The same thing we do everyday, Pinky...

So, I like synthesizers.  They're buzzy, growly, quacky, chirpy fun.

Most look something like this:

Keys, switches, some knobs if you're lucky.  But back at the dawn of time the earth was ruled by gigantic, fearsome synthesizers like this:

They are called modular synthesizers.  It was thought for a time that they might be extinct, but healthy populations are starting to develop once again in a few parts of the world.  They allow musicians to connect groups of oscillators, filters, amplifiers, etc by hand to construct sounds electronically.  In addition to giving more sonic flexibility than their smaller descendents, they have the added virtue of looking like something from an evil scientist's lab.  Here's a picture of my own modular synthesizer, which was sick and neglected when I found it:

Sadly, no new modules have been made for my own modular system for about 30 years, so I've decided to make some of my own!  The problem is that my new ones sound nice, but look crappy.  Exhibit A:

To be fancy, I drew up a front panel in DIPtrace and placed an order with Dirt Cheap Dirty Boards. They finally arrived from Hong Kong today and they look good!

This is a generic front panel with a jack board and strip board that I'll use for a handful of different hand wired modules.  Here' a shot of the perforated boards before separation:

And here's everything put together for a quick fit check:

At 25 bucks for a run of ~10 boards (I received 12), I think it's a great deal!  If there are any other old PAiA enthusiasts out there looking to expand their old modulars, you can get a run of these here:
http://dirtypcbs.com/view.php?share=5031&accesskey=
The holes are drilled for potentiometers, 3.5mm jacks, and tip jacks like those found here:
http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=ebf6a654ea

Organ Donor

Everybody used to have an organ in their house.  It was kind of ridiculous.  I've written about this before.  As those things started to land in garage sales and thrift shops, though, people figured out some fun things to do with them.  They've got keyboards, tube amps, foot pedals, and bunches of other goodies just waiting to be re-purposed for cooler musical projects.

About ten years ago one such organ fell into my lap.  A move out of state meant I had to get rid of it, but not before I removed a rotary speaker cabinet out of it.  Back before the reign of the transistor, it was easier to add effects to musical instruments with motors and baffles than with extra gain stages, and practical real time digital signal processing was beyond everyone's wildest dreams.

This Leslie speaker has a 6-8" speaker behind a large styrofoam baffle that spins in front of it, changing the direction of reflection.  It adds a tremolo (amplitude modulation) and a bit of vibrato (pitch modulation).  I use a light switch to turn on the single phase motor which spins the baffle.  I'm a bit embarrassed, but I was done with engineering school before I learned about using diodes or RC filters to suppress (snub) switching transients on motors and solenoid coils.  I've added a little board with an RC snubber to the speaker to eliminate that loud electromagnetic interference pops that occur when I switch off the motor otherwise.  Here's the little board that I made up for the snubber:

It's a series resistor (240 ohm) and capacitor (0.05 microfarad) in parallel with the motor to give the transients a path to ground after the switch is opened.  A schematic may be overkill, but here it is:

Here's a little video to demonstrate how the speaker sounds:

Sugar and spice

For long periods of time the kids will largely ignore all the weird stuff in Dad's room.  Then at other times they'll get curious about the instruments and equipment that I use.  The other day Lucy (age 3) wandered in while I was playing guitar and announced that she wanted to record a song.  This is a recording of me playing along to one of her improvised songs.  Josh wandered back and forth in front of the mic as we recorded, contributing rubbing and shuffling sounds.  The bang as something hits a guitar body at the end was him, too.

Lucy will sing alone as she plays or occasionally to me at bedtime, but I think this is the first time I got a decent recording of one.  After we finished, I got out the headphones and said, "Okay, do you want to hear it now?".  To which she answered, "Nope!".  Then she skipped off to play a different game.

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!

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":

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:
https://github.com/thecowgoesmoo/AnubisArray

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

Goldcrush

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.