The Newbie's Guide to DIY Jargon September 25, 2010 12:31 1 Comment

One of the defining traits of any group of hobbyists is a penchant for jargon: long words get truncated after the first syllable, phrases get compressed into acronyms and initialisms, and some special items even get affectionate nicknames.  This is all well and good for the initiated, but it can be confusing for the fledging enthusiast who has just started poking around on DIY message boards.  So, for the latter group, I have compiled a list of all of the abbreviations, acronyms, and pseudonyms that I remember scratching my head over.

AD/DA: Analog-to-Digital or Digital-to-Analog converter

Converts an analog signal into 1s and 0s for digital processing, and the other way around.  "One way" converters are referred to as ADCs (Analog-to-Digital converter) or DACs (Digital-to-Analog Converter).

BOM: Bill Of Materials

A list of all of the components needed for a particular project, often distributed in Microsoft Excel format.  A savvy builder can easily suss one out from a schematic, but having a pre-made BOM can make life a lot easier for the beginner.

Cap: Capacitor

DOA/opamp: Discrete Operational Amplifier

An operational amp built from discreet components (transistors, resistors, etc.).  DOA's are at the heart of many popular projects, including API and Twin Servopreamps.

DI: Direct Input or Injection or Interface

Converts an instrument input into a microphone-level signal.  Usually found as either a built-in option on a preamp, or as a small, stand-alone box.

DIY: DIYourself

EQ: Equalizer

FET: Field Effect Transistor

A type of transistor often encountered in audio circuits and the basis for a unique class of compressors.

IC: Integrated Circuit

An electronic circuit shrunk into a tiny piece of semiconductor material.  Used in modern audio equipment for opamps, VCAs, etc.

HPF/LPF: High Pass Filter / Low Pass Filter LDC: Large Diaphragm Condenser microphone LED: Light Emitting Diode Omni: Omni-directional microphone

Opto: Optical compressor

A type of compressor that uses a light source and a photo-conductive cell to determine gain reduction.  Opto compressors are often chosen for their "musical" non-linearities.  The most famous optical compressor is the Urei/Universal Audio LA-2A.

PCB: Printed Circuit Board

Pot: Potentiometer

A variable resistor with a sliding contact used to control such diverse variables as gain, attenuation, panning, balance, compression ratio, impedance, attack time, etc... Also colloquially known as a "knob."

Pre/Mic pre: Microphone preamplifier

Takes signal from a microphone and amplifies it--sometimes known to do cool, non-linear things (distortion, compression) to the signal in the process.

PSU: Power Supply Unit

RU: Rack Unit

Standardized unit for measuring the height of 19" rack mount cases.  1RU=1.75" or 44.45mm.

SDC: Small Diaphragm Condenser microphone

Schemo: Schematic

A circuit diagram using lines and symbols to represent connections and components.  Reading a schematic is a valuable skill, but not essential for getting started in DIY.

SMD Surface Mount Device

A component that mounts directly to the surface of a circuit board.  Although SMDs are now predominant in consumer electronics, most DIY projects employ the older "thru-hole" mounting technology in which component leads are inserted into holes and soldered to pads on the PCB.

Trafo/Tranny/Iron: Transformer

TRS: Tip/Ring/Sleeve connectors

Also known as: phone, audio, 1/4" connectors.

Vari-µ: Variable-gain (µ) compressor. Pronounced "vari-mu."

A type of compressor than sets gain reduction according to changes in a tube's bias.  The Fairchild 660 is an especially famous variable-gain compressor.

VCA: Voltage Controlled Amplifier

An amplifier than varies it's gain according to a control voltage.  We often hear about VCAs in reference to VCA compressors, the most common and versatile type of hardware comp.

XLR: Cannon X Latch Rubber connector