HIGH FIDELITY, PROFESSIONAL GRADE MICROPHONE SYSTEM FOR DIRECT COUPLING TO RECORDING COMPONENTS
20180084325 ยท 2018-03-22
Inventors
Cpc classification
H04R1/04
ELECTRICITY
International classification
H04R1/04
ELECTRICITY
Abstract
Current microphone designs are still using concepts developed in the early 20th century. A transducer followed by a simple buffer with high impedance, low power, and low gain. Even when tubes were replaced by solid state devices the same practice continued, with the low gain triode being replaced by an even smaller power, lower current FET buffer. The invention offers a microphone system intended for professional audio applications that dispenses with these, low power concepts and incorporates elements of a microphone, microphone pre amplifier, and high power mixing console/pre amp line drivers into a single housing. By combining transducer, high fidelity pre amp circuit, and high power line driving stage with a high voltage, high current external power supply, the capabilities of microphones can be greatly increased in many ways. Our approach can be implemented in a variety of circuit topologies including discrete transistors, tubes and integrated circuits, our concept allows microphones to connect directly to analog or digital recording devices without the need for external mixers or pre amplifiers. The design not only allows for unprecedented simplicity in the work flow of the modern recording studio, which combines the use of stand-alone analog records, standalone digital recorder, and computer workstation based recording options, but also eliminates redundant circuits that are present in microphones, microphone pre amps, and mixing consoles, while offering the customer increased value.
Claims
1. A high fidelity microphone comprising: a. a microphone capsule to transduce sound from acoustic energy into an electrical signal; b. instead of a high impedance, low power, low gain buffer of the capsule electrical signal to an output stage connectable to an external preamp, an internal pre amp high fidelity circuit comprising: i. a high power, mixing console pre amp line driver stage ii. connectable to an external high voltage, high current external power source; iii. an output stage comprising a high fidelity connector adapted for connection to any of: 1. analog recorder; 2. digital recorder; or 3. external mixing console.
2. The apparatus of claim 1 wherein: a. a transformer is not used between the capsule and the pre amp stage.
3. The apparatus of claim 1 wherein is the internal pre amp high fidelity circuit provides approximately 30-40 dB of overall voltage gain.
4. The apparatus of claim 1 wherein gain is spread relatively evenly between the pre amp stage and the line amp stage.
5. The apparatus of claim 1 wherein the pre amp stage functions as both a buffer and a variable gain amp.
6. The microphone apparatus of claim 1 wherein the acoustic capsule and high fidelity circuit are integrated.
7. The microphone apparatus of claim 6 wherein the integration comprises housing the components in a hand-held size microphone housing.
8. The microphone apparatus of claim 7 further comprising one or more of: an output fader in the housing and an output transformer.
9. The microphone apparatus of claim 1 wherein the pre amp and line driver stages comprise analog tubes.
10. The microphone apparatus of claim 9 wherein the analog tubes comprise a pentode and a triode respectively.
11. The microphone apparatus of claim 1 wherein the pre amp and line driver stages comprise integrated circuits.
12. The microphone apparatus of claim 11 wherein the pre amp and line driver stages comprise field effect transistors (FETs), and discrete transistors.
13. The apparatus of claim 1 wherein: a. the pre amp stage produces gain amplifier voltage comprises relatively high voltage and high current; b. the line driver stage produces line amplifier voltage comprises relatively high voltage and high current.
14. The apparatus of claim 13 wherein the relatively high voltage, high current comprises sufficient to effect high fidelity.
15. The apparatus of claim 1 wherein the internal gain amplifier is within inches of the acoustic transducer in the signal path.
16. The apparatus of claim 1 wherein the high fidelity circuit provides: a. an output signal sufficient for modern analog recorders; b. an output signal sufficient for modern digital recorders; and c. an output signal sufficient for modern mixing consoles.
17. The apparatus of claim 1 wherein the high fidelity connector comprises a cable having a length of inches to feet to hundreds of feet.
18. The apparatus of claim 1 wherein the microphone housing has a form factor on the order of: a. one foot long; b. a few inches wide.
19. The apparatus of claim 1 wherein the internal pre amp comprises one of a tube component, an IC, or a discrete solid state device.
20. The apparatus of claim 1 applied to a plurality of said microphones for a given audio event including: a. live performance amplification; or b. recording via analog or digital recording component.
21. A method of recording music comprising: a. transducing the music at a microphone location into a signal path; b. instead of a high impedance, low power, low gain buffer of the capsule electrical signal to an output stage connectable to an external preamp, an internal pre amp high fidelity circuit comprising: i. a high power, mixing console pre amp line driver stage ii. connectable to an external high voltage, high current external power source; iii. an output stage comprising a high fidelity connector adapted for connection to any of: 1. analog recorder; 2. digital recorder; or 3. external mixing console.
22. The method of claim 21 wherein impedance is kept high or very high regardless of circuit topology wherein examples of circuit topology include: a. tube based; b. integrated circuit based; or c. discrete solid state component based.
23. The method of claim 21 wherein high gain is provided by one of selected circuit topologies that are operatively connected to an external dedicated power supply of relatively high voltage/high current availability.
24. The method of claim 21 wherein the relative gain is on the order of 10-40 dB for proper interfacing with the capsule, adequate gain, and line level high quality interfacing with recording components.
25. The method of claim 21 wherein: a. gain is spread out substantially evenly between pre amp and line amp functions in the mic housing; b. impedance is high or very high compared to conventional mics; and c. output current is high.
26. The method of claim 25 wherein for tube based topographies comprise: a. a typical low again triode is replaced with high gain pentode with very high impedance (e.g. on the order of 1 gigohm minimum) and controllable through negative feedback; a. a dual Pentode in cascade with very high impedance (e.g. on the order of 1 gigohm minimum) and controllable through negative feedback; b. on the order of 30 dB gain is available at pre amp stage: c. on the order of 30 dB gain is available at the line drive stage: d. a valve for the output is run at high current and low voltage; e. the output transformer has reduced impedance so can use the mic as a standard low gain mic or as a high gain mic.
27. The method of claim 25 wherein for IC based topologies comprise: a. a high gain pre amp with very high impedance (e.g. on the order of 1 gigohm minimum); b. on the order of 30 dB gain is available at pre amp stage: c. on the order of 10-20 dB gain is available at the line drive and output stages (approx. 10 dB for the line amp and 10 dB for the output stage); d. a valve for the output is run at high current and low voltage; a. the high output current has adequate swing.
28. The method of claim 25 wherein for discrete solid state component topology comprise: a. a high gain is with a high impedance (e.g. 1 gigohm minimum) FET with DC coupled pair with feedback; b. on the order of 30 dB available gain at the amp stage: c. on the order of 10-20 dB available gain at the line drive and output stages (e.g. 10 dB at line drive and 10 dB at output); d. high current output with adequate swing (e.g. line driver in Class A arrangement).
29. The method of claim 25 wherein gain of 30-40 dB is selected as not too much because of risk of noise, distortion, and feedback.
30. The method of claim 25 wherein gain can be adjusted at the mic.
31. A system for recording audio comprising: a. a microphone stage; b. a recording stage; c. the microphone stage comprising in operative connection: i. an audio transducer; ii. a gain amp; iii. a line amp; and iv. an output transformer; v. external power; d. the recording stage comprising in operative connection to the output transformer of the microphone stage: i. an analog or digital recording system; or ii. a mixing console connected to an analog or digital recording system.
32. The system of claim 31 wherein the components are designed according to one or more rules in claims 25-30.
33. The system of claim 31 wherein the circuit is implemented in a tube based topography utilizing a pentode in a pre amp stage and a triode in a line driving stage.
34. The system of claim 31 wherein the circuit is implemented in an IC based topography utilizing FETs.
35. The system of claim 31 wherein the circuit is implemented in a discrete solid state component based topography comprising transistors.
36. A high fidelity microphone system comprising: a. a housing or capsule comprising: i. an acoustic transducer having an input for converting sound into an electrical signal at an output; ii. a high fidelity pre amp circuit having an input in operative communication with the output of the acoustic transducer, and an output for an amplified signal; iii. a line driving stage having an input in operative communication with the output of the pre amp and an output; b. a first electrical conductor between the pre amp and line driving stage and an output coupling adapted for operative communication with an external high voltage, high current power source; c. a second electrical conductor between the output of the line driving stage and an output coupling adapted for operative communication with a recording device.
37. The apparatus of claim 36 wherein the acoustic transducer comprises a microphone capsule of: a. condenser-type; b. dynamic type; c. electret. d. ribbon
38. The apparatus of claim 36 wherein the capsule is buffered correctly, high gain pre amp circuits provide high power outputs capable of driving any circuit in a modern recording studio.
39. The apparatus of claim 36 wherein on the order of 30-40 dB overall voltage gain is realized while proper interfacing with the capsule, providing adequate gain, and providing line level high quality interfacing with a recording component.
40. A method of transducing audio from a live performance and providing a high fidelity audio signal of the transduced audio along a signal path comprising: a. providing a plurality of microphone assemblies at the live performance, each microphone assembly comprising: i. a single housing containing; 1. a microphone capsule; b. a buffer connected to the transduced audio of the capsule along the signal path comprising c. a high current input amp designed to correctly buffer the capsule and provide on the order of 20 dB gain; d. a line driver and a output stage to provide on the order of 20 dB gain; e. a cable from the housing comprising 1. a connection of the preamp and line driving stages to a relatively high voltage, high current external power source; and 2. a connection of the microphone capsule, if needed, to voltage of the same nature as phantom power; 3. a connection of the signal path to a. an external analog recording component; b. an external digital recording component; or c. an external mixing console; f. so that external amplifiers are not required between the microphone assemblies and the recording component or mixing console and gain is incorporated at an earlier stage of the signal path from the transducer.
41. The method of claim 40 wherein the buffer is in relatively close proximity (e.g. <inch or so) to the capsule.
42. The method of claim 40 wherein the output stage is in relatively close proximity (e.g. approx. an inch or so) to the buffer.
Description
III. BRIEF DESCRIPTION OF DRAWINGS
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IV. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0077] A. Overview
[0078] For better understanding of the invention, a few examples of forms the invention can take will now be described in detail. As will be understood by those of skill in the art, the invention can take a wide variety of forms and embodiments. The following examples are neither exclusive nor inclusive of all possible forms. Variations obvious to those skilled in the art will be included within the invention which can be applied and fabricated in analogous ways.
[0079] Following will be a generalized discussion of the concept, and then a specific discussion of examples of device fabrication and implementation. Thereafter will be a discussion of some examples of alternatives and options.
[0080] B. Generalized Concept
[0081] 1. Apparatus
[0082] In a generalized sense, the invention relates to a change in paradigm in the state of the art of professional audio microphones. It presents a microphone assembly that can house not only the microphone capsule (of whatever type or form), but also components that allow the assembly to then be plugged directly into a variety of downstream audio handling components without having to customize or reconfigure the assembly. For example, the new paradigm includes a combination of features in a single microphone housing that facilities direct connection to any one of an analog audio recorder, a digital audio recorder, or even at least most mixing consoles. This is counter-intuitive to the state of the art, which requires intermediary external components between microphone and recorder. Aspects of the invention include a selection and balancing of factors, some of which are antagonistic to each other.
[0083] In one example, in general form, the invention can be implemented as indicated at ref no. 70 in
[0084] Our new design eliminates the need for preamplifier pads for loud sources since redundant gain circuits are eliminated, and gain is managed at an earlier stage of the signal path.
[0085] Impedance of the input amplifier should be kept high regardless of circuit topology.
[0086] Our circuit allows for the microphone to be plugged directly into any analog tape recorder, stand alone digital recorder, or computer based recorder, and bypass external the mic-preamp and/or mixing console entirely. It is, however, capable of interfacing with a mixing console, when hybrid mixing systems are in use (a USB microphone could not). For example, analog mixing consoles, stand alone digital recorders, and stand alone digital mixers would not have features to support them. USB ports and the ability to run MAC or Windows OS are required at the minimum.
[0087] One way the generalized invention can be built is as follows: [0088] A single microphone body or housing that contains: [0089] a) a microphone, namely a transducer or capsule; [0090] b) a pre-amp, namely a microphone pre-amplifier; with the ability to adjust overall gain of the unit. [0091] c) a console style fader, namely for volume control, master volume; [0092] d) a line driver capable of interfacing in any professional audio environment; [0093] e) a circuit operatively connecting the microphone, pre-amp, and line driver, and console style fader/volume control; [0094] f) a cord that is connectable to a further component (e.g. recorder or mixer); the circuit uses both an audio cable and a power cable that provides 48 volt phantom power and DC voltage for high power solid state circuits as well as high voltage supplies for tube circuits, and the heaters associated with them; [0095] g) a power source comprising typically a stand-alone external, table top size dedicated power supply; the power source comprises high voltage, high current power supply as used in microphone pre-amps, HiFi audio, and mixing consoles. This allows the microphone to be built with high power (and excellent sounding) amplifiers that will drive long lines at maximum fidelity, instead of using low levels signals that can become susceptible to grounding issues and audio quality degradation. This also allows use of much less circuitry (e.g. transformers or balancing amps; fewer amplifiers).
[0096] Current microphone designs are still using concepts developed in the early 20th century. A transducer followed by a high impedance, low power, low gain buffer. Even when tubes were replaced by solid state devices the same practice continued, but the with the low gain triode being replaced by an even smaller power, lower current FET buffer.
[0097] A comparison of
[0098] The same is true with a comparison of
[0099] Therefore, the invention can include the following types of features and benefits over the state of the art configurations: [0100] a. Improved sonics and decreased tonal degradation as long lines are not needed to connect microphone in the studio to the mixing desk or pre amplifier in the control room. [0101] b. Simplification of signal path, ease of use and highly improved work flow. [0102] c. Shorter signal path for sonics. need for less routing and shorter cable lengths in complicated systems. cost savings to customer who no longer needs to purchase separate preamplifiers or mixers to record professionally. [0103] d. With the correct circuits, you can both buffer the capsule correctly and include high gain pre amps circuits as well as provide high power outputs capable of driving any circuit in the modern recording studio. [0104] e. This application can be used with discrete semiconductors, modern op amps, and even tube designs. [0105] f. High voltage power source provides increased flexibility with circuits used in microphone (see below). [0106] g. Gets rid of redundant circuits that may be present in both a microphone and microphone pre-amp, and mixing consoles. [0107] h. Eliminates the need for external pre amplifiers and/or mixers in a professional environment. [0108] i. Allows for unprecedented simplicity in work flow, being analog, digital, or hybrid recording situations.
[0109] As will be appreciated by those skilled in the art, the new paradigm essentially selects and integrates in a single housing: [0110] 1. Transducer (capsule) from microphone [0111] 2. Gain control as a mic pre amp or mixing console input [0112] 3. Phase reverse control as on mic pre amp and mixing console input [0113] 4. Gain circuit as on mic pre amp and mixing console input [0114] 5. Line driver as on mic pre amp and mixing console outputs [0115] 6. Capsule Pad as on a microphone [0116] 7. Selectable Pickup pattern as on microphone [0117] 8. Output fader as on mixing console
[0118] In contrast, newer attempts in a home or bedroom quality setting of direct-plug-in microphones, such as USB mics, differ in at least the following ways. USB mics cannot: [0119] i. Connect to an analog mixer. Analog mixer would not have the ability to run Mac or Windows OS required by the USB microphone. Would not have USB ports. [0120] ii. Connect to an analog tape machine. Analog mixer would not have the ability to run Mac or Windows OS required by the USB microphone. Would not USB ports. [0121] iii. USB microphones are generally designed as slightly higher quality replacement of the built in mic on a computer. Generally used for podcasts and voiceovers. [0122] iv. Are not designed to professional sound standards. A quick survey of available USB microphones shows that some cannot handle high enough SPLs (sound pressure levels) to accommodate a real world recording environment where loud sources such as drum sets and guitar amplifiers are employed. Also, a number did not even publish this data at the time of application. For reference these phrases are taken directly from marketing information of a known USB microphone [0123] v. Designed for vocal and acoustic instrument recording [0124] vi. Also, great for recording interviews, podcasts, voice overs, and audio for video
[0125] One microphone for sale on a music equipment website is even called the Podcaster. But note the following regarding such microphones.
[0126] USB microphones induce latency. This induces a delay that could not be tolerated in a live application where the vocal, for example, would be perceived to be lagging behind the rest of the instruments. Professional digital systems employ delay compensation within their software to delay all signals by the same number of samples to ensure that all signals are heard in the correct time base. USB microphones are not sophisticated enough to do this.
[0127] Bit Depth. Some (but not all) USB microphones do not function at the bit depth or current professional audio systems which have advanced well beyond the 16 bit/44.1 kHz sampling frequencies of the past. The author could not find a single USB mic that could record at the sample rates available on current professional audio digital recorders which is 24 bit/192kHz.
[0128] Requires Mac or Windows OS to operate. Analog mixers, stand-alone digital recorder, stand-alone digital mixing consoles, and others either do not use an operating system or are systems designed specifically for that product.
[0129] The approach of the invention allows such things as: [0130] a. Approach presentation from a universal perspective that could be applied to tube, discrete solid state, or integrated circuit technologies. [0131] b. Present support for Professional Audio and Live sound applications. Not intended to cover areas of use related to USB microphones. [0132] c. change in amplifier requires manipulating circuit for proper tonal characteristics, and proper selection of capsule (e.g. pentode following capsule may affect tone).
[0133] It can therefore be seen by reference to
[0134] In the comparison of
[0135] 2. Design Criteria/Considerations/Rules
[0136] As previously mentioned, making and using the invention requires consideration of and balancing of a number of factors. Some are antagonistic with one another. Because the invention can take different forms and embodiments, below are some of the considerations and balancing that will inform a designer.
[0137] When undertaking application of the invention (e.g. microphone, preamp, line driver, and fader concept), the designer should consider these elements.
[0138] a. Proper Microphone Design and Condenser Application.
[0139] 1) Change in amplifier requires manipulating circuit for proper tonal characteristics.
[0140] 2) Proper selection of capsule. Generally speaking a capsule would be designed that both compliments the tonality of the circuit being designed but also fulfills requirements for the desired reproduction of sound. Parameters such as capacitance of the capsule, materials for the membrane and sputtering of the diaphragm, and overall design of the capsule backplane must be observed. Suppliers can be found that over generic versions of capsules but the author has found that these are less suited for our improved microphone application.
[0141] 3) pentode following capsule can affect tone. Pentodes have characteristics known to be different than triodes and these are widely documented. Since pentodes, to authors knowledge, have not generally been used in microphone designs these tonal and operation characteristics much be considered, especially when choosing a capsule or transducer.
[0142] b. Design of Pre Amplification
[0143] Since the amplification following the transducer is different than past microphone designs various parameters must be considered. For example, the higher gain pentode used in this approach will have more noise than the triode so structure of gain must be properly applied (see below). In our final tube design, that is attached as part of this document, we were able to obtain noise figures that were well below the authors own designs of stand-alone pre amplifier and microphone combinations, for the reasons outlined in this document.
[0144] c. Design of Power Amplifier and Line Drivers
[0145] Because we are combining both microphone and pre amplifier design into one small unit, we must consider the differences in the two types (e.g. compare
[0146] To that end the designer should follow these rules and application notes (please note these are references to our application using a tube circuit (see
[0147] i. Specific Rules for Tube-Based, Pentode, Version 30 (e.g.
[0148] With particular reference to
[0157] Since standard microphones do not have a line level output driver, one must be designed and added using these parameters. [0158] 1) Line driver 32C has on the order of 30 dB of available gain. [0159] 2) The valve for the output stage 32C is run in a high-current, low voltage condition to allow for adequate current swing at the output. This ensures high headroom and ability to drive any source that may be required in the studio application. [0160] This valve is usually a readily available triode (see
[0161] c. Design of Output Transformer
[0162] The output transformer 32D should be thought of as a combination of a microphone output and as a typical line level valve output. Generally, it will be a step down transformer with a loss of around 20 dB, but varying based on the impedance needed to match the tube chosen for the line driver. Our application uses a mixture of a standard tube line stage but with the lower 200 ohm output of most microphones. The 200 ohm output allows for variation in its use as well as lowering the noise floor. Since the output of the overall circuit is 200 instead of the standard 600 ohms, the unit can be used as a standard low gain microphone, by setting the feedback to maximum, or as our high gain microphone with pre amp application with variable gain. Therefore, it increases the useful range of the microphone 30 even further beyond that of a typical microphone, as it can be used in either application. Output fader 32E can be included.
[0163] i. Specific Rules for Tube-Based, Triode, Version (e.g.
[0164] A dual triode design using a single dual triode tube such as a 12zx7, allows a simpler, more cost effective, easier to design, and lower heat application in this embodiment 40 of the invention in
[0173] Since standard microphones do not have a line level output driver, one must be designed and added using these parameters. [0174] 1) Line driver 42C should have 30 dB of available gain. [0175] 2) The valve for the output stage is run in a high-current, low voltage condition to allow for adequate current swing at the output. This ensures high headroom and ability to drive any source that may be required in the studio application. This valve is usually a readily available triode of the type typically used in high quality HiFi applications such as a 6CG7, 6DJ8.
[0176] e. Design of Output Transformer
[0177] The output transformer 42D should be thought of as a combination of a microphone output and as a typical line level valve output. Generally, it will be a step down transformer with a loss of around 20 dB, but varying based on the impedance needed to match the tube chosen for the line driver. Our application uses a mixture of a standard tube line stage but with the lower 200 ohm output of most microphones. The 200 ohm output allows for variation in its use as well as lowering the noise floor. Since the output of the overall circuit is 200 instead of the standard 600 ohm, the unit can be used as a standard low gain microphone, by setting the feedback to maximum, or as our high gain microphone with pre amp application with variable gain. Therefore, it increases the useful range of this embodiment of the invention even further beyond that of a typical microphone, as it can be used in either application. An optimal output fader 42E can be implemented as shown.
[0178] i. Specific Rules for Integrated Circuit-Based Version (e.g.
[0179] Generally speaking, discrete transistor and IC based designs can follow similar procedures. For the sake of showing how our design approach can be implemented in a number of varieties, the drawing and description for each circuit type are shown with their own variations.
[0180] Integrated Circuit [0181] 1) Gain should be spread relatively evenly between pre amplifier 42B (parts 1 and 2) and line amplifier 42C stages. [0182] 2) Input amplifier 42B is shown with a different possible variation that combines of FET buffer transistor with Integrated Circuit gain amplifier. [0183] a) As in the tube circuit example, the impedance is kept extremely high to avoid loading the capsule and to avoid unwanted interaction with the gain control and capsule in general. On the order of 1 gig ohm should be considered minimum. [0184] b) Pre amplifier 42B should have up to 30 dB of available gain.
[0185] Since standard microphones do not have a line level output driver, one must be designed and added using these parameters. [0186] 1) Line driver 42C and output transformer 42D combination should have 10-20 dB of available gain. Design should be such that correct gain and headroom are achieved with lowest noise. [0187] a) Because sold state designs generally do not use step down transformers on their outputs (as do tube circuits), less amplifier gain is needed for the line stage. On the order of 10 db gain for the amplifier 42C and 10 dB step up for the transformer 42D would generally be considered more than adequate. [0188] b) 200 ohm output is preferred to typical 600 ohm to allow for the variation and flexibility as outlined under tube versions. Generally speaking a 4 dB step up transformer will then be preferred for proper balance of headroom and noise characteristics. [0189] 2) As with the tube circuit a high current output section 42D with adequate swing is required. [0190] a) Our example shows an integrated circuit input section with a complimentary pair of output devices to add additional power and improve sonics of the standard operational amplifier.
[0191] ii. Specific Rules for Solid State-Based Version 50 (e.g.
[0192] Discrete Transistor [0193] 1) Gain should be spread somewhat evenly between Pre Amplifier 52B and Line amplifier 52C stages. [0194] 2) Input amplifier 52B should combine both buffer and gain sections and should also have variable gain as on a pre amp, as described below. [0195] a) This example (
[0198] Since standard microphones do not have a line level output driver one must be designed and added using these parameters. [0199] 1) Line driver 52C and output transformer 52D combination should have 10-20 dB of available gain. Design should be such that correct gain and headroom are achieved with lowest noise. [0200] a) Because sold state designs generally do not use step down transformers on their outputs (as do tube circuits) less amplifier gain is needed for the line stage. 10 db gain for the amplifier 52C and 10 dB step up for the transformer 52D would generally be considered more than adequate. [0201] b) 200 ohm output is preferred to typical 600 ohm to allow for the variation and flexibility as outlined under tube versions. Generally speaking a 4 dB step up transformer will then be preferred for proper balance of headroom and noise characteristics. [0202] 2) As with the tube circuit (
[0204] Optimal fader 52E is shown, as is pre amp gain control 200.
[0205] C. Specific Example 1 (Tube-Based) (
[0206] With reference to
[0207] 1. Input Stage
[0208] A sound transducer or capsule 32A is selected. This can be any of a number of off-the-shelf, commercially available capsules. Examples are: A high quality historically accurate replacement transducer is available from Thiersch Elektroakustik. http://www.thiersch-mic.de/en/estm_service_cap_bl.html. The mic level signal from the transducer 32A is fed to the high gain pentode 32B and medium gain triode 32C prior which produces a line level signal that is output from the mic housing 33 through an isolating transformer 32D.
[0209] External power for pre amp voltage to the pentode and line amp voltage to the triode can be from an external dedicated power supply (schematically shown at ref no. 17A) through separate pin connectors or conductors. An example of a possible external dedicated power supply is as follows. While it is recommended that transformers and power supplies be designed specifically for each project, versions of these items can be sourced fairly easily. For tube versions of our application the power supply must be constructed to match the voltage requirements of the chosen tubes. This can be done easily by using an off the shelf transformer (e.g. Hammond Power Solutions of Baraboo, Wis., USA is one supplier) in combination with a simple pass transistor for the mains and a basic regulator arrangement for the heaters. For solid state and IC versions of the circuit, however, off the shelf power supplies ranging from standard open frame power supply modules to high current wall warts such as these can be used: [0210] (1) http://www.mouser.com/ProductDetail/Mean-Well/EPP-300-48/?qs=sGAEpiMZZMs2%252bVrH5rwl1mWOmnbgLiPQGpRWZHwoQM0%3d. [0211] (2) http://www.mouser.com/ProductDetail/Ault-SL-Power/TE20A4803B01/?qs=sGAEpiMZZMs2%252bVrH5rwl1kCa5Dr%252b EJuvl8MzUNZDXOuuNC%2fpLgohzA%3d%3d.
[0212] If needed, the equivalent of phantom voltage to the capsule is provided by a dedicated capsule voltage line (e.g. 48 VDC) from that same external power supply 17A.
[0213] A reference line is indicated in the thicker black line in
[0214] 2. Buffer Stage
[0215] The buffer 32B and line driver 32C can be implemented with analog tube components. In this example, the buffer stage 32B includes a high gain pentode as a high gain amplifier. As shown in
[0216] Pentodes are electronic amplifying vacuum tubes or valves. Pentodes can have higher current outputs and a wider output voltage swing than tubes such as tetrodes and triodes.
[0217] As a general rule, this stage receives a relatively low level electrical signal from the capsule. The buffering is basically to minimize effects of the amplifier stages on the capsule. The pentode provides high gain (e.g. an EF86 pentode has a gain factor of 38).
[0218] The pentode is powered by external power 71A (e.g. suitable voltage range will depend on the pentode of your choice. For example, a 6AK5 pentode call for a plate voltage of 120-180 volts at 7.5-7.7 mA and 6.3 volt heaters at 175 mA) via a dedicated pre amp voltage line. One example of a possible pentode is Model No. 6AK5 from TubeDepot. http://www.tubedepot.com/products/5654-6ak5w-6096. Line Driver Stage
[0219] The line driver 32C can also be implemented with analog tube components. In this example, it includes a medium gain triode. Triodes are electronic amplifying vacuum tubes that can be applied to provide power gain at audio and radio frequencies. Additional circuit components (e.g. resistors, diodes, capacitors, etc.) can be configured to produce the desired line driving function of this stage (see
[0220] As a general rule, this stage receives an amplified signal from the pre amp stage 32B and provides further gain to enable relatively high voltage, high current driving of the output signal. This triode provides medium gain (e.g. for example a 6CG7 tube has an amplification factor of 20) as a relative matter and is powered by external power (e.g. suitable voltage range will depend on the triode of your choice). For example, a 6CG7 triode calls for a plate voltage of 50-250 volts at 9-10 mA and 6.3 volt heaters at 600 mA) via a dedicated line amp voltage line. See
[0221] One example of a possible triode is Model No. 6CG7 from TubeDepot. https://www.tubedepot.com/products/electro-harmonix-6cg7-6fq7-eh-preamp-vacuum-tube.
[0222] Note that in this example, a rheostat or equivalent (see caption microphone gain and ref no. 200) allows some range of manually-controlled variation of gain by use of feedback from the output of the line stage to the cathode of the gain stage.
[0223] This stage is called medium gain because triodes tend to have less gain the pentodes and tube are usually represented as high-gain (or high-mu) or medium gain (or mu) etc.
[0224] 3. Output Stage
[0225] An output transformer 32D and optional fader 32E are used to electrically isolate the output signal match impedances to equipment following, isolate, create or adjust tonality, is part of the overall gain scheme of the unit respectively.
[0226] One example of a possible transformer is Model No. 4935 from Sowter Transformer of Ipswich, England. One example of a possible fader is Model No. 380C25000 from Honeywell, USA.
[0227] 4. Housing, Cabling, and Connectors
[0228] As diagrammatically illustrated in
[0229] Cables can be XLR to XLR, TRS to TRS, XLR to TRS, etc.
[0230] As can be seen, the specific embodiment of
[0231] Even though tubes have generally been eclipsed by ICs and solid state components, in the professional audio field, there is a demand for the same.
[0232] D. Specific Example 2 (Integrated Circuit-Based) (
[0233] 1. Input Stage
[0234] The input stage sound transducer/capsule 42A can be as described with Specific Example 1 above.
[0235] 2. Buffer Stage
[0236] The buffer 42B and line driver 42C can be implemented with integrated circuits. In this example, the buffer stage 42B includes integrated circuit amplifiers as shown in
[0237] The gain amp/buffer IC amp 42B (parts 1 and 2) provides high gain (e.g. in the range of 25-100 V/mV and is powered by external power (e.g. 3 V to 20 V) via a dedicated amplifier voltage line. External power can be supplied as discussed above and as further discussed regarding external power supply 71 herein).
[0238] One example of a possible IC is Model No. NE5534a from Mouser Electronics of Mansfield, Tex., USA.
[0239] Note that in this example, a rheostat or analogous device (see caption pre amp gain 200) allows some range of manually-controlled variation of gain by varying resistance of the inverting input.
[0240] 3. Line Driver Stage
[0241] The line amp IC 42C provides gain (e.g. in the range of 25-100 V/mV) and is powered by external power (e.g. 3 V to 20 V) via a dedicated amplifier voltage line.
[0242] One example of a possible IC is Model No. NE5534a from Mouser Electronics of Mansfield, Tex., USA.
[0243] Note that in this example, a rheostat (see caption output fader and ref no. 42E) allows some range of manually-controlled variation of gain by infinity to unity gain.
[0244] 4. Output Stage
[0245] An output transformer 42D is used to isolate the circuit from possible downstream damage and match impedances to equipment following, isolate, create or adjust tonality, is part of the overall gain scheme of the unit.
[0246] 5. Housing
[0247] Similarly, the microphone assembly has a single housing of the various mic stages described above. Appropriate cabling and connectors are used.
[0248] E. Specific Example 3 (Solid State-Based) (
[0249] 1. Input Stage
[0250] The input stage sound transducer/capsule 52A can be as described with Specific Example 1 above.
[0251] 2. Buffer Stage
[0252] The buffer 52B and line driver 52C can be implemented with discrete solid state components. In this example, the buffer stage 52B includes discrete solid state components as shown in
[0253] The gain amp stage provides high gain (e.g. in the range of 0 to 30 decibels) and is powered by external power (e.g. +/16 to +/48 V) via a dedicated amplifier voltage line. See discussion elsewhere regarding external power supply for this purpose.
[0254] As shown in
[0257] Note that in this example, a rheostat or analogous control (see caption pre amp gain 200) allows some range of manually-controlled variation of gain.
[0258] 3. Line Driver Stage
[0259] The line amp/output driver stage provides gain (e.g. in the range of 10 dB) and is powered by external power (e.g. 16 to 48 v) via a dedicated amplifier voltage line.
[0260] Examples of possible components are: [0261] Transistor #3 from left Model No. BC560c from Mouser Electronics of Mansfield, Tex., USA. [0262] Transistor #4 from left Model No. 2n1711 from Mouser Electronics of Mansfield, Tex., USA. [0263] Transistor #5 from left Model No. 2n3055 from Mouser Electronics of Mansfield, Tex., USA. [0264] Transistor #6 from left Model No. 2n3055 from Mouser Electronics of Mansfield, Tex., USA.
[0265] Note that in this example, a rheostat (see caption output fader 52E) allows some range of manually-controlled variation of gain.
[0266] 4. Output Stage
[0267] An output transformer 52D is used to match impedances to equipment following, isolate, create or adjust tonality, is part of the overall gain scheme of the unit.
[0268] 5. Housing
[0269] Similarly, the microphone assembly has a single housing of the various mic stages described above. Appropriate cabling and connectors are used.
[0270] F. Generic Example (Mic Body with External Power Supply Unit PSU) (
[0271] 1. Input Stage
[0272] The import sound transducer/capsule 62A can be as described with other examples.
[0273] 2. Buffer Stage
[0274] The circuit of
[0275] G. Specific Example 5 (Kit of Mic, External Power Supply, Cables, Mic Shock Mount, and Carrying Case) (
[0276] By specific reference to
[0277] Microphone 80 can include any of the specific examples of
[0278] As illustrated in
[0279] This allows a microphone system to be portably carried from location to location with all essential components for that particular microphone use. As indicated in
[0280] Cable 88 can be tens of feet long if needed so that it can have high flexibility regarding reaching and connecting to a recording device which could be more remote from stand 210. Thus, power supply 71A is local to mic 80 and requires a relatively short cord 71B. The kit can contain a relatively longer cord 88 for flexibility in reaching different distances to a recording device 19. This also allows flexibility and where mics and musicians want to be.
[0281]
[0282]
[0283] Toggle switch 94 labeled pole has two states. This allows immediate and local control of these types of functions at mic 90.
[0284] The opposite side (
[0285]
[0286] As indicated in
[0287] It can therefore be seen that in embodiment 90 the user has a variety of local control options for mic set up and performance.
[0288] H. External Power Supply Example (
[0289] With specific reference to these figures, one example of an external power supply 71A is shown. As indicated in
[0290]
[0291] Another feature, over and above being an external and portable power supply 71A for mic 90, is auxiliary controls can be included. One example is contour control rotary dial 106 at
[0292]
[0293] It can be appreciated that the basic primary function of providing electrical power to the microphone for operation of the internal components is relatively simple and inexpensive such that a power supply such as this can be provided for each microphone in many if not most situations.
[0294] I. Thermal Management
[0295] As is known in this technical field, the sensitivity of most microphone transducers to sound energy also makes them sensitive to other forms of energy. One is mechanical energy. Thus, in many situations the shock mount such as 211 is utilized to mechanically isolate the microphone, or at least dampen it from physical vibration through whatever it is mounted to.
[0296] Another factor is thermal energy. It has been found that, by integrating the components as suggested in many of the embodiments of the present invention into a single microphone body or housing, thermal management issues may exist. It is also beneficial to attempt as is possible electromagnetic shielding or encasing as many components as possible. This is again to protect them from a variety of forms of energy as well as from environmental factors such as moisture, dust, and the like. However, a housing that encases its components can trap or allow buildup of heat inside. That heat could adversely affect the sensitivity or operation of the transducer or other system components.
[0297] According to aspects of the invention,
[0298] Extra heat created by additional microphone and amplifier circuitry in the body should ideally be controlled. This is to avoid degradation of the transducer over time, and to reduce wear of components inside the microphone body.
[0299] In one example, microphone 100, which could be the same as or similar to any of the examples 20, 30, 40, 50, 60, 70, 80, or 90, could have one or more essentially thermal vents in the body to allow escape of heat.
[0300] One example would be to use on-body controls such as toggle switches 96 and 98 of
[0301]
[0302] One way to build this configuration is shown at
[0303] Slots 97 and 99 can be formed at or near the top of cylinder 114 and allow positioning of the toggle switches 96 and 98 when all the circuitry is assembled. But those slots 97 and 99 can be big enough to both allow access (e.g. via a small screwdriver or other tool) to control the toggle switches but also have open areas around them in communication with the interior 115 of cylinder 114. As shown in
[0304] A subtlety is that capsule mounting plate 117 fits snugly within the microphone body 113 to essentially seal interior 115 from transducer 12A. It also forces hot-air away from capsule 12A and out through the venting as indicated by the arrows.
[0305] As will be understood, this subtlety actually counter-intuitively tries to trap heat. But it uses the arrangement to promote heat movement out of the body 92 and keep it away from the capsule 12A. Under the laws of physics, this passive heat management relies on thermal equilibrium. If heat builds up inside mic body 92 to a higher temperature than surrounding ambient air, equilibrium will be sought, which would tend to transfer heat out and bring the interior temperature towards the outside ambient temperature.
[0306]
[0307]
[0308]
[0309] One optional additional possibility or technique for heat management is to relocate any components that create what might be considered excessive heat inside the microphone body to the external power supply that accompanies the microphone. In one example, this could be large transistors, tubes used for power regulation, or high wattage resistors used for voltage control. See, as nonlimiting examples, reference numerals 128A, B, and C in
[0310] Additionally, similar to venting 119 on mic body 92 mentioned earlier, venting (see arrows in
[0311] J. Gain Control Options
[0312] With reference to
[0313] Local control (at or near the mic) of gain can be beneficial. Gain can be controlled in a number of ways. In the microphone body, the most direct way of controlling gain in the system is by placing a potentiometer or precisely calibrated switch on the body of the microphone. In keeping with system objectives, the signal path is kept as limited as possible, including in many of these implementations being mere inches.
[0314] Gain control of the circuits would usually be accomplished by means of feedback. In the case of tubes from the plate of line driving tube to cathode of the gain and buffer sections as in a preamp design.
[0315] Alternative gain control could be for gain control to function as a counsel fader or preamp output control. In this case, the potentiometer or switch 132 could be placed between gain stages or at the output of the entire system as shown in the circuit diagram of
[0316] Either version of these types of gain control 134 can also be placed on remote power supply as chosen by designer and requirements of the individual system (see
[0317] It should be noted that both types of gain control can be used. This can be done to allow the user flexibility in gain staging the system and creation of textures. For example, the input of the system could be driven to produce harmonically rich textures while the fader is reduced to allow proper output level without distorting the recorder. Conversely, the input could be run at lower levels to create pure transmissions and the output is set to full for maximum head room and fidelity. These are options that no microphone system at present can provide.
[0318] K. Transducer Options
[0319] As shown by diagrammatically at
[0320] L. Supplemental Information About Microphone 80/90 and External Power Supply (Sometimes Power Supply Unit or PSU)
[0321] In the case of a microphone according to microphone 80 or 90 above, one specific exemplary embodiment is discussed in further detail below. It will be seen how it meets one or more features of the present invention.
[0322] The REDD Microphone (commercially available from Chandler Limited, Inc., Shell Rock, Iowa USA; see http://chandlerlimited.com/redd-microphone/ as of 20170919; REDD is a trademark of EMI (UK)) is a large diaphragm tube condenser microphone, combining mic and preamplifier into the microphone body. Featuring the vacuum tube based REDD.47 Mic Amplifier circuit coupled directly to a custom handmade premium platinum membrane capsule, the REDD Microphone can be used with or without an external preamp.
[0323] The proximity of the REDD Microphone's custom capsule to its internal REDD.47 mic preamp circuit, creates the shortest possible path between the two most important elements in the recording chain, delivering a larger than life full-bodied sound, with a silky smooth top-end.
[0324] Features available from the microphone body, include: 9 gain selections, +4 to +33 db in NORM, extended gain and punch in DRIVE, Cardioid/Omni patterns, 10 db Pad, and Phase. Continuous output control and low-contour voicing features are accessible from the high-quality external power supply.
[0325] This exemplary embodiment, e.g. the REDD Microphone, represents a shift in traditional microphone design, bringing together historic circuitry and pre-amplifier sound in a new and unique way.
[0326] The REDD Microphone is a large diaphragm tube condenser microphone, featuring a dedicated internal REDD.47 Mic Amplifier circuit.
[0327] The REDD Microphone system includes: microphone, 7-pin microphone cable, power supply and AC cord, shock mount suspension apparatus, pattern select screwdriver, and custom moulded flight case.
[0328] The REDD Microphone, featuring its on-board REDD.47 pre-amplifier circuit, is contained in a cylindrical metal assembly, directly coupled to a premium custom made, hand-milled, platinum membrane capsule, housed in the chrome head-basket compartment.
[0329] The close proximity of capsule to microphone pre-amp provides the shortest possible distance between microphone capsule and pre-amplifier, allowing the REDD Microphone to drive the line from the source, rather than the end. The all-in-one approach reduces electronic circuitry in the audio path, and allows for high-grade audio transmission from the source.
[0330] The REDD Microphone was designed to plug directly into audio interfaces or tape machines, however, can be used with traditional external pre-amplifiers for more tonal possibilities.
[0331] Technical features are set forth in Table 1 below.
TABLE-US-00001 TABLE 1 REDD MICROPHONE TECHNICAL SPECIFICATIONS Microphone Type Large Diaphragm Condenser, Tube Capsule Platinum membrane, custom handmade, hand-milled Circuit REDD.47 Mic Amplifier, Tube, 200 output impedance Gain Switchable/+4 to +33 db in NORM mode Maximum gain Extended gain in DRIVE mode Patterns Cardioid/Omni PAD 10 db/Switchable Phase 0-180/Switchable Low-Contour Available at PSU Control Output Control Continuous/Available at PSU Power External/PSU included Microphone Cable 7 Pin, 25 Mogami, included Shockmount Included Case Molded flight case/custom cut high-density rigid foam, included
[0332] One example of set up for operation is at Table 2.
TABLE-US-00002 TABLE 2 IMPORTANT QUICK START & POWER CYCLE PROCEDURE 1. Mount the microphone to a suitable microphone stand using the supplied shock mount suspension apparatus. 2. PRIOR TO POWER-UPCONNECTIONS a. Connect the microphone to power supply using the supplied 7-pin microphone cable. b. Connect the user supplied standard 3-pin XLR microphone cable to the audio interface or tape machine. c. Connect the power supply to an AC outlet. 3. POWER-UP a. Once all connections to and from the power supply to the microphone have been made, turn on the power supply, by means of the power switch located at the rear of the PSU. b. If power has been achieved, the microphone's on-board LED, located inside the head-basket, will illuminate red to signify the microphone is active. The LED is also used to help align the capsule to the sound source. c. WARNINGDo not disconnect the 7-Pin microphone cable while AC power is applied to the microphone. If disconnection is to be made, power down the microphone, and allow 5-10 minutes of cool-down time prior to disconnection of the 7-pin microphone cable from the power supply. NOTE3-pin XLR audio output connection may be patched or unpatched as necessary, without powering down. 4. WARM-UP TIME a. Prior to sound incident or usage, allow the microphone's tubes to warm-up for a minimum of 10 minutes. 5. POWER DOWN a. Prior to disconnecting the 7-pin cable, power down the PSU, and allow 5-10 minutes for the microphone's internal tubes to cool down and the capsule adequate time to discharge. NOTEIt is recommended to power down the REDD Microphone when not in use.
[0333] Specifics about the on-board controls are as follows:
ON-BOARD MICROPHONE CONTROLS
[0334] A. PRE AMPLIFIER
[0335] The dedicated on-board REDD.47 Mic Amplifier (pre-amplifier) circuit provides the ability to use the REDD Microphone with or without the need for an external pre-amp. The preamplifier and most of its available features are adjustable directly from the microphone body.
[0336] 1. GAIN
[0337] NOTE: Adjust this switch for the desired amount of input gain, stepped, from +4 to +33 db
[0338] The on-board microphone pre-amplifier gain setting is adjustable at the rear of the microphone. There's nine gain settings to choose from, including: +4,8,12,16,24,27,30,33 db. The resultant effective gain is also dependent upon the NORM vs DRIVE mode setting; selection of either NORM or DRIVE mode is available via toggle switch from the front of the microphone body, and have a tonal effect on the microphone signal.
[0339] 2. TYPE
[0340] NOTE: Use this switch to select between NORM and DRIVE modes. Drive boosts the microphone's internal REDD.47 preamp for additional character and punch.
[0341] a. NORM
[0342] When the toggle switch is set to NORM, the REDD Microphone pre-amplifier is considered in its normal operational condition. The sound characteristic in this state, is more organic or natural, or laid-back in comparison to DRIVE.
[0343] b. DRIVE
[0344] The DRIVE setting has an overall effect over the adjustable gain range, both in terms of structure and more importantly, harmonic content. It is similar to the FINE GAIN on the REDD.47 Mic Amplifier rack-mount counterpart, however, set fully on and non-variable.
[0345] When set to the DRIVE position, the tonal effect on the microphone signal is identifiable, characterized as being more immediate, punchy and present. The resultant tonal change is also interactive and dependent upon the gain setting.
[0346] Depending upon the sound incident level and gain setting, DRIVE mode, if driven hard enough, can impart wonderful harmonic coloration and tube saturation with a little characteristic hair on a signal.
[0347] 3. POLE
[0348] In cases where phase continuity relative to other microphones in the environment is required, an 180 polarity reversal of the output signal is achieved by use of the POLE or phase reverse toggle switch available from the microphone body.
[0349] When the toggle is set outward, to the circular or O designation, phase is in its natural position at 0. Conversely, when the switch is positioned to the left at the designation, phase is reversed 180.
[0350] 4. POLAR PATTERNS
[0351] NOTE: Use this toggle switch to select between Cardioid or Omni Polar patterns. The directional characteristic of the REDD Microphone is selectable. Two polar pattern options are provided, Cardioid or Omni-directional, either is available via toggle switch from the microphone body, using the supplied pattern select screwdriver.
[0352] a. CARDIOID
[0353] This unidirectional polar pattern discriminates against source arriving at the rear of the capsule, and to a lesser degree at the sides, in preference for sound incident at the front of the microphone.
[0354] Proximity effect is a natural occurrence of the Cardioid polar pattern, where low-end is emphasized when the sound source is closer to the microphone.
[0355] TIPIf in Cardioid, the microphone is required to be placed in close proximity to a source, such as acoustic guitar, where capture of low frequency data is less desired, or in small environments where natural build-up can occur, use the LOW-CONTOUR feature as an alternate microphone voicing; See LOW-CONTOUR control section. If Cardioid is not required, and LOW-CONTOUR is unnecessary, the Omni pattern can be used to diminish proximity effect.
[0356] TIPUse the Cardioid pattern in scenarios where minimal pickup at the rear of the microphone is needed.
[0357] b. OMNI
[0358] The omni-directional polar pattern is spherical, picking-up from all sides of the capsule, e.g. the pattern is indiscriminate to the direction of sound incident.
[0359] Proximity effect is not a feature of the Omni pattern, and as a result, an apparent drop in lows (and gain,) is a normal byproduct of this setting.
[0360] TIPUse Omni where a sense of space is apropos, for example, strings, acoustic guitars, pianos or other material, or a more natural distribution of low-end is preferable.
[0361] 5. PAD
[0362] NOTE:Use this switch to engage (or disable) the 10 db PAD.
[0363] Facility to decrease sensitivity of the microphone by -10 db exists, and is made available from the microphone body via toggle of the PAD switch to the downward position, using the supplied pattern select screwdriver.
[0364] TIPUse the PAD feature in scenarios where the sound incidence is overloading the capsule.
[0365] Specific regarding the power supply and its controls is as follows.
POWER SUPPLY & AUXILIARY CONTROLS
[0366] The power supply (PSU,) supplied with the REDD Microphone kit is wired localized for regional AC, either 110V or 220V (115/230V, depending upon country of purchase. A REDD Microphone kit purchased in a region where AC is 110V (115V) standard cannot be used in 220V (230V,) unless it is modified for the correct operating voltage or an external power converter is used. NOTE: Some external power converters.
[0367] A. PSU REAR PANEL
[0368] 1. AC POWER
[0369] At the rear panel of the PSU, exists a standard male IEC connector for connection to AC power, using the supplied IEC cable.
[0370] Also at the rear PSU panel is bayonet style fuse compartment. For fuse replacement procedure and value, please reference the maintenance section of the manual.
[0371] 2. POWER SWITCH
[0372] The master power switch is located at the bottom left of the PSU rear panel and labeled ON/OFF. Once all connections, to and from the microphone to the PSU have been made, flip the power switch to supply mains power to the microphone. NOTE: The microphone head basket will illuminate, signifying power is on.
[0373] B. PSU FRONT PANEL
[0374] 1. MIC INPUT
[0375] The top receptacle is a 7-pin female jack. Plug the supplied 25 (762 cm) 7-pin microphone cable here, and attach the female end of the cable to the microphone base connector.
[0376] 2. LINE OUTPUT
[0377] The bottom receptacle is a standard 3-pin male XLR jack. This output jack supplies analog line level signal to your audio interface converter, tape machine, or other external audio processor; the source (output) impedance is 200 ohms.
[0378] 3. OUTPUT CONTROL
[0379] The OUTPUT control is continuous, acting as a fader would on a console, and is used to reduce the overall output of the REDD Microphone; this control is functionally the same as the REDD.47 Mic Amplifier rack-mount.
[0380] In most applications, attenuating the output of the microphone signal maybe unnecessary and should be left fully clockwise at unity or 0. However, if reduction of the overall output signal is required, simply rotate the OUTPUT control counterclockwise until the level desired level is achieved.
[0381] TIPOn drums room application, if a driven sound with tube saturation is the goal, turn up the gain, engage DRIVE and turn down the OUTPUT to not clip your converter's input.
[0382] The OUTPUT control is operational regardless of the PULL FOR LOW CONTOUR feature being actuated or not.
[0383] a. LOW-CONTOUR
[0384] The LOW-CONTOUR function is an alternate voicing of the REDD Microphone, it features a tighter sound with top-emphasis and is an excellent choice for many sources.
[0385] LOW-CONTOUR is available from the power supply (PSU,) to actuate the LOW-CONTOUR voicing, simply pull the OUTPUT control potentiometer outward; the OUTPUT control is still fully operational.
[0386] TIPIn recording scenarios and environments, where a more top-emphasized sound and a tailored low-end may be desired, the LOW-CONTOUR voicing is well suited for this purpose.
[0387] One example of form factor and features are set forth in Table 3.
TABLE-US-00003 TABLE 3 ITEM DESCRIPTION DIMENSIONS WEIGHT Microphone Tube, Large 10.97(L) 1.11 lb/ Diaphragm Condenser 2.46(W) in 0.504 kg (278.64 62.48 mm) Capsule Platinum membrane, X X custom handmade, hand-milled Circuit REDD.47 Mic X X Amplifier, Tube 2 Gain Switchable/to +33 db X X in NORM mode Maximum Extended gain in X X gain DRIVE mode Patterns Cardioid/Omni X X PAD 10 db/Switchable X X Phase 0-180/Switchable X X External PSU, AC set 11.4(L) 5.02 lb/ Power supply internally for region, 4.04(W) 2.28 kg included 4.81(H) in (289.56 102.62 122.17 Low-contour Preset, switchable X X control Output Continuous, 200 X X control out-put impedance Fuse AMP, 250 V X X SLO-BLO Accessories Microphone 7 Pin, Mogami 25 X cable (Neglex 3172,) (7620 mm) included Ac cable Type IEC, included 6 X (1828.8 mm) Shockmount Included X X Pattern select included X X screw-driver Case Molded flight case, 21.85(L) 20 lb/ included 8.31(W) 9.07 kg, 16.85(H) in loaded (555 211 428 mm)
[0388] M. Other Options
[0389] As previously mentioned, variations obvious to those skilled in the art will be included with the invention. Some of those have been mentioned above. Further examples are set forth below.
[0390] 1. Housing
[0391] A variety of form factors can be used. As a general rule, it can be beneficial that the housing be at least similar in form factor to existing professional audio mics both for portable, hand-held ability, and familiarity with musicians, but also to interface with existing mic stands or holders.
[0392] The form factor can be selected by the designer. The factors a designer typically would consider would include: [0393] a. head or grille of microphone, properties of can affect the overall sound of the mic; [0394] b. body shape or shell; [0395] c. base; [0396] d. connector for power and audio.
[0397] 2. Capsule
[0398] A few non-limiting examples are:
[0399] a. dynamic (does not require phantom voltage;
[0400] b. condenser (can require phantom voltage);
[0401] c. electret (requires voltage);
[0402] d. ribbon (does not require voltage).
[0403] 3. Buffer/Line Driver/Output Stages
[0404] The description above gives examples of each. Variations obvious to those skilled in the art will be included.
[0405] 4. Faders
[0406] Use of either the pre amp fader or the output fader are optional.
[0407] 5. Transformers
[0408] The specific make up of any of the transformers can vary according to the designer's needs or desires. Those skilled in the art would understand the factors which include impedances, inductances, resistance, transformer lamination construction and variation, winding styles and variations.
[0409] As will be appreciated by those skilled in the art, the types and values for some of the components in any of the three specific exemplary embodiments can vary according to desire or need. For at least some implementations of any of the tube, IC, or discrete solid state versions, the designer could design and create customized components and/or sub-circuits. For example, transformers, transducers, transistor application, and tube application can be customized or created to meet desired operating characteristics according to the design rules discussed above.
[0410] As can be appreciated from the foregoing, aspects of the invention can be embodied differently for different needs and desires. The designer utilizes the same fundamental idea of essentially integrating a preamp into the microphone body with appropriate other components to allow direct plug in to a recording counsel via the use of in addition, an external power supply to the mic. (See, e.g.,
[0411] As further indicated by the examples, whether called stages or components, the reader will understand that there is flexibility in implementing the general concept regardless of how those are denominated. In other words, in its basic form, a transducer with sound is needed and at least the preamp type circuitry or components with some sort of output stage. External power is also utilized to the mic.
[0412] Also, as shown, connection cords can vary.