UDF = Universal Disk Format A file format standard originally proposed by the Optical Storage Technology Association as a universal standard for future variants of CD technology but later taken up by ECMA and ISO and is now suitable for use on just about any type of disk media. Needed since the original Compact Disc specification did not include a file system (there is raw data on the disk in streams) and this lead to lots of incompatible propriety file-system implementations. Most notably used in the DVD standard.
Uncle Technology A derogatory term taken from the computer industry, either technical advice with not even a tenacious link to reality or a hardware/software modification by someone that has no idea what he is doing. This sort of technical expertise is usually dispersed by your 13 year old nephew, some unidentified uncle (hence term), or this website.
Unipivot = Universal Pivot Also known by the alternative name unipoise = universal balance, an unipivot is a type of a bearing that allows the contact surface to move in any direction unlike a ball bearing that will only allow movement in one direction. Used in turntable arms and it is usually a steel pin with either a needle or cone point, this sort of design needs to be damped otherwise it has a tendency to jump and in cheap arms damped with rubber or other cheap materials and in hi-fi tonearms with oil or silicone baths. Some unipivot arms are actually hybrids, having both a pivot needle and balls revolving around it like in a ball bearing.
Unit Audio Archaic English term for hi-fi separates occasionally used in the UK, note that the term meaning has changed a bit over the years, in the 50's and up to the late 70's any audio equipment that had the speakers separate from the rest of the system could be considered unit audio, traditional consoles having the speaker or speakers built into the base unit. In fact to qualify as unit audio, a console by definition only had to have one speaker adjunct from the base, this usage of the term stopped when consoles were replaced in the marketplace by Music Systems and if you see it used today it is as a to denote separates sold as a unit or a system.
Upsampling Usually when a DAC has a higher bitrate and/or sampling frequency than the material it's converting what you gain is basically improved headroom since the data that the converter is getting is still confined to the lower bitrate (i.e. the same granularity of a signal), upsampling is a technique whereby the original digital information is first converted into the maximum bitrate and frequency that the converter is capable of prior to converting the information into an analogue signal, this means a although the amount of original information is the same the converter is getting more detailed information and thus puts out a more granular signal. The net result of this is highly dependent on the design of both the upsampling software and the DAC but can be quite an improvement. Despite claims by certain UK based manufacturers of an upsampling capable CD players, a 16bit signal converted into 24bit/192KHz (or whatever) will never be as good as material originally recorded in that resolution.
USB = Universal Serial Bus A high speed digital serial bus standard for computers and consumer electronics, developed by Intel in the early 1990's with the intention of getting rid of legacy I/O devices from the PC standard (i.e. Keyboard, mouse, parallel interface Printer and RS232 serial connectors which take 3 to 5 interrupts while each USB interface takes only one and can handle multiple devices while the legacy interfaces only handled one each). Intel had problems getting manufacturers to use the standard even though it was included on every motherboard chipset shipped by the company and it was ironically enough popularised by Apple Computer Corp. when they introduced the original iMac with the PC world following suit soon thereafter. Please note : It is often stated in technical publications that USB v.2 has a better transfer rate than the competing 1394 (i.e. that it is faster), this is a common misunderstanding based on the better theoretical burst rate of the USB v2 specification, the throughput of the current 1394 versions both in theory and even more so in practice is considerably better than of USB.
VAT = Value Added Tax A replacement for sales tax used primarily in Europe. Sales tax is a flat tax rate paid by consumers but collected by companies that sell the product to the consumer at the end of the manufacturing & sales chain, VAT is similarly a flat rate ultimately paid by consumers but unlike sales tax the VAT is levied at every stage of the manufacturing and sales chain, but companies can deduct VAT they have paid on their outgoings from their collection of VAT and can claim back from the tax authorities VAT when they export products.
Var A department on the Mediterranean coast of France that is the source of more than half of the world’s quality cane used in the making of reeds and double reeds, the local cane variety simply called “Var Cane” is ideal for musical instrument applications and is has meant that not only do they export cut and uncut cane in massive volumes but there have grown up a number of companies making reeds both under their own names and as OEM's. Most of them are based in the town of Grimaud or nearby villages such as Cogolin but local makers include ETS Rigotti.
VCA = Voltage Controlled Amplifier Just that, usually a small signal amplifier that can be controlled by a voltage for automation or remote control purposes, this is useful in compressors, noise reduction units and mixers of any kind (but not in volume controls Nb.). A difficult device to manufacture, the quality of the VCA is often the deciding factor in the sound quality or accuracy of the unit that's built around it.
Vicalloy = Vanadium, Iron and Cobalt Alloy An alloy used for magnetic recording, primarily in data recorders and loggers but also to a limited degree in audio recording. Usually not used in wire recording but pressed into flat strips and wound onto a reel and used like a recording tape, the recording head was also more like that of a tape recorder than a wire recorder. Primarily used by the USA Army from the early 50's and into the 70's as it was believed that it was more durable than tape based products. Vicalloy however is expensive and only a small handful of (mostly European) companies really made the metal in the qualities that where needed, to get around US laws that required that any material could only be supplied by USA based companies the alloy was usually imported in quantity and then wound onto reels, cut or otherwise processed, just enough to add enough value to be able to sell them as "made in the USA".