then, by chance, we ended up staying in a hostel in Prizren which was literally next door to the Vector Tours office, which was adorned with three completely different logos! I think some other weird stuff happened which I forgot, but in total this was enough to cement them as a semi-legendary entity and permanent in-joke.
Some tips for building a Mutable Instruments Ambika, based on my experiences:
Based on the part numbers in the BOM, suppliers will sometimes pick a CD4050 chip. These are not fast enough and will cause SD card access to fail, it’s necessary to use a 74HC4050.
If you’re using a 74HC4050 and SD card access is still failing, check whether communication with all of the voicecards works. I had a lot of issues where failing or badly connected voicecards would interfere with the serial lines and prevent SD card access from working.
On that note: shell out on good quality stacking headers for the voicecards. I picked cheap ones, and suffered a long series of hard-to-debug issues caused by them not reliably connecting. I ended up having to coat all of their legs in solder to make them thick enough to reliably connect. Good headers are worth the premium to avoid these headaches.
The 3.3V regulator, DACs and all the MCUs can be obtained free from the Microchip samples service if you’re willing to do it over a few months in limited quantities of two part numbers at a time.
My Pololu USB AVR Programmer wasn’t able to provide enough power whilst programming, so I had to power the boards for programming. For the voicecards, having both 6 pin headers connected interfered with programming because of data being sent to the voicecards over the serial lines. I ended up powering up the motherboard, placing a stackable connector in the power/audio socket voicecard socket and plugging the voicecard into that for flashing, so that it’s powered but the serial lines are disconnected.
I programmed my Ambika with the YAM firmware to get those smooth sounding PolyBlep square and saw waves. I built the firmware myself, downloading CrossPack 2010-01-15 which provides avr-gcc 4.3.3, the correct version for compiling most old MI AVR firmwares.
I would recommend buying higher quality pots and encoder with metal shafts rather than the flimsy plastic ones in the BOMs. There are so few on the Ambika that the added expense is only a few euros in total. An Ambika is such a large time and financial investment that there’s really no reason to use flimsy, wobbly plastic pots.
I got my PCBs from the Pusherman group-buy, they‘re very cheap and work fine.
I built an Ambika to join my family of Walnut Mutables!
I messed up the LED holes in this one, but the laser engraved front panel graphics and text came out really well. The back panel is acrylic so I can admire my electronics handiwork and Emilie’s amazing design any time.
I took the opportunity to give my Shruthi a knob upgrade, too.
and here’s @briansuda’s translated hieroglyph version! https://optional.is/required/2009/12/03/welcome-the-entire-land/
@BurntToast_DFIR fantastic, thanks! Any idea where I can get a copy of the CD?
EDIT: I found it, the website is a bit labyrinthine.
Dramatic happenings at the mill last night! A huge dead tree fell over the bridge, causing a minor earthquake. Nobody hurt apart from a fence (which fortunately doesn’t even belong to us)