karmapod

Several criteria guided the design of the Pod as I moved from the initial concept, to the frantic writing down of ideas, to a detailed budget spreadsheet, and finally to the purchase of parts and assembly of the final product.

At the time I built the Pod, the Athlon64 had only recently been introduced, and there were great deals available on Athlon XP hardware. I chose a SOYO Dragon II motherboard, 1 gigabyte of memory modules recommended by SOYO, and an AMD Athlon XP 3200 CPU. In retrospect the system might have longer life had I gone with an Athlon 64, but in truth, I haven't begun to tax the CPU power of the Pod even in complex recording situations.

After a great deal of deliberation I settled on the R908U20 Roto Shock Rack Case from SKB Corporation, manufacturers of a wide variety of protective cases for everything from guitars to guns. I paid over US $400 for it, but as this protects a significant hardware investment mounted inside, it's quite worth the money.

At 8 rack units high and with rack mounts in both front and rear, this puppy is more than big enough to mount a full-size server PC chassis, audio interface, power conditioner, and patch bay—and that leaves a unit to spare! The case also includes tightly-locking rubber-sealed lids to prevent water getting in during transport. They even included a set of nice black rackmount screws with matching washers.

The PC chassis took some time to select. Most rackmount PC cases are meant for server use, and are thus quite ugly because nobody will ever look at them. I finally found a sleek, black 4-unit-high chassis from Athena Power corporation.

This is just about the sturdiest and roomiest PC case I have ever handled, and probably the last I will buy for years. It's got a great-looking front panel, lockable swinging front doors, along with six full 5.25" and two 3.5" disk drive bays. Considering that I needed to install three hard drives and two DVD drives, this was more than enough and left room for future expansion.

One drawback: the chassis is quite heavy even without components installed, and it became necessary to buy a pair of Chatsworth equipment support brackets (see Chatsworth.com) to support the weight of the completed PC's rear half. These are a specialty product and I had to hunt for them, eventually finding a supplier in Graybar Telecom of Somerville, Massachusetts.

I chose a Seagate 80GB 7200RPM ATA/133 hard disk drive to store the operating system, applications, and home directories.

For audio files, I purchased two Seagate 200GB ATA/133 hard disk drives and installed them as a RAID-1 array, with the same data always stored on both drives. Not only does this help prevent data loss if a drive dies, but it also improves reading speed because the system can read simultaneously from both disks. Think of multitrack recording, where many tracks are being played back into monitor headphones while the vocal part is being recorded.

I purchased two DVD drives from LITE-ON corporation— one high-speed reader for ripping discs, and one dual-layer burner for creating mixdown CD's, DVD backups, and video DVD's.

Of course, an audio workstation PC is only as good as its audio input and output devices. Due to the state of driver support on Linux, one must choose carefully.

For a recording studio, all bets are off if the audio workstation sounds like a vaccuum cleaner. I took great pains to get the Pod's running noise level down to an absolute minimum.

First, I replaced all the fans with ultra-quiet models from Zalman. They make a great "flower-shape" CPU cooler that makes virtually no noise when running at its lower speeds.

Second, I bought three CoolerMaster CoolDrive units, which cool and muffle the hard drives. One of them is also a 4-way fan controller and temperature monitor, wired up to all the fans in the system. In this way I can run the fans at the lowest possible speed while monitoring temperature safety. As usual, these fit into the black-and-silver color scheme I'd been developing for the whole system.

These were attached to the drive bay housings with rubber washers to help stop disk vibration noise transmitting to the case itself.

Third, I chose an ultra-quiet Coolmax 550-watt ATX power supply with a controllable fan. When set to its lowest speed, this power supply is virtually inaudible.

Finally, I lined the entire PC chassis interior with PAXmate adhesive noise insulation foam to quiet any remaining sound.

As a result, the machine is almost completely silent when the front bay doors are closed.

I bought a Raxxess PD-800L rackmount power distribution unit. This is basically a rackmount surge protector and power strip, with plenty of wide-spaced grounded outlets on the back, and one on the front. The unit also has retractable lights on a dimmer switch, which can be used to light up your work area during a gig at a club (where the lighting situation is often less than optimal.)

I decided to buy the M-Audio Keystation Pro 88 MIDI Controller almost as soon as I felt its keys in the store. I was taught to play piano on rather stiff weighted keys, and can't stand the springy keys of a synth. The Keystation has quite heavy action and I couldn't resist buying it. It can also be powered via its USB connection, alleviating the need for a separate power cord.

Furthermore, it's got plenty of assignable general-purpose knobs and buttons, offering the prospect of immediate tactile control over audio software.

And now for one of the finest keyboard/mouse combos available, the Logitech DiNovo Wireless Desktop. The keyboard is ultra-slim and has laptop-like keys (but a decidedly desktop-esque full layout.) Crucial for a recording studio, the keyboard is also very quiet while typing at normal speeds.

At a local antique shop, I found a great set of chairs for the musicians to sit in. They're from the sixties and made of yellow vinyl—the exact same yellow as the cones on the KRK monitors! It was US $35 for the pair. The chairs are armless, perfect for holding a guitar while seated.

The good news is that there's a great shortcut in setting up your machine. The folks at Stanford University's CCRMA have already done much of the hard work of configuring Fedora for audio workstation use. They run a sort of "meta-distribution" that installs on top of Fedora Core, called PlanetCCRMA (pronounced "planet karma".) This work saves so much time and effort that I decided to informally name the Pod after it, sometimes calling such a machine a "KarmaPod".

PlanetCCRMA installs an enhanced low-latency Linux kernel, updated ALSA drivers, and loads of high-quality audio and video applications. There is a vast amount to explore here, and it's all much easier than installing and configuring the packages yourself. PlanetCCRMA enables you to replicate the environment that computer music researchers have been using at Stanford, on your very own workstation!

PlanetCCRMA is relatively easy to install. It involves first using RPM to install their special pre-configured version of apt-get. Then all you do is issue a few apt-get commands that will upgrade your system and then download all the applications and drivers you need.

I will defer to CCRMA's web pages for more detailed install instructions, as these may vary per your specific version of Fedora Core. You can find the instructions at the PlanetCCRMA homepage.

I used the Linux Software RAID tools to create the RAID array. Once I had the device names of my two 200GB drives (/dev/hda and /dev/hdc) I just had to issue a few commands to get it working.

mdadm is a program to create and manage RAID arrays under Linux Software Raid. It should be included with Fedora. The following command created the array:

/sbin/mdadm   --create /dev/md0 --auto=yes  \
              --level=1 --raid-devices=2 /dev/hda /dev/hdc

The "level 1" is for mirroring. This means both drives will always hold the same data.

Next we must create a file system on the new device, md0. I chose the Silicon Graphics XFS file system due to its support for large files, crash recovery, and reportedly better data throughput.

The following command created the XFS file system:

/sbin/mkfs.xfs /dev/md0

Upon each bootup, we must "assemble" and mount the RAID array.

/sbin/mdadm -A /dev/md0 /dev/hda /dev/hdc
mount -t xfs /dev/md0 /md0

I don't like automatic updating of /etc/fstab. It can cause devices to be mounted at odd times, instead of when the user commands the machine to mount—which can cause latency problems. In Fedora Core 3, you can turn it off with these commands:

FSTAB_SYNC_SYM=/etc/hal/device.d/50-fstab-sync.hal
rm -f $FSTAB_SYNC_SYM
ln -s /bin/false $FSTAB_SYNC_SYM

(See the manual on fstab-sync for more information on disabling it for your system.)

I also decided I don't like DVD drives being under "/media". Instead I mount them at "/dvd1" and "/dvd2". These are easier to type than "/media/cdrecorder" and so on. The following commands accomplish this.

# make backup of fstab
cd /etc
cp fstab fstab.bak

# fix default mountpoints by filtering fstab
(cat /etc/fstab.bak | sed \
-e "s:/media/cdrom:/dvd1:g" \
-e "s:/media/cdrecorder:/dvd2:g" \
-e "s:,managed: :g") > fstab

For fast, efficient management of windows and desktops, may I humbly recommend the Lars Window Manager (also known as Larswm.) Larswm is known for its speed of operation and efficient resource usage. I've found it to be a great companion to my audio work.

Just one example: Larswm binds many actions to the status bar at the bottom of the screen. You don't have to actually find and hit a button to switch desktops—just sweep the mouse to anywhere at the bottom of the screen, and spin the mouse wheel to switch desktops quickly and silently (once again, important when recording in the same room.) The same goes for moving and resizing windows—you never have to hunt for the tiny corners or edges of a window again.

GNU Emacs is a great text editor, but did you also know it's an online chat program, project management system, and enhanced system administration tool?

Emacs is also quite resource-efficient, when you consider how many things it can do. This is important on an audio machine that doubles as my personal PC. Emacs' variety of available tools makes it a viable alternative to resource-hungry environments like GNOME.

I'll mention one other Emacs-related tool, called EevMode. It's a sort of front end to the shell that helps in automating common tasks. I use it to launch other applications from within Emacs, and to script common tasks like CD/DVD burning.

To learn more about eev-mode, visit the eev home page.

Miller Puckette's Pure Data is installed as part of PlanetCCRMA's collection of audio applications. It's a low-latency audio processing and synthesis environment designed around a graphical dataflow language. While the learning curve is a bit steep at first, I've found that Pure Data is a great environment for many types of audio work—effects processing, routing, and especially in building software synthesizers to control via MIDI. In fact, I specifically chose the M-Audio Keystation 88 Pro because I knew it'd have plenty of assignable knobs to control Pure Data.

You can find out more about Pure Data at Miller Puckette's pd page.

Ardour, the indispensable multitrack hard-disk recording software for Linux, is also installed as part of PlanetCCRMA. This is the bread and butter of recording an album with Linux.

You can find out more about Ardour at Ardour.org.