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Magnetophon K1
Magnetophon was the brand or model name of the pioneering reel-to-reel tape recorder developed by engineers of the German electronics company AEG in the 1930s, based on the magnetic tape invention by Fritz Pfleumer. AEG created the world's first practical tape recorder, the K1, first demonstrated in Germany in 1935 at the Berlin Radio Show. A brief history of magnetic tape from the BASF Historian and the founding curator of the Ampex museum. Later models introduced the concept of AC tape bias, which improved the sound quality by largely eliminating background hiss. The resulting reproduction was so great an advance on any existing recording method that even those well acquainted with the industry could not tell the recordings from live play. Adolf Hitler used these machines to perform what appeared to be live broadcasts from one city while he was in another. A cache of 350 of these tapes was released years later when they were found in Koblenz. Two later model Magnetophons were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ton S
Ton is any of several units of measure of mass, volume or force. It has a long history and has acquired several meanings and uses. As a unit of mass, ''ton'' can mean: * the ''long ton'', which is * the ''tonne'', also called the ''metric ton'', which is ) or 1 megagram. * the ''short ton'', which is Its original use as a unit of volume has continued in the capacity of cargo ships and in units such as the '' freight ton'' and a number of other units, ranging from in size. Because the ton (of any system of measuring weight) is usually the heaviest unit named in colloquial speech, its name also has figurative uses, singular and plural, informally meaning a large amount or quantity, or to a great degree, as in "There's a ton of bees in this hive," "We have tons of homework," and "I love you a ton." History The ton is derived from the '' tun'', the term applied to a cask of the largest capacity. This could contain a volume between , which could weigh around , and occupy som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron(II,III) Oxide
Iron(II,III) oxide, or black iron oxide, is the chemical compound with formula Fe3O4. It occurs in nature as the mineral magnetite. It is one of a number of iron oxides, the others being iron(II) oxide (FeO), which is rare, and iron(III) oxide (Fe2O3) which also occurs naturally as the mineral hematite. It contains both Fe2+ and Fe3+ ions and is sometimes formulated as FeO ∙ Fe2O3. This iron oxide is encountered in the laboratory as a black powder. It exhibits permanent magnetism and is Ferrimagnetism, ferrimagnetic, but is sometimes incorrectly described as Ferromagnetism, ferromagnetic. Its most extensive use is as a black pigment (see: Mars Black (pigment), Mars Black). For this purpose, it is synthesized rather than being extracted from the naturally occurring mineral as the particle size and shape can be varied by the method of production. Preparation Heated iron metal interacts with steam to form iron oxide and hydrogen gas. :3Fe + 4H2O->Fe3O4 + 4H2 Under Hypox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vienna Philharmonic Orchestra
Vienna Philharmonic (VPO; ) is an orchestra that was founded in 1842 and is considered to be one of the finest in the world. The Vienna Philharmonic is based at the Musikverein in Vienna, Austria. Its members are selected from the orchestra of the Vienna State Opera. Selection involves a lengthy process, with each musician demonstrating their capability for a minimum of three years' performance for the opera and ballet. After this probationary period, the musician may request an application for a position in the orchestra from the Vienna Philharmonic's board. The Vienna Philharmonic hires no musician over 35 years of age, and has a mandatory retirement age of 65; 30 years of service are required for full pension. History Precursors and formation Until the 1830s, orchestral performance in Vienna was done by ''ad hoc'' orchestras, consisting of professional and (often) amateur musicians brought together for specific performances. In 1833, Franz Lachner formed the forerunner of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Strauss
Richard Georg Strauss (; ; 11 June 1864 – 8 September 1949) was a German composer and conductor best known for his Tone poems (Strauss), tone poems and List of operas by Richard Strauss, operas. Considered a leading composer of the late Romantic and early Modernism (music), modern eras, he has been described as a successor of Richard Wagner and Franz Liszt. Along with Gustav Mahler, he represents the late flowering of German Romanticism, in which pioneering subtleties of orchestration are combined with an advanced harmony, harmonic style. Strauss's compositional output began in 1870 when he was just six years old and lasted until his death nearly eighty years later. His first tone poem to achieve wide acclaim was ''Don Juan (Strauss), Don Juan'', and this was followed by other lauded works of this kind, including ''Death and Transfiguration'', ''Till Eulenspiegel's Merry Pranks'', ''Also sprach Zarathustra'', ''Don Quixote (Strauss), Don Quixote'', ''Ein Heldenleben'', ''Symph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wiener Staatsoper
The Vienna State Opera (, ) is a historic opera house and opera company based in Vienna, Austria. The 1,709-seat Renaissance Revival venue was the first major building on the Vienna Ring Road. It was built from 1861 to 1869 following plans by August Sicard von Sicardsburg and Eduard van der Nüll, and designs by Josef Hlávka. The opera house was inaugurated as the "Vienna Court Opera" (''Wiener Hofoper'') in the presence of Emperor Franz Joseph I and Empress Elisabeth of Austria. It became known by its current name after the establishment of the First Austrian Republic in 1921. The Vienna State Opera is the successor of the old Vienna Court Opera (built in 1636 inside the Hofburg). The new site was chosen and the construction paid by Emperor Franz Joseph in 1861. The members of the Vienna Philharmonic are recruited from the Vienna State Opera's orchestra. The building is also the home of the Vienna State Ballet, and it hosts the annual Vienna Opera Ball during the ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
78 Rpm
A phonograph record (also known as a gramophone record, especially in British English) or a vinyl record (for later varieties only) is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts near the outside edge and ends near the center of the disc. The stored sound information is made audible by playing the record on a phonograph (or "gramophone", "turntable", or "record player"). Records have been produced in different formats with playing times ranging from a few minutes to around 30 minutes per side. For about half a century, the discs were commonly made from shellac and these records typically ran at a rotational speed of 78 rpm, giving it the nickname "78s" ("seventy-eights"). After the 1940s, "vinyl" records made from polyvinyl chloride (PVC) became standard replacing the old 78s and remain so to this day; they have since been produced in various sizes and speeds, most commonly 7-inch discs pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude (magnitude of the voltage or current) of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is defined as a circuit that has a power gain greater than one. An amplifier can be either a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be categorized in different ways. One is by the frequency of the electronic signal being amplified. For ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AC Bias
Tape bias is the term for two techniques, AC bias and DC bias, that improve the fidelity of analogue tape recorders. DC bias is the addition of direct current to the audio signal that is being recorded. AC bias is the addition of an Ultrasound, inaudible high-frequency signal (generally from 40 to 150 kHz) to the audio signal. Most contemporary tape recorders use AC bias. When recording, magnetic tape has a Nonlinearity, nonlinear response as determined by its coercivity. Without bias, this response results in poor performance, especially at low signal levels. A recording signal that generates a magnetic field strength less than the tape's coercivity cannot magnetise the tape and produces little playback signal. Bias increases the signal quality of most audio recordings significantly by pushing the signal into more Linearity, linear zones of the tape's magnetic transfer function. History Magnetic recording was proposed as early as 1878 by Oberlin Smith, who on 4 Oct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reichs-Rundfunk-Gesellschaft
The Reichs-Rundfunk-Gesellschaft (RRG; ''Reich Broadcasting Corporation'') was a national network of German regional public radio and television broadcasting companies active from 1925 until 1945. RRG's broadcasts were receivable in all parts of Germany and were used extensively for Nazi propaganda after 1933. Historical recordings of RRG broadcasts are today held by the German Broadcasting Archive. History The company was established in Berlin on 15 May 1925 with a start capital of 100,000 Reichsmark as an umbrella organisation by nine regional broadcasters – that is to say, all of the German radio stations other than the Deutsche Stunde in Bayern – serving the various states of the Weimar Republic. From 1926, a majority share was held by the state-owned Deutsche Reichspost authority, represented by RF engineer and Reichspostministerium official Hans Bredow as chairman in the rank of a ''Reichs-Rundfunk-Kommissar''. The logo of the RRG was designed by German graph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Weber (engineer)
Walter Weber (26 March 1907 in Gelsenkirchen – 18 July 1944 in German-occupied Kościan) was a German pioneer of electromagnetic sound recording. From 1925 to 1927 he studied at the Oldenburg Academy of Engineering. From 1 May 1928 to 31 December 1930 he was an engineer at the central laboratory of Siemens & Halske AG in Berlin. There he met Hans-Joachim von Braunmühl. When he moved to the laboratory of the Reichs-Rundfunk-Gesellschaft The Reichs-Rundfunk-Gesellschaft (RRG; ''Reich Broadcasting Corporation'') was a national network of German regional public radio and television broadcasting companies active from 1925 until 1945. RRG's broadcasts were receivable in all parts o ..., he followed him there in 1931. On 2 November 1938, he defended his thesis ''Das Schallspektrum von Knallfunken und Knallpistolen mit einem Beitrag über Anwendungsmöglichkeiten in der elektroakustischen Meßtechnik''. (''The sound spectrum of spark transmitters and oscillators with a contribution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DC Bias
In signal processing, when describing a periodic function in the time domain, the DC bias, DC component, DC offset, or DC coefficient is the mean value of the waveform. A waveform with zero mean or no DC bias is known as a ''DC balanced'' or ''DC free'' waveform. Origin The term originates in electronics, where ''DC'' refers to a direct current voltage. In contrast, various other non-DC frequencies are analogous to superimposed alternating current (AC) voltages or currents, hence called AC component or AC coefficients. Applications In the design of electronic amplifier circuits, every active device has biasing to set its ''operating point'', the steady state current and voltage on the device when no signal is applied. In bipolar transistor biasing, for example, a network of resistors is used to apply a small amount of DC to the base terminal of the transistor. The AC signal is applied at the same terminal and is amplified. The bias network is designed to preserve the applied AC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
