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  1. Measurement and Perception of Regular Loudspeaker Distortion June 03, 2015 By Wolfgang Klippel and Robert Werner - Klippel GmbH, Dresden, Germany Article originally published in Voice Coil, May 2011 A major part of the signal distortion generated by loudspeaker systems is directly related to the geometry and properties of the material used in loudspeaker design and found in all good units passing the assembly line. Those regular distortions are the result of an optimization process giving the best compromise between perceived sound quality, maximal output, cost, weight, and size. This article discusses the physical causes of the regular distortions, their modeling by using lumped and distributed parameters, the objective assessment using modern measurement techniques, and the perception by the human ear. The target of an audio reproduction system is to generate at the listening position an output signal pout(t), which is similar to the input signal pin(t) at the source point. The difference between the two time signals may be considered as a distortion signal pdist(t)=pout(t) - pin(t) generated somewhere in the audio chain. After introducing digital signal processing, transmission, and data storage, the weakest part is the electroacoustical conversion (loudspeaker) and in the interaction with an acoustical environment (room). Figure 1: Signal flow diagram showing the generation of signal distortion in a loudspeaker system. The generation of signal distortion can be modeled by a flowchart as shown in Fig. 1. It comprises a linear and a nonlinear model, a black box system describing further defects and faults in the system and an independent noise source. The linear and the nonlinear models describe the target performance of the loudspeaker, which should be materialized in the golden reference units at the end of loudspeaker development. The outputs of the linear and nonlinear models are regarded as regular distortions because they are accepted within the design process and are the result of an optimization process giving the best compromise with other constraints (weight, size, cost, and so on). Irregular distortions are generated by defects caused by the manufacturing process, aging, and other external impacts (overload, climate) during the later life cycle of the product. A rubbing voice coil, buzzing parts, loose particles, and air leaks are typical loudspeaker defects which produce irregular distortions which are quite audible and not acceptable. A related paper discusses the physical causes and measurement techniques in greater detail. This article focuses on the regular distortions generated by the linear and nonlinear models which are the theoretical basis of the loudspeaker design process. Linear modeling based on lumped parameter modeling (Thiele/ Small parameters) has a long history in loudspeaker design. More complex models using distributed parameters have been introduced to explain the cone vibration and sound radiation at higher frequencies. The linear modeling fails in describing the large signal performance of the loudspeaker which is directly related to maximal output and cost, size, and weight of the loudspeaker. Therefore, modeling and direct measurement of loudspeaker nonlinearities is an important part of modern loudspeaker design. Table 1- Overview on meaningful measurements for assessing the linear signal distortion generated in loudspeaker systems and identifying the physical causes. Linear Distortion Table 1 gives an overview of dominant causes of linear distortion caused by transducer and system design and by the acoustical environment in the final application. The first causes are in the one-dimensional signal path close to the input of the transducer which can be modeled by a network comprising lumped elements. Electrical measurements of voltage and current at the terminals gives the electrical impedance which is the basis for identifying basic lumped parameters and other derived Thiele/Small parameters which describe the properties of electrodynamic transducer, mechanical resonator, and acoustical load. At higher frequencies the radiator (cone or diaphragm) does not vibrate as a rigid body anymore but breaks up into higher-order modes. Here, a more complex model using distributed parameters and multiple state variables such as the displacement X® on sufficient points r on the radiator’s surface is required. New mechanical measurements using laser scanning techniques provide the displacement and the geometry of the vibrating surface. The generated sound pressure in the near field or in the far field at the listening position depends not only on the sound radiation but also on the diffraction at the edges of the enclosure, early reflections on room boundaries, and room modes. In micro-speakers, headphones, and horn compression drivers, the acoustical sound field may generate a force F® at any point of the vibrating surface which is not negligible and may be also detected in the electrical signals at the terminals. Figure 2: Prediction of the regular transfer characteristics of loudspeakers by using a linear and nonlinear model. Figure 3: Modeling the small signal performance of loudspeaker systems by using lumped and distributed parameters. Traditional loudspeaker design and evaluation of transfer behavior was restricted to electrical and acoustical measurements as shown in Fig. 3. New cost-effective laser sensors based on the triangulation principle(1) provide the geometry of the radiating surface at high accuracy and the linear transfer functions between terminal voltage and displacement X® at sufficient points r on the surface. Figure 4 shows, for example, the result of such a scanning process collecting mechanical information at about 1000 measurement points. The mechanical scanning process requires no anechoic room and may be applied to the drive unit operated in a vacuum. Numerical calculation based on the scanned data provides the sound pressure on-axis or at any point in the far field giving the polar pattern of the loudspeaker as illustrated in Fig. 5. A new Sound Pressure Related Decomposition Method(2) shows how each part of the cone contributes to the sound pressure output in a constructive or destructive way. This reveals acoustical cancellation effects, critical rocking modes, and undesired circumferential modes. A Modal Analysis applied to the mechanical data simplifies the mechanical analysis and provides the modal loss factor η and other material parameters which are important input parameters for a Finite Element Analysis to investigate the design choices in greater detail. A Boundary Element Analysis may also consider the particular shape of the enclosure, horn, or room boundaries to predict the sound field at high accuracy. Figure 4: A critical vibration pattern depicted as a sectional view (left down) and as 3D animation (right) of a soft dome tweeter at 15kHz causing a peak in the sound pressure on-axis response (upper left). Three curves calculated from the mechanical scanning data give the most condensed but almost comprehensive description of a loudspeaker’s small signal performance: The on-axis sound pressure response predicted in 1m distance in the far field is depicted as a dotted line in Fig. 6. The thick line represents the sound power response of the loudspeaker, and the thin line on the top shows the accumulated acceleration level (AAL). The AAL corresponds to the total mechanical energy neglecting the phase information but normalized in such a way as to be comparable with the acoustical output. It may be interpreted as the maximal acoustical sound pressure level while neglecting any acoustical cancellation. Therefore, the AAL and SPL curves are identical at low frequencies (in Fig. 6 up to 800Hz), where the loudspeaker cone vibrates in the rigid body mode and all points on the cone contribute to the sound pressure output constructively. However, at distinct frequencies such as 1.1, 4.4, and 7kHz, there are significant dips in the SPL output which are not found in the AAL. The difference between AAL and SPL curves describes the acoustical cancellation effect quantitatively. The AAL response comprises characteristic peaks which occur at the natural frequencies of the higher-order modes. The 3dB bandwidth of each “resonance peak” corresponds with the modal loss factor of the material used. At low frequencies the sound power response is most identical with both AAL and SPL responses because the loudspeaker dimensions are small compared to the wavelength and the radiator behaves as an omnidirectional source. Figure 5: Vibration and radiation analysis using distributed loudspeaker parameters (geometry and vibration of the radiator’s surface) measured by laser scanning techniques. Figure 6: The most important loudspeaker characteristics in the small signal domain: Accumulated acceleration level (AAL) as thin line describes the mechanical vibration of the radiator’s surface and is directly comparable with the on-axis sound pressure level (SPL) as dotted line and the total acoustical sound power response depicted as thick line. Regular Nonlinear Distortion Table 2 gives an overview on the physical causes of regular nonlinear distortion affecting the loudspeaker’s large signal performance(3). The dominant nonlinearities are in the motor and suspension part of the electrodynamical transducer because the voice coil displacement is relatively large compared to the dimensions of the coil-gap configuration and size of the corrugation rolls in the suspension (spider, surround). In micro-speakers, headphones, and compression drivers, the air flow in the gap may generate a nonlinear dependency of the mechanical resistance Rms(v) on velocity v. In vented-box loudspeaker systems there is a similar mechanism causing a nonlinear flow resistance Rap(vp). High local displacement at the surround and particular regions on the cone activate nonlinearities in the modal vibration. A typical nonlinearity related to the sound radiation is the Doppler Effect where the high excursion of the bass signal changes the position of the cone causing variation in the propagation time affecting high frequency components radiated from the radiator at the same time. In horn compression drivers the high sound pressure causes a gradual steeping of the waveform while the sound wave is traveling from the throat to the mouth of the horn. The effect of the dominant nonlinearities can be investigated by the lumped parameter model shown in Fig. 7. Contrary to a linear model some elements have not a constant parameter but depend via a nonlinear function on voice coil displacement x, velocity v, current i, sound pressure in box enclosure pbox, or other state variables. Table 2- Overview on meaningful measurements for assessing the regular nonlinear signal distortions generated in loudspeaker systems and identifying their physical causes. Figure 7: Lumped parameter model of a vented-box loudspeaker system considering the dominant nonlinearities in the electrical, mechanical, and acoustical domain. The shape of the nonlinear parameter characteristics is directly related to the geometry and properties of the material. Figure 8 shows the nonlinear stiffness Kms(x) of the total suspension as the solid thick curve in the right diagram increasing at positive and negative displacements. This is very typical for any spider and surround when the shape of the corrugation rolls is deformed at high excursions. The solid curve in Fig. 8 also reveals an asymmetry in the stiffness characteristic which is caused by the asymmetrical shape of the surround which is more stiff and less compliant for positive than negative excursion. This asymmetry is an undesired property which causes not only 2nd- and higher-order distortion but also generates a DC displacement moving the coil to the softer side of the suspension. Nonlinearities may also cause an instability of the motor at frequencies above resonance. The large signal performance is predictable and there is close relationship via the nonlinear parameters to the design. The generation of nonlinear distortion and other symptoms depends on the properties of the stimulus. A single tone generates new spectral components at multiples of the fundamental frequency which can easily be measured by conventional harmonic distortion measurements. Figure 9 shows the response of the total harmonic distortion (THD) and relationship to the physical causes. The high level of the harmonic distortion below 150Hz is caused by voice coil displacement x activating the stiffness Kms(x) or force factor nonlinearity Bl(x). The displacement varying inductance L(x) can only generate low values of THD in a narrow frequency range just above resonance (150-200Hz). Figure 8: Nonlinear stiffness characteristic K(x) versus displacement x of the mechanical suspension (surround and spider) dynamically measured by modern system identification using the electrical signals at loudspeaker terminals. The inductance nonlinearity L(i) varying with current i may contribute to the THD at higher frequencies. The distinct peak in THD at 2kHz is caused by a nonlinear vibration of the cone and surround after break-up. Unfortunately, harmonic distortion measurement does not give a comprehensive picture of the large signal performance of loudspeaker systems. At least a second tone is required to generate intermodulation products which occur at difference and sum frequencies in all possible combinations of the excitation frequencies. Increasing the number of fundamental components in multi-tone stimulus will generate more and more intermodulation components spreading over the complete audio band. Contrary to the THD response in Fig. 9, the nonlinear force factor Bl(x) and the inductance L(x) THD generate significant intermodulation distortion at higher frequencies as illustrated in Fig. 10. Thus, harmonic distortion measurements using a single test tone are not sufficient for assessing loudspeakers comprehensively and predicting the large signal performance for complex stimuli like music. Figure 9: Relationship between the dominant loudspeaker nonlinearities (causes) and the total harmonic distortion (nonlinear symptom) generated by a single-tone swept continuously versus frequency. Impact on Perceived Sound Quality The reproduced sound quality as perceived by a listener is one of the most important criteria for the preference of an audio product. Systematic subjective evaluation requires a double-blind test strategy and psychometrical tools for assessing the sensations reliably and quantitatively. Such tests are time-consuming and expensive and the results depend on the particular listening condition (room, program material) and the training of the listeners. Thus it is desirable to predict those subjective sensations based on objective measurements and perceptive modeling considering the interactions between stimulus, loudspeaker, room, ear, and the listener’s training and expectations. Figure 10: Relationship between the dominant loudspeaker nonlinearities (causes) and the nonlinear distortion generated by a sparse multi-tone stimulus. There are two alternative approaches using different sources One is based on personal listening experience, vague speculations, or even myths. This reflects the heritage of accumulated knowledge, which is difficult or impossible to verify by science. Exploiting this expertise is beneficial as long as it is combined with a critical attitude and some common sense. Wrong conceptions will die eventually and the falsification of those ideas are interesting research topics which accelerate this clarification. The other approach is based on facts accumulated by psychoacoustical research modeling the basic processing in the ear. Unfortunately, there are still many open questions how to apply the results of those fundamental experiments to sound reproduction of natural audio signals. Figure 11 gives an overview of the current objective methods on assessing the sound quality of loudspeaker systems. The parameter-based method relies on loudspeaker characteristics such as lumped and distributed parameters which are independent of the stimulus. The interpretation of harmonic distortion and other nonlinear distortion belongs to the stimulus-based method which considers the properties of a particular stimulus, position of the listening position, and the influence of the acoustical environment. The linear and nonlinear distortions separated from undistorted stimulus are the input of the following psychoacoustical model considering generating basic perceptual attributes (loudness, sharpness, roughness) and overall judgments describing the pleasantness of the sound and preference considering the ideal conceptions of the listener(10). Figure 11: Objective methods for assessing the sound quality of loudspeaker systems. The psychoacoustical model performs a binaural nonlinear processing in which a significant part of the distortion component is masked by other signal components. The following main mechanisms are summarized and consequences for interpreting objective measurements are discussed: • Spectral components within third-octave bandwidth contribute to the same excitation level above 400Hz. Smoothed amplitude response describes the perception of stimuli having a dense spectrum (e.g., pink noise). The shape of a resonance (gain, Q factor) has a minor influence on audibility as long as the excitation within the critical band is constant6. • Spectral components below 100Hz contribute to the excitation level of one critical band. Sufficient bass sensation can be generated by higher frequencies (60…100Hz) when the very low frequency components (20…40Hz) are attenuated by the cutoff frequency of the loudspeaker. • A variation larger than 1dB in the excitation level within a critical band becomes audible. • Spectral masking excites adjacent bands. Dips in the frequency response are less audible than peaks. Nonlinear distortion components are masked by fundamental components(7). • Temporal masking. The RMS value (rather than the peak value) determines the audibility of the regular nonlinear distortion. • Hearing threshold. Bass components are not audible if the listening level is too low. A small level difference of components close to the hearing threshold may cause a significant difference in perceived bass sensation and in the detection of nonlinear distortion. • Monaural processing is not very sensitive for phase shift of signal components processed in separate critical bands. Phase distortion corresponding with a group delay variation of 0.4…2ms within a critical band changes the timbre and roughness of the sound. • Binaural processing(5) is sensitive for interaural level differences (1…2dB) and time delay (50μs). Latency and group delay response should be identical in the symmetrical channels of a multi-way system to avoid lateralization of the perceived sound image. • Precedence effect(4) maintains the primary image as long as the lateral reflections are sufficiently low or the time delay is small. Strong reflections after 80ms are unpleasant and are perceived as echo. • Audible lateral reflections may generate a preferred sensation of spaciousness and a broadening of the primary image(12); the optimal delay and level depend on the property’s audio signal (20ms delay for speech or 40ms for music and reflections having the same level as the direct sound). Early reflections as found in relatively small rooms improve sound quality; artificial generation of lateral reflections may be desired in an anechoic environment or small rooms (cars). • Adaptation(6) to the acoustical environment causes a variation of the ideal conceptions versus time. The listener becomes less sensitive to linear distortion caused by room and loudspeaker after some time. • Intermodulation distortion is detected by the ear not only by exploiting spectral but also temporal clues. Amplitude modulation is much more audible than frequency modulation and is perceived as fluctuation (modulating bass tone f1 400Hz). Low amplitude intermodulation distortion at 1-3% caused by nonlinear force factor Bl(x) and inductance L(x) is detected as an unnatural roughness. Figure 12: Simulation and auralization of loudspeaker distortion in reproduced audio signal based on linear and nonlinear modeling and using natural audio signals (music, speech) or artificial test signals. Auralization Techniques Although the perceptive modeling gives valuable insight into fundamental psychoacoustical mechanisms and basic sound attributes, it is not very accurate in predicting the overall assessment of the perceived sound quality and in the preference of an audio product at the current state. The ideal conceptions of a listener highly depend on training, listening habits, fashion, cultural factors, and artistic properties of the program material. Some linear and nonlinear distortion is clearly audible but may be acceptable for a particular application and program material (popular music) or may even be perceived as an interesting effect (artificial bass enhancement). The reliable evaluation of those criteria requires systematic listening tests using modern auralization techniques(8), (9). Figure 12 shows a digital signal processing system based on loudspeaker modeling to generate a virtual audio system. This model has a sandwich structure in which a nonlinear system modeling the dominant nonlinearities in the electrodynamical transducer is embedded by linear systems. The first linear system corresponds with the electrical signal path from the source to the loudspeaker terminals, while the second linear system models the signal path in the mechanical and acoustical domain where the amplitude is relatively small and the sound propagation is sufficiently linear. This technique is a convenient tool for investigating design choices before a first prototype is made and combines subjective and objective evaluation. Conclusions Linear and nonlinear distortion is unavoidable in current electroacoustical transducers using a moving coil assembly driving diaphragms, cones, and other radiators. The regular distortion is deterministic and can be predicted by using linear and nonlinear models and identified loudspeaker parameters in an early design stage. Finding acceptable limits for those regular distortions is an important part in defining the target performance at the beginning of loudspeaker development. Subjective evaluation is required to assess the audibility and the impact on perceived sound quality. Some distortions which are audible might still be acceptable or even desirable in some applications. Systematic listening tests, nonlinear auralization, and objective assessment based on a perceptual model are useful tools to assess regular distortion. References 1. Klippel, W.; Schlechter, J.: “Distributed Mechanical Parameters of Loudspeakers Part 1: Measurement,” J. Audio Eng. Society 57, No. 9 pp. 696-708 (2009 Sept.). 2. Klippel, W.; Schlechter, J.: “Distributed Mechanical Parameters of Loudspeakers Part 2: Diagnostics,” J. Audio Eng. Society 57, No. 9 pp. 696-708 (2009 Sept.). 3. Klippel, W.: Tutorial: “Loudspeaker Nonlinearities - Causes, Parameters, Symptoms,” J. Audio Eng. Society 54, No. 10 pp. 907-939 (2006 Oct.). 4. Zwicker, E.; Fastl, H: Psychoacoustics – Facts and Models. Springer, Berlin, 1999, ISBN 3-540-65063-6. 5. 5. Blauert, J.: “Spatial Hearing,” Hirzel Verlag, MIT, 1997. 6. Toole, F. E.; Sound Reproduction, Focal Press, Amsterdam, 2008. 7. Gäßler, G; “Die Grenzen der Hörbarkeit nichtlinearer Verzerrungen bei der Übertragung von Instrumentenklängen,” Frequenz, Volume 9 (1955), Nr. 1, pages 15–25. 8. Klippel, W: “Speaker Auralization – Subjective Evaluation of Nonlinear Distortion,” presented at the 110th Convention of the Audio Eng. Soc., Amsterdam, May 12-15, 2001, preprint 5310, J. of Audio Eng. Soc., volume 49, No. 6, 2001 June, p. 526. (abstract). 9. Klippel, W.: “Auralization – Subjective Evaluation of Speaker Distortion,” Fortschritte der Akustik - Plenarvorträge und Fachvorträge der 27. Jahrestagung für Akustik DAGA 01, Hamburg, 2001. 10. Klippel, W: “Multidimensional Relationship between Subjective Listening Impression and Objective Loudspeaker Parameters,” Acustica 70, Heft 1, S. 45-54, 1990. 11. Klippel, W.: “Zusammenhang zwischen objektiven Lautsprecherparametern und subjektiver Qualitätsbeurteilung,” Beitrag in Angewandte Akustik 1, S. 46-101, Verlag Technik Berlin, 1987. 12. Ando, Y.: “Subjective Preference in Relation to Objective Parameters of Music Sound Fields with a Single Echo,” J. Acoust. Soc. Am. 62, pp. 1436.
  2. Intel and Micron Announce New Class of Memory 1,000 Times Faster than NAND July 29, 2015 by audioXpress Staff Intel and Micron announced a new class of non-volatile memory, creating the first new memory category in more than 25 years. The new 3D XPoint technology, now in production, brings non-volatile memory speeds up to 1,000 times faster than NAND, the most popular non-volatile memory in the marketplace today. The two companies invented unique material compounds and a cross point architecture for a memory technology that is 10 times denser than conventional memory. 3D XPoint technology makes new innovations possible in applications ranging from machine learning to real-time tracking of diseases and immersive 8K gaming and has the potential to revolutionize any device, application or service that benefits from fast access to large sets of data. This is also the first new memory category to reach the market since the introduction of NAND flash in 1989. 3D XPoint technology is up to 1000x faster than NAND and an individual die can store 128Gb of data (Photo: Business Wire) According to Intel and Micron, 3D XPoint technology combines the performance, density, power, non-volatility and cost advantages of all available memory technologies on the market today. The technology is up to 1,000 times faster and has up to 1,000 times greater endurance than NAND, and is 10 times denser than conventional memory. “For decades, the industry has searched for ways to reduce the lag time between the processor and data to allow much faster analysis,” said Rob Crooke, senior vice president and general manager of Intel’s Non-Volatile Memory Solutions Group. “This new class of non-volatile memory achieves this goal and brings game-changing performance to memory and storage solutions.” “One of the most significant hurdles in modern computing is the time it takes the processor to reach data on long-term storage,” said Mark Adams, president of Micron. “This new class of non-volatile memory is a revolutionary technology that allows for quick access to enormous data sets and enables entirely new applications.” 3D XPoint technology wafers are currently running in production lines at Intel Micron Flash Technologies fab (Photo: Business Wire) As the digital world quickly grows – from 4.4 zettabytes of digital data created in 2013 to an expected 44 zettabytes by 20204 – 3D XPoint technology can turn this immense amount of data into valuable information in nanoseconds. The non-volatile nature of the technology also makes it a great choice for a variety of low-latency storage applications since data is not erased when the device is powered off. Following more than a decade of research and development, 3D XPoint technology was built from the ground up to address the need for non-volatile, high-performance, high-endurance and high-capacity storage and memory at an affordable cost. It ushers in a new class of non-volatile memory that significantly reduces latencies, allowing much more data to be stored close to the processor and accessed at speeds previously impossible for non-volatile storage. The innovative, transistor-less cross point architecture creates a three-dimensional checkerboard where memory cells sit at the intersection of word lines and bit lines, allowing the cells to be addressed individually. As a result, data can be written and read in small sizes, leading to faster and more efficient read/write processes. Intel and Micron invented a unique cross point architecture for a memory technology that is 10 times denser. (Photo: Business Wire) Perpendicular conductors connect 128 billion densely packed memory cells. Each memory cell stores a single bit of data. This compact structure results in high performance and high-density bits. In addition to the tight cross point array structure, memory cells are stacked in multiple layers. The initial technology stores 128Gb per die across two memory layers. Future generations of this technology can increase the number of memory layers, in addition to traditional lithographic pitch scaling, further improving system capacities. The new memory technology also eliminates the need for transistors, increasing capacity while reducing cost. Memory cells are accessed and written or read by varying the amount of voltage sent to each selector. With a small cell size, fast switching selector, low-latency cross point array and fast write algorithm, the cell is able to switch states faster than any existing non-volatile memory technology today. 3D XPoint technology will sample later this year with select customers, and Intel and Micron are developing individual products based on the technology. www.intel.com | www.micron.com
  3. Нямах предвид synchu да се занимава. Надявах се да има някакъв интерес от страна на хилядите, посетили темата. Явно не оценявам реалното състояние на потенциала във форума. Някак все очаквам нещо различно от реалното, но това е моя грешка в оценяването. Ще се постарая в бъдеще да се съобразявам.
  4. 1000 musicians play Learn to Fly by Foo Fighters to ask Dave Grohl to come and play in Cesena, Italy Foo Fighters' Dave Grohl responds to the video of Rockin 1000 'Learn To Fly' https://youtu.be/txEUgZR-luU
  5. Отдавна се питвам да разнообразя темата, но ... Ето още един (може би последен) опит:
  6. Issuu Digital publication http://issuu.com/kimundo/docs/build_a_portable_synthesizer
  7. Best of Blues, from Mississipi to Chicago 00:00 - Howlin' Wolf - Smokestack Lightnin' 03:07 - John Lee Hooker - Boom Boom 05:35 - Muddy Waters - Rock Me 08:47 - Screamin' Jay Hawkins - I Put a Spell on You 11:12 - Big Mama Thornton - Hound Dog 14:02 - Aretha Franklin - Today I Sing the Blues 16:48 - Robert Johnson - Sweet Home Chicago 19:50 - Johnny Cash - I Walk the Line 22:34 - Fats Domino - Blueberry Hill 24:55 - Freddy King - I'm Tore Down 27:33 - Amos Milburn - One Scotch, One Bourbon, One Beer 30:47 - B.B. King - Sweet Little Angel 33:47 - Big Joe Turner - S. K. Blues, Pt. 1 36:48 - Sister Rosetta Tharpe- Crying in the Chapel (Ft. Kelly Owens Quartet) 39:16 - Albert King - Don't Throw Your Love on Me so Strong 42:13 - Howlin' Wolf - The Red Rooster 44:39 - Kokomo Arnold - Milk Cow Blues 47:46 - Jimmy Reed - Baby What You Want Me to Do 50:09 - The Coasters - Young Blood 52:30 - Sidney Bechet - Blues in Paris 55:50 - Leadbelly - Where Did You Sleep Last Night 58:52 - Chuck Berry - Driftin' Blues 01:01:13 - John Lee Hooker - Shake It Baby 01:05:18 - Skip James - Devil Got My Woman 01:08:17 - Johnny Cash - Folsom Prison Blues 01:11:03 - Memphis Slim - Nobody Loves Me 01:13:52 - Muddy Waters - Mannish Boy 01:16:48 - Howlin' Wolf - Spoonful 01:19:31 - Lightnin' Hopkins - Mojo Hand 01:22:31 - Jimmy Witherspoon- Ain't Nobody's Business (Ft. Jay McShann) 01:25:27 - Sidney Bechet - St. Louis Blues 01:29:40 - Jimmy Reed - Bright Lights, Big City 01:32:28 - Arthur 'Big Boy' Crudup - That's Allright 01:35:19 - Memphis Minnie - Me and My Chauffeur Blues 01:38:05 - J.B. Lenoir - Eisenhower Blues 01:40:58 - Chuck Berry - Worried Life Blues 01:43:08 - James Brown - Try Me 01:45:40 - Muddy Waters - Sugar Sweet 01:48:11 - Robert Johnson - Cross Road Blues 01:50:50 - Big Joe Williams - P-Vine Blues 01:54:01 - Howlin' Wolf - I've Got a Woman 01:56:55 - Sonny Boy Williamson - Stop Right Now 01:59:20 - T-Bone Walker - Call It Stormy Monday 02:02:21 - John Lee Hooker - Whiskey and Wimmen 02:05:18 - Jimmy Reed - Big Boss Man 02:08:07 - The Coasters - Down in Mexico 02:11:23 - Johnny Cash - Oh Lonesome Me 02:13:53 - Sidney Bechet - Blues My Naughty Sweetie Gives to Me 02:19:34 - Elmore James - Dust My Broom 02:22:19 - Bo Diddley - I'm a Man
  8. Ей, това вишистите сте опасна работа, бре! Човекът каза по-простичко да се обяснява, за да може да разбира, а вие - теория на музиката, калкулатори разни... Още малко спектрален анализатор и честотомер ще искате...
  9. От написаното до тук, явно компромисът ще е с качеството. И аз имам същия проблем. Всеки ден. Дори когато влизам в супермаркета за продоволствие.
  10. Buying a Tape Machine: An 11-Point Checklist — from “Midnight Bob” Shuster August 5th, 2013 by David Weiss Tape is still in high style in the audio world. Like a 1957 Corvette or a standup Pac Man machine, some technical pleasures never go out of fashion. “Midnight Bob” Shuster has been maintaining tape machines professionally since 1975. Although 99% of today’s audio facilities have a DAW as the center of operations, an element of analog tape processing remains a welcome element in a large number of studios. While many engineers are content to approximate the sound with the wide array of tape-emulating plugins currently available, there’s no shortage of recordists willing to go hard-core with an actual tape machine on hand. The problem for engineers, producers, studio owners, and archivists who have their heart set on obtaining a tape machine – whether it’s their first or is complementing one or more machines already in-house – is that there are virtually no new models on the market. Save for the Otari Mx5050 MKiii, which is still being made on a limited but costly basis, people who want/need tape will have to obtain a used machine. So how do you know if that shiny Studer A827 24-track 2” machine that you’ve just discovered for sale on Craig’s List is your dream machine, or a lemon? One man who can tell quickly is “Midnight Bob” Shuster of Long Island-based Shuster Sound, who stands among the country’s most experienced audio techs. A professional maintenance engineer since 1975, Shuster kept all the gear humming at top NYC facilities including the Power Station, Media Sound, Record Plant, Electric Lady, Sony Studios, Pomann Sound, Avatar, NBC, and many more. Today, Shuster’s clientele has grown to include an ever-expanding list of solo studio operators and engineers, as well as radio stations, who count on him to keep their analog gear running strong. Tape machine repair and maintenance can account for several of Shuster’s house calls each week, and while some of the newly-obtained Ampex, Otari, Studer, MCI and Scully machines he sees are running clean, others would be more useful as retro coffee tables. “NYC remains a hotbed of recording, and tape is enjoying a renaissance,” Shuster says. “I’m seeing that up-and-coming engineers, the old-timers, and everyone in between are discovering ways to combine the new and old. And people are saying, ‘I want an analog tape machine, because I know that it can make my record sound better.’” If you’re thinking of adding a vintage tape machine to your palette, then you need to know what potential pitfalls to watch out for while shopping. Useful maintenance tips are here as well, for those who take the plunge. Be sure to equip yourself with this essential checklist, as explained by Bob Shuster: It’s the Heads The tape heads of a Studer A820. (All photos by Bob Shuster – click photos to enlarge) A tape machine is only as good as the condition of its tape heads. Tape heads are the devices responsible for directly recording and playing back the magnetic pattern to or from the tape. Just like a phonograph stylus on a vinyl record (OK, I’m dating myself here), or a microphone, they are transducers. If a head is corroded, rusty or pitted, it will have an effect on the ability to accurately transfer the sound to a magnetic imprint on tape. Heads can either be relapped or replaced. Relapping is a process of returning the original contour to the face of the head. This is done through a highly refined process of compounding and polishing the head by a skilled specialist. Re-lapping is obviously the most economical choice, and most headstacks can be relapped between one and three times (depending on the amount of wear on the heads each time). A good test for a worn head is to take your fingernail and run it along the upper or bottom edge of the head — if you can feel a ridge or your nail catches on a ridge, it is a good idea to have it inspected for possible relapping. The exception to this would be an “undercut head” which actually has grooves cut just above the top and bottom of the head cores to help reduce edge wear and protect the tape. To those unfamiliar with headstacks, it is difficult to explain the differences between head wear and intentionally undercut heads, but it is most easily explained that the undercut head has wide machined grooves which is easy to see. If the head is not undercut, it should have a completely smooth surface and your nail should not catch on ridges. You may also see uneven patterns across the face of the head. Badly worn heads will have grooves at the top and bottom where the tape has travelled and causes level inconsistencies and can even damage the tape. Another indication of bad heads is that they may not play or record at all and they may be worn beyond what relapping can repair. If you’re not sure about you’re seeing, call somebody in to do an evaluation. If you’ve purchased the deck already, have the heads taken off the machine and send them down to John French of JRF Magnetics in New Jersey – he’s the legend as far as saving tape heads. For illustrations and further information about heads and relapping, visit JRF Magnets . If it’s too late for relapping, then replacement heads are the ultimate step, but that’s considerably more expensive. The Tape Path The tape guide roller of a Studer A820. Next, take a look at the tape path: the reel spindles, incoming guides, impedance rollers, capstans, tach roller, tension arms/rollers, lifters and pinch roller. Reel Spindles: hold and secure the reels of tape on the machine Incoming and Outgoing Tape Guides: provide proper positioning of the tape across the heads Impedence Roller: smooths the tape as it comes off the reel before reaching the heads (See “Image 1″ in the gallery following the article) Lifters: guides that pull the tape away from the heads in fast wind modes to prevent unnecessary wear on the heads. Lifters can also be released for fast wind audible cue. (See “Images 2 & 3″ below) Capstans: provides the precise speed to drive the tape past the heads. Rotational speed and diameter of capstan shaft determines the speed. Most capstans shafts have a dull finish. When they become too polished or shiny, they may cause tape slippage and speed errors. The capstan should be able to be rebuilt or refinished by a specialized motor rebuilding service. One such company is MDI Precision Motor Works. NOTE: There are two disclaimers to the polished finish “rule” about capstans. There ARE some designed to be polished or shiny. The best way to determine if your machine’s parts were designed as such is to check the entire length of the shaft. If it is uniformly polished, it is probably designed to be so. Other capstan shafts are made from ceramic material and wear out very slowly, if at all. They are white in color. Pinch Roller: rubber roller that provides proper tension to the tape against the capstan, permitting tape to draw off the supply reel and past the heads at a constant speed. If the pinch roller becomes gummy or cracks, it should be replaced or rebuilt. One of the rebuilding companies I use is Terry Rubber Rollers. Tach Roller: (found on more advanced machines) Used for tape read-out/time counter and also monitors the direction of the tape and its speed for transport control. (See “Image 6″ below) Rotating components in the tape path (guides, impedence rollers, tac rollers, lifter rollers) can have noisy bearings. To test for this problem, you should put a recorded tape on the machine and listen. If you detect noisy bearings, they may need to be replaced. Luckily, many of these parts are shared by a wide range of machines, so they are readily available through many companies that make bearings. The Motors In a tape machine, you’ve got the capstan motor, supply motor, and takeup motor. From a Studer A820: The underside of the reel motors, with an MDA motor driver and electronics below. Reel Motors (Supply & Take Up Motors): controls the reel play out of each reel and provides proper tension across the tape path and heads. It’s easy to tell if you have problems here. They either work or they don’t. If you encounter motors that do not work, they could have worn out or burned out. Either case, they need to be replaced or rebuilt. On newer decks, the motors are driven by a motor drive amplifier (MDA, for short) and this amplifier can fail, preventing the motor from operating. The only way to make this determination is through component level troubleshooting by a skilled technician. Capstan Motor: the most critical motor in the machine. If it is not working properly, the tape will not move properly across the heads, you may hear flutter or other unusual noises when listening to a tape. The best tests include using an alignment tape to distinguish if the tones are steady. Using a piano recording is also a critical way to test for flutter. Keep in mind that if one of the motors isn’t turning, the motor itself may not be bad – it may be the circuitry. The drive electronics may not be happy. The only way to test for this is through component level trouble shooting performed by a skilled technician. Other Rubber Parts Rubber parts are prone to stretching, drying out and crumbling or even turning into a liquid black goo, depending on how they were treated. Urethane parts can turn into a white-colored liquid goo. This is particularly of note to those tape machines using the indirect drive of capstan. In other words, a machine that uses a motor to drive a belt/flywheel containing the capstan shaft. The belts are made of rubber and should be replaced if any of the conditions described above are present. Some Ampex and Otari multitracks use a servo system that employs capstans only and no pinch roller. On these machines, the capstan rollers are made out of rubber or urethane and can experience the same problems described above. However, they can be rebuilt in most cases. There are also some parts of braking that use rubber which should be checked, as well. Most machines do NOT use rubber brakes, but those that apply can be found under the deck plate by the reel spindles or motors. Speed Just to review the basics, tape machines record at different speeds, the higher the speed, the better the quality of the recording. The measure is IPS or inches per second of tape that passes across the record head. Obviously, the faster the tape speed, the more tape that is used to record the performance, so there are financial considerations in determining the speed at which you want to record. Speeds range from 15/16ths IPS (which is only used for low quality voice recordings and logging) up to 30 IPS for the highest quality analog music recording and mastering. If you are doing any serious recording or mastering you will only want to record at 15 IPS or 30 IPS. 7 ½ IPS is the lowest speed considered for “professional” use, but it was limited in use. In the past, radio stations used it as a way to save tape and it was considered the top speed for home recording use. However, it was only used in professional audio recording for making dubs to give to clients to play at home or for radio station use. There are machines that record at 1 7/8ths IPS and 3 ¾ IPS. Besides reel-to-reel machines, cassettes were recorded at 1 7/8ths IPS. The much maligned 8-track cartridge was recorded at 3 ¾ IPS and this speed was considered to be a good voice recording and background music recording speed for home reel-to-reel use. Track Width The wider the track, the quieter the tape and the hotter the signal that can be recorded onto the tape. The tape width determines the amount of tracks you can record on a tape and still maintain excellent quality. Two-track recordings are stereo mix-downs and should be recording on either ¼” or 1/2” formats, depending on your budget. If you are doing multi-track recording on an analog professional format, there are the following choices: =1/2” four track =1” eight track =2” sixteen or twenty-four track There are also semi-professional formats as follows: =1/4” four track =1/4” eight track =1/2” eight track =1/2” sixteen track =1” sixteen track =1” twenty-four track There are some 1” two track machines used for mastering, but they are very exotic and extremely expensive to operate. They are specially modified headstacks installed on professional two track machines. So, the faster the tape speed and the wider the tape, in general, the better the quality of the recording, but, also, the more expensive the cost of tape. At 30 IPS, a standard 2500 foot reel of tape will only provide a little over 16 minutes of record time. Depending on the width of the tape, the tape costs range from $50-300 per reel, or more. (Note: Tape costs fluctuate greatly). Updates The software version display on a Studer A820. On professional studio machines, manufacturers generally released updates to improve performance. Some lesser quality machines might also have upgrades if the original owner turned in the warranty card and paid attention to service update advisories. For example, if you purchased a Studer A80 made in 1978, there were manufacturer updates up until the late 1980s, which included things as important as changing the heads, so you may be lucky enough to find a machine that has been updated on a regular basis. At the big studios, such as Power Station, we would get calls in the Technical Maintenance Department from Studer, Sony, and Ampex letting us know of updates, “We have an update. Can we send a tech over to update all of your machines?” Everything would be kept in their files and the manufacturer kept track of which machines were eligible for updates and when. The update could be something as simple as a resistor value where they would say, “This update will make your deck sound better.” You can check to see if a machine has been upgraded by looking for a little sticker in the machine which indicated the version. If it’s a later machine with microprocessors, then you can look in the service manual and it will say that this microprocessor was put in from “x” serial number to “y” serial number. Or you can check online, there are still websites that cater to these machines. Some decks, like the Studer A820 (pictured) will provide the software version in the menu display when powering up. Service records for machines are a rare commodity. The largest facilities kept logs for all of their equipment, but most of the analog reel-to-reel machines were taken out of service some time ago and most of those records are no longer available. Plus, many of the machines have changed hands a number of times and the current owners never thought to request any of the past service records or notes. On rare occasions, you may be lucky enough to find that meticulous owner. I actually knew the Media Sound and Power Station machines individually, and have recognized one or two of the Media Sound machines when we’ve met again in a different studio, but that only comes from spending many years with my hands inside the guts of the machine. Rebuilding/Restoration A recapped example of an audio card — the dark blue cylinders are replacements. Due to the nature of electrolytic capacitors, there is a tendency for them to dry out, resulting in degraded audio quality due to the fact that their values shift. Therefore, one of the currently popular topics is replacing these capacitors (“recapping”) in audio electronics and power supplies. I doubt that the manufacturers ever thought we would be still using some of this equipment over a period of more than 40 years, so the capacitors are just plain getting old. Old microphone pre-amplifiers and consoles are very popular purchases today, and I spend a lot of time recapping them and the same thing applies to the electronics on analog reel-to-reel tape decks. These older workhorses are often in need of new electrolytic caps. So, when you are investigating the purchase of a machine, ask questions about whether they replaced any of the capacitors during routine or emergency maintenance. If not, you should budget for this expense. Capacitors are components found on the circuit board inside the tape machine. Most people cannot check out the condition of the caps themselves because it requires test equipment to measure the value of each component. There were some pieces of electronic gear that were known to have bad capacitors from the time they were new. But most of those capacitors will have already been replaced by the time you would acquire it second-hand, unless it was barely used. Unfortunately, there are not many resources available to provide in-depth technical information about these vintage tape decks, consoles or other pieces of great gear since so many of the manufacturers are out of business, the machines were often custom-made for the purchasing studio, and they were often not widely produced. However, you can check out a few of the online discussion groups that people have created for individual brands: Studer, Ampex, Otari, Scully, and others. If you know that a piece of electronic gear has not received any maintenance in the past 20 years, you should count on having to replace capacitors. Basic Maintenance Say you take the plunge and buy a tape machine, or you’ve already got one, there’s day-to-day maintenance you should do. I don’t mean pulling out the test equipment and doing an overhaul – just regular maintenance associated with normal usage. For keeping the tape heads and the tape path clean, use 91% or better isopropyl alcohol with Qtips – either wooden stick Qtips or regular Qtips. Dip your Qtip in the alcohol, clean the guides, the heads, the capstan. You want to keep your machine clean! Especially if you’re playing back a lot of old tapes with sticky shed problems. But then you may want to be baking tapes, which is a topic for a whole other conversation. The heads should be demagnetized once a week if you are using the deck regularly. I recommend one made by R.B. Annis called the “Han-D-Mag”. You can find them on eBay or a Pro-Audio vendor like Sweetwater or John French at JRF Magnetics. The last time I looked they were less than $100 new. The instructions are on the package. It’s an easy DIY procedure. The motors should be oiled from time to time….once a year or every six months, depending on use, using what the manufacturer specifies. DO NOT USE 3 In 1 Oil!! Keep the outside of the machine clean as well. Use a damp cloth to remove dirt, dust, and grime. Cover the machine when not in use, but only when the power is off. You should also purchase a MRL (Magnetic Reference Lab) Calibration Test Tape. This tape with tones on it allows you to setup your recorder to standard operating levels. If your tape is played on other machines that were setup with the test tape, it will playback correctly. You should record test tones on the beginning of your masters if you send them out for mastering, 1khz, 10khz, 15khz, 100hz and 50hz. Tape Costs and Tape Types One of the most frustrating things about analog recording in the past five or so years has been the lack of availability of magnetic tape, and the tape that is available is expensive. Right now, we only have two companies manufacturing magnetic tape. RMG, which is really now known as Zonal, is a company located in Holland, but manufacturing their tape in France. The other company is ATR, which is located right in the U.S. of A. in Pennsylvania, and is owned by Mike Sptiz. The quality of the two manufacturers is similar, both are professional grade. But be aware that, historically, magnetic tape has been known to have a “bad batch” now and then. Most manufacturers will exchange bad product for new if you make them aware of the situation. Tape can be reused multiple times unless it has been damaged or spliced. However, you do not want to re-record on tape that is sticky or shedding, which is a problem found with certain brands of tape. Some include Ampex 456 and 406 (the Quantegy 456 was generally OK), Scotch 226 was also notoriously bad for sticking and shedding. Professional Support Tape machines are complicated electromagnetic devices, which require servicing. Unless you know what’s going on in the machine, it’s best to call a pro. If you want something aligned, just call us. We’re here to keep the machines going, because no one is making them anymore. Maintenance is a necessary evil – there’s not that much stuff out there that’s 20 years old that people want to use, but if it sounds good you’ve got to keep it going. Guitar amps are a great example of ancient technology still being made today. So you need a tech guy to check out a machine beforehand and after you acquire one, and nine times out of ten the guys working on your tape machines can fix the rest of your equipment too. For mixers, Pultecs, limiters, you’re tapping into a lot of knowledge from these people. There’s not a lot of us, but we’re still around and brave enough to stay in this business! Midnight Bob Shuster is located in Metro New York and can be found at http://www.shustersound.com. The full underside of a Studer A820 deck. Image 1: A Studer A820 impedance roller. Image 2: The tape lifter retracted on a Scully 280. Image 3: The tape lifter out, on the same Scully. Image 4: A ceramic capstan and rubber pinch roller from a Tascam machine. A standard metal capstan and rubber pinch roller, from a Scully. Image 6: The tach roller of a Studer A820. The tension sensor from a Studer. Tape thyself.
  11. Не мисля, че е добра отправна точка да се стартира от операционната система. На първо място трябва да се преценят възможностите за конкретните измервания, които ще се извършват. Методите и принципите, които ще се използват от програмата/мите. И разбира се цената. Може естествено да се мине с пиратско копие, но това си има своите недостатъци. Направи си списък с нещата, които трябва да се мерят. Ориентирай се какви методи са най-сполучливи за тях. След като се прецени оптималната комбинация от възможности, чак тогава може да се търси конкретно решение, което да изпълни изискванията. Аз не бих започнал от края. (Имайки дългогодишен, професионален опит с електроакустически измервания, мога да предложа първоначално персонално обсъждане и запознаване с особеностите на подобен вид измервания. Знаеш как да се свържеш.) ПП. Софтуерът е само част от системата за измерване. Хардуерът е много важен. За измервания , качествата му са определящи. Не може да е ниско до средно, а само най-високо качество. Иначе няма да мериш, а ще се гъбаркаш .
  12. Lee Ritenour & Mike Stern with The Freeway Band - Live at The Blue Note Tokyo 2011 Track list: - Interview with Lee Ritenour & Mike Stern 1. Freeway Jam 2. Lay It Down - Interview with Mike Stern 3. Wing and a Prayer 4. Etude - Interview with Lee Ritenour 5. All You Need - Interview with Melvin Davis 6. Smoke 'n' Mirrors - Interview with Simon Phillips 7. Double Nickel - Interview with John Beasly 8. Big Neighborhood Musicians: Lee Ritenour - Guitar Mike Stern - Guitar Simon Phillips - Drums John Beasley - Keyboard, Synthesizer Melvin Davis - Bass https://youtu.be/Ho9kdWAvGOM
  13. Stanley Clarke - Lopsy Lu (at the 1976 Downbeat poll-winners' show) Stanley Clarke - b Jean-Luc Ponty - v Chick Corea - p Billy Cobham - dr
  14. Fender Rhodes Stage Piano Mark I - History and Price Guide BY JULIAN COLBECK February 1, 2002 Produced: 1970-79 Made in: United States Designed by: Harold Rhodes Number produced: more than 100,000 System: hammer action, electric pickups Price new: $500-$1,800 Today's prices: Like new $750 Like, it's okay for its age $500 Like hell $300 The Fender Rhodes electric piano possesses one of the most recognizable sounds in modern music. The Rhodes' popularity has waxed and waned over the decades since its introduction, but its sound is still in vogue today in Beck's rock, Brand New Heavies' funk, Chick Corea's jazz, and even in Emagic's EVP88 and EVP73 virtual electric-piano plug-ins. The Rhodes piano was the brainchild of musician Harold Rhodes. While a flying instructor stationed in Greensboro, North Carolina, Rhodes designed his first portable acoustic piano for the U.S. Army Air Corps in 1942. Beginning with a pile of aluminum tubing salvaged from a B-17 bomber, Rhodes fashioned a sort of xylophone with a 29-note keyboard. Following World War II, Rhodes built a self-amplified, 38-note electric model called the Pre-Piano after taking apart a chiming clock that used spun-metal rods called tines. At the 1959 NAMM convention, Rhodes introduced the Piano Bass, which was later enthusiastically embraced by Ray Manzarek of the Doors. Of all the models to emerge over the years, however, perhaps the best known and most desirable is the 73-key Fender Rhodes Stage Piano Mark I. Introduced in 1970, the 132-pound Mark I is made of wood, covered in a fabric-reinforced vinyl called Tolex, and sized to fit into a box that measures 45.25 by 9.85 by 23.63 inches. A compartment in the top cover houses four telescoping tubular steel legs that screw into the instrument's underside at a splayed angle for sturdy setup. A long metal sustain pedal attaches to the keyboard mechanism through a small hole in the center of the piano's underside via interlocking rods. Unfortunately, the pedal arrangement has always been difficult to fit and invariably slackens or falls out in the middle of a gig. The original Stage Piano's control panel is sparse, with a volume knob, a tone knob, and a stereo ¼-inch TRS output jack. The Mark I's Bass Boost is a passive tone control, though some of the later models offer active tone control. The curved, sloping lid makes it impossible to stand your beer, sheet music, or another instrument on top without the framelike contraption that was seen occasionally in the 1970s. The Mark I was manufactured in 73- and 88-key models. On the early Mark Is, the hammers were made of felt-covered wood; they were replaced on later models by rubber-covered plastic. Sound is generated when the key action causes the hammers to strike the tines. Audible vibrations are picked up by a system of individual magnets positioned close to the tip of each tine. With keys that are slightly shorter and narrower than standard piano keys, a typical Rhodes piano began life with a wrist-breakingly stiff action. The weighted keys usually took months to loosen up and settle down; most became knackered — a term commonly used among Rhodes players — in their first year or so. Accordingly, no two instruments feel or sound quite the same. Some are a pleasure to play, and others are simply murderous. The classic Rhodes sound is highly expressive — part bell, part xylophone, and part piano. With its relatively soft, muted tones and brilliant dynamics, the Rhodes piano is especially well suited to the subtleties of jazz. Hitting a note really hard produces anything from a harmonic or a dull thwack to a clear, loud, crystalline tone. Two hardware pieces that greatly influence the Rhodes sound are the amplifier and the effects processor through which the piano is played. Shortly after the Mark I's introduction, the Fender Twin Reverb established itself as the amplifier of choice, in part because of its appropriately moody tremolo. The Roland JC-120 Jazz Chorus is also an excellent choice for amplification, especially with its creamy built-in chorus effect. Before the JC-120, players had to rely on chorus and phaser pedals that were notoriously noisy and ate batteries for breakfast. Still, if you want the authentic feel of the '70s, you may opt to take the stompbox route. Rhodes pianos were produced in large quantities, and they're still in plentiful supply. Bargains abound, and with a little patience and skill, you can perform most repairs yourself. If you want to hear, see, and feel how musical instruments were before digitization made everything virtual, a Rhodes presents the lesson perfectly. Before you purchase a Rhodes, give it an aural and a physical examination. Keyboard action is a matter of personal taste, but an action that's too loose is probably on its way out. Don't be overly concerned with the evenness of the tone or the loudness of individual notes; both are easy to correct by adjusting the angle or distance between the tine and the pickup. You should be aware that during the late '70s, then-owner CBS substituted some of the original construction materials, resulting in an instrument with a tone that Harold Rhodes considered inferior to earlier and later models. With the exception of the tines, which break frequently, the Rhodes is fairly maintenance free. Fitting and replacing tines is laborious rather than difficult and requires nothing more than a screwdriver, a pair of pliers, reasonably good eyes and ears, and a steady hand. Each tine is cut to an approximate length and then fine-tuned by scraping tuning springs along its length. You can obtain replacement parts from a huge variety of sources, and third-party modifications have always been available. From the mid-'70s until the mid-'80s, the most popular mod was Chuck Monte's Dyno-My-Piano, which employed mechanical and electronic makeovers to make the Rhodes sound even brighter and more bell-like. Plenty of resources are available on the Web, but nothing comes close to the Rhodes Super Site www.fenderrhodes.org. There you'll find online versions of the original brochures, user guides, and service manuals for various models, as well as fascinating historical information, FAQs, classified ads, and a lengthy list of repair facilities. Although the Fender Rhodes itself has gone in and out of fashion, digital emulations of its sound have remained popular since the age of the Yamaha DX7, which for many players provided a most effective substitute. During the late '80s, when the Rhodes piano reached the height of unfashionability, I abandoned mine beneath a friend's house. Harold Rhodes died on December 17, 2000. He was much more than an idiosyncratic keyboard inventor, but he remained fiercely proud of his robust family of electric pianos, and with good reason. The Fender Rhodes piano is assured a place in musical history, and it remains a viable force in today's music. Go play one and you'll discover why. Julian Colbeck has toured everywhere from Tokyo to São Paulo with artists as varied as Yes, Steve Hackett, John Miles, and Charlie. PRICE GUIDEThe QUOTEd prices reflect typical street prices you must expect to pay in U.S. dollars. The buy-in on vintage instruments, as with vintage cars, is just the beginning, though. Most of the original manufacturers are long gone, so maintenance and repairs are expensive.
  15. Pete Townshend Records Direct To Vinyl Nashville, TN (June 9, 2015)—Welcome to 1979, a retro-oriented studio in Nashville, recently hosted musician and philanthropist Pete Townshend of The Who for a three-day weekend before The Who Hits 50 Tour rolled into Music City. While there, he recorded directly to a vinyl master to create a unique, one-off record to be auctioned for charity. Pete’s sessions were recorded two ways—one with a custom MCI 2 8 track (refurbished by 79’s sister company, Mara Machines), and then directly to the studio’s vinyl lathe. During a special benefit concert in Chicago on May 14th, Pete revealed a one-of-a-kind record that he recorded during his sessions at Welcome To 1979—an exclusive version of “I’m One” from Quadrophenia. In 2012, Townshend and bandmate Roger Daltrey founded Teen Cancer America— a charity aimed at youth-oriented treatment and rehabilitation centers for teenagers and young adults. The 12-inch single Pete recorded at Welcome to 1979 was one of two featured items being auctioned off to benefit the non-profit organization. For a $25 dollar donation, individuals were entered into a drawing for the chance to win the exclusive single. The weeklong auction produced $37,000—all of which benefits Teen Cancer America.
  16. This is what $20k got you in 1952 - for Democratic & Republican National Conventions - Jensen G610s, custom Conn horns.
  17. "It’s amazing. This guy is 71, partied hard all his life and yet Dave Grohl is the one in a wheelchair!"
  18. “The Godmother of Rock and Roll” - Sister Rosetta Tharpe Rosetta Tharpe plays 'Didn't It Rain'. Recorded in Manchester, England in 1964. https://youtu.be/SR2gR6SZC2M Sister Rosetta Tharpe: That's All https://youtu.be/l9bX5mzdihs The Story Of Sister Rosetta Tharpe 01 https://youtu.be/RuVzm86oB1Y The Story Of Sister Rosetta Tharpe 02 The Story Of Sister Rosetta Tharpe 03 The Story Of Sister Rosetta Tharpe 04
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