Thursday, December 18, 2014

Christmas Music

There are about 10 Christmas songs that we here over and over.  "Joy to the World", "Silent Night", "We Wish You a Merry Christmas"... you know the ones.  Arrangers bend over backwards to try to find a new angle for "O Come All Ye Faithful" in their marching band/solo piano/pop single arrangements.  Kids sing them at school concerts.  They're in the background on radio ads.  They're belted out by pop stars to try to re-start stalling music careers.   By December 26, though, you're likely to get expired eggnog chucked at you if you start singing "Jingle Bells".

The secret is: there are other Christmas songs.  My friend Jenny picked out several that I hadn't heard before for us to play at a church party recently.  It was so much fun that we decided to record a few of them.  This is "Rise Up, Shepherds, and Follow".  It's Mallory Nuzman singing with Jenny Webb on piano and myself on bass.  Merry Christmas!

Sunday, November 16, 2014

Last Christmas

It's that time of year when all of the pop Christmas songs from the last bazillion years get radio play once again.  Strangely, it's seems like a performer's best shot at getting more than a few months of radio play out of a single is to put out a Christmas song, because the competition isn't as stiff and they get played every year.

They seem to range from classic big band and rockabilly stuff, to folksy shame-on-you-for-being-happy-during-Christmas stuff, to just plain weird stuff.  The song I picked is probably closest to the last category.  Before George Michael tossed aside Wham! like an old dirty rag, they recorded a Christmas song: "Last Christmas", a strangely smooth post-Christmas breakup song.

Personally, I think that breakup songs should be disastrous, petty, pleading things like Ben Fold's "Song for the Dumped" (warning: explicit) and Cee Lo Green's "Forget You", so I decided to record my own version of "Last Christmas":

Friday, September 26, 2014

Anubis guitar preamp

So, on electric guitars there are usually 2 or 3 pickups placed along the string.  You use switches to select which ones to use and the resulting sound depends on the pickup placement relative to the nodes and anti-nodes of the strings.

Some people get adventurous and drill holes in the guitars to add switches or knobs to allow for more control than the stock wiring affords.  I decided to make a preamp that would allow any combination and polarity of the pickups (even time-varying ones) without requiring modifications to the guitar's body or pick guard.

And so, the Anubis preamp for Fender/Squier Stratocasters was born!  There's a digital potentiometer and polarity switch for each of the three pickups.  They're all controlled by a microcontroller.  The control software can be edited and uploaded to the Anubis with an Arduino UNO board.

The volume and tone potentiometers have been replaced with a program selection encoder and two program value potentiometers.  Here's a shot of the boards.  The minimum order from the board house was 10 units, so I have some extras :)

And here's the board populated and installed on my Strat's pickguard.  There's a single IDC breakout cable that goes from a header on the board to the switching jack, the pickups, the battery, and the programming cable.

I've made a mostly dry recording of the guitar (direct injected, a little compression and reverb added) to demonstrate a few of the programs I've written for it so far.  In the order of recording they are:

1. Sample and hold: abruptly switching between randomly selected pickups.
2. Fast chorus: The pickups are amplitude modulated with low frequency sine waves that are 120 degrees out of phase with each other.  Sounds kind of like a three tap chorus.
3. Slow chorus: same as above, but with a slower modulation frequency.
4. Some of the 13 different pickup combination and polarity options. 

If I have time to do it over, I may try nice VCAs (like the  SSM2164) instead of digital potentiometers to avoid the annoying stepping/zipper noise. 

Here's a link to the GitHub repository for the microcontroller's software:

As promised, here's the schematic:

And here's the bill of materials:

Description mouser part number unit price quantity line total number on board
Switching jack 502-113X 3.15 1 3.15
IDC plug 617-09-18-520-7803 2.06 1 2.06
IDC header 571-7-146256-0 3.81 1 3.81
Amphenol flat cables 523-135-2801-020FT 1.75 1 1.75
Potentiometer 311-1901F-10K 2.87 2 5.74
Rotary encoder 652-PEC11L4125KN0020 1.43 1 1.43
7805 regulator 595-UA7805CKTTR 0.767 1 0.767 U8
regulator capacitors 77-VJ1206Y334KXJTBC 0.08 4 0.32 C13, C14, C15, C16
decoupling capacitors 77-VJ1206Y104KXJPBC 0.033 5 0.165 C7, C8, C12, C17, C11
output capacitor 77-VJ1206Y332KXJPBC 0.06 1 0.06 C1
crystal capacitors 77-VJ1206A220KXACBC 0.05 2 0.1 C9, C10
pull down resistors 652-CRT1206BY1002ELF 0.31 2 0.62 R8, R9
diodes 696-SML-LX1206YC-TR1 0.1 2 0.2 D3, D4
16 MHz crystal 774-ATS160SM-1 0.24 1 0.24 Y2
power supply resistors 71-CRCW1206J-100-E3 0.03 2 0.06 R10, R11
AD5222 584-AD5222BRZ1M 2.02 2 4.04 U2, U3
DG403 968-DG403DYZ 1.43 3 4.29 U4, U5, U6
9V battery holder 12BH610-GR 1.05 1 1.05
Atmega328 556-ATMEGA328-AU 2.58 1 2.58 U1

Saturday, July 26, 2014


My friends Matt and Treesa Gold play in an amazing band called Goldrush.  Last week I got to hear them live for the first time, which was a real treat.  They're sound isn't what you'd expect to get from a double bass, violin, guitar, and drum set.  Prabir's songwriting is intelligent and playful.  The guitar work is very good, but understated,  giving plenty of space for the violin and double bass.  The resulting voicing is more sparse than I'm used to, making the actual chords and movements between them less obvious than normal, like some tantalizing harmonic strip-tease.  But when I say "sparse" and "understated", don't think I mean "delicate".  As they play, they control you.  They'll kick you around and you'll like it.

Here's a link to iTunes where you can get their first album, "Greatest Hits".  You're a good person.  You deserve to have their music in your life.  And here's a picture of them doing their thing:

Just like after any good show, I returned home wanting to play.  I started on a cover of their song "The Exit Song", using a very different instrumentation from the original, but the project proved too ambitious for the time I had and I got less than a minute's worth done.  It was fun, though, so I'm posting it anyway.  I made it using a tack piano (piano with metal thumb tacks in the hammers), Hammond organ, fretless electric bass, ukulele, lap steel guitar, cracklebox (one of these things), Shruthi-1 synthesizer, tambourines, and a wooden plank that I slapped with my hands, since I don't have any drums. 

Sunday, April 20, 2014

Wire organ

In the late sixties, Wendy Carlos released an album of Bach music played only on a large Moog modular synthesizer.  Modular synthesizers were large panels of separate electronic modules (oscillators, filters, etc) that could be connected together to produce sounds.  Here's a picture of one:

It was really all just electronics lab equipment tweaked a bit for sound production.  Electronic music was a child of recording technology.  Once it was possible to convert sounds to electrical signals for storage later, it was only a matter of time before someone would try to make sounds starting with just the electronic signals.  Here's a link to Wendy Carlos' version of Bach's Brandenburg Concerto No. 3:

While it seemed shocking to some music aficionados at the time, it was a pretty natural use of the synthesizer.  Bach had written a huge body of work for the organ, and the pipe organ is very much like the synthesizer.  It's got different ranks of pipes made from different materials in different shapes to mimic orchestral instruments.  The names of the pipe styles even come from the German names for the different instruments that they mimic.  I recently built a single-voice synthesizer from a kit designed by mutable instruments.  Here's a picture of the Shruthi-1:

It's not nearly as imposing as the Moog modular, but it's still a lot of fun.  Here's a recording I made of a Walczynski organ prelude that I mad on my Shruthi-1:

Wednesday, February 12, 2014

In other news...

This post doesn't really fit on the blog, but I don't have a better place to post it and some other DIYer out there may want to do something similar.

My wife inherited a nice Evenheat glass fusing kiln.  The only problem was that the 20-year-old temperature controller wasn't working.  After finding the manual for it online, she decided that she wanted something more flexible and user-friendly anyway.  I convinced her that it would be relatively simple and inexpensive to build a better temperature controller from scratch.  A replacement controller was available from the manufacturer and other compatible controllers are likely available, but it seemed like a good excuse to play with an Arduino board. 

After more time than I'm willing to admit, it's up and running!  Behold the Meltinator 9000:

And here's the obligatory cheeky initialization screen:

The kiln controller uses:
-an Arduino Uno board
-an Adafruit Arduino display shield
-an Adafruit protoshield
-a K-type thermocouple reader board (MAX31855 based)
-a resistor, BJT, and diode to drive the relays

Schematics would be overkill for this one.  The circuit to drive the relay was like the version linked below, but with the resistor value adjusted for the resistance of my relay coils.

Luckily, the new kiln controller fits nicely in the old enclosure.  That made life a lot easier.  Flipping through 19 bazillion pages of a Mouser catalogue to find the right enclosure and switch caps is no fun.

The software allows for 25 different fusing schedules to be programmed.  Each schedule has 10 steps.  Each step has a target temperature, a temperature rate of change, and a hold time.  The user can add time to the hold cycle of the current step during execution of a schedule, if needed. 

The software for the kiln controller can be found at github here.  Use at your own risk.

I ran a two-step test program earlier today and kept an eye on it to make sure the house didn't burn down.  First, it ramped up to 1500 degrees Farenheit at a rate of 2550 degrees per hour.  Then it cooled down to 500 degrees at a rate of 1000 degrees per hour.  Heat-up worked just as planned.  Cool down was slower than anticipated; the kiln is better insulated than I had thought.  I may need to prop the kiln lid open slightly during cooling if I want the controller to be able to control cool down accurately. 

To wrap things up, here's a picture of some of the stuff that Sarah makes in the kilns.  She's gotten really good!