AUdIoCoUrSeS
Joined: 31 Oct 2002
Posts: 2014
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| Week 6 - Digital Consoles |
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Focussing entirely on digital mixing consoles and their operation this week.
This is hardware based rather than software so you are going to have to research lots of different models.
When descibing these do also think about how the function works in terms of the binary.
Describe and explain digital mixing consoles and their operation:
• Comparison with analogue consoles
• Analogue components of digital mixing consoles
• Microphone preamplifiers and line-level inputs
• Talkback and communications
• Interface with analogue and other digital equipment and systems
• Features and functions
• Assignability in digital consoles
• Operational procedures
• Automation and recall
• Plug-ins
_________________
It's all in the ears. - Learn the concepts not the software.
Audio Courses is a way into the music business for you
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Mon Oct 03, 2005 4:12 am |
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Polarman
Joined: 24 Jun 2005
Posts: 55
Location: Barbados |
| Digital Mixing Consoles |
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I want a digital mixer!!! 
Comparison with analogue consoles
In a digital mixer all incoming analogue signals are converted to digital. In that way all functions on the signals will be done in the digital domain. Digital inputs and outputs make it possible to connect recording devices, processors and effects digitally with no need to convert to analogue. This is a big advantage since the digital signal is more robust then a analogue signal; no crosstalk, unaffected by lead capacitance, electromagnetic fields, distortion and noise. Processing and effects can also be carried out in the digital domain without to convert to analogue. The digital mixer is also more ergonomically different from analog mixers. The digital mixers are normally smaller because there is no need to have as many faders as you have channels, any fader can be assigned to any channel. Digital mixers are normally fully automated and have a total recall which means that you can easily work on many projects at the same time.
Since one knob controls the EQ for all the channels, digital consoles have fewer controls than analog consoles. One knob or switch can have several functions. This makes digital consoles harder to operate than analog ones because, with a digital console, you can’t just reach for an EQ knob for a particular channel. You have to do several button presses to set the EQ parameters.
Digital consoles have built-in effects and automated mixing. You can set up different mixes, store each mix in the mixer’s memory, and recall each mix with the press of a button. When you recall a mix, some mixers make the faders move into the positions you set up. Other mixers do not move the faders when you recall a mix. You have to set them manually by looking at a display, which is a disadvantage.
In an analog mixer, all of the connections, inputs and outputs, are "hardwired". Once the design is finished, the mixer can never change. In a digital mixer, once the audio is inside the mixer, there is virtually total freedom to move it around, add effects, and configure its paths anyway you need to for your application. For example, any input can go to any or all channels. And the various paths within a digital mixer can be routed to many different destinations as well as different physical outputs.
Analogue components of digital mixing consoles
The analogue components of a digital mixing console are the microphone preamplifiers and the line inputs/outputs. They are used to amplify an incoming analogue signal and are then fed into the A/D converter to convert the signal to digital. The quality of these depends on the mixer, as a more expensive digital mixer will probably include better microphone preamps and A/D and D/A converters than a less expensive mixer.
Microphone preamplifiers and line-level inputs
See above
Talkback and communications
Some mixers contain a built-in microphone that allows the engineer to talk to musicians in a studio or onstage, either through their headphones or a speaker. It will also allow you to numer or mark each recording attempt by assigning it a take number that you’ll announce into the mic as recording begins. A talkback system will include the mic, a button for activating and de-activating the mic, and a volume control for the mic. You can also use one of the channels to route the signal to the musicians monitor system.
Interface with analogue and other digital equipment and systems
The digital mixers are getting easier to integrate with outboard equipment and Digital Audio Workstations. In this way you can easy get a fully integrated system. To be able to use analog equipment without any digital in/outputs you have to convert the signal to the analogue domain and convert it again to the digital domain but keeping your audio in the digital domain avoids the audio losses from numerous A/D and D/A conversions.
Most outboard gear nowadays has digital in/out which makes it possible to add processing and effects without conversation. Digital mixer has both analogue and digital in/outputs. Normally a digital mixer uses ADAT optical interface, TDIF, S/PDIF and AES/EBU to connect digitally. To make analogue connections ¼ Inch Phone, TRS Phone, XLR Connectors and some mixers let you use Y -cables to send to and from an external device. Some digital mixers are specially designed to be fully integrated to a specific software like Digidesigns ICON with Protools or Yamaha with Nuendo.
Features and functions
A digital mixer usually have 24, 48, 72 or 96 channels and can operate in 44.1 KHz, 48 KHz, 88.2 KHz, 96 KHz and 192 KHz. They work internally with 32 up to 56 bits internally. Most features are totally automated.
Because the audio in a digital console has entered the digital domain, it is easy to add very high quality, on-board digital effects processing. Since this processing is an integral part of the mixer, you avoid the audio losses of cabling, external patching and audio conversions inherent in an analog console.
The internal processing power in a digital mixer can also be reconfigured. For example, you could have a Real Time Analyzer for live concert work or when you are first tweaking the sound in your studio. You could configure your console so you have compressors on 20 or 30 inputs or configure your effects to be a Mastering Tool Kit with multi-band compressors and expanders as you mix digitally to CD or DAT.
To help speed up working on a project, a digital mixer may have libraries of different EQ settings or dynamics presets. These libraries are available to use in any project, so you can store your favorite EQ for recording a bass or a drums. You can also use the presets to help you get started processing your audio.
Scenes are pictures of every parameter of your digital mixer: from the levels to the EQ to the FX settings to the bus routings; everything. Scenes let you recall a mix just as you left it, so you can get right to work on it again. Scenes allow you to bring back the exact settings you used when you recorded a vocal, so you can overdub with the same EQ and levels. Scenes let you store your current mix idea, work on another great idea you just had, then compare the two. They can also let you instantly reconfigure your mixer for live concerts if you need different levels, FX or mic settings between songs, or from one band to another. Scenes can be used whether you are mixing or tracking or overdubbing or doing live concerts.
Assignability in digital consoles
In an analog console, all of the channels and busses have fixed hardwired paths. For this reason, some analog consoles are designed for mixing and recording purposes and others for live mixing. Most of the design difference is based on the busses and how they will be used. Some powerful digital mixers have busses that are much more flexible than analog busses. These flexible busses combine all of the features of every type of analog bus. They have send levels and can be sent PRE or POST fader (and even from more locations along the channel strip). The outputs of a bus can also be sent to different destinations as well. A digital console with a very flexible bus structure can be configured by the user for just about any mixer application imaginable. They can be used for sending audio to internal or external effects, to either analog or digital recorders, to headphone amplifiers, to monitors or studio speakers.
Operational procedures
I am not 100% sure what this question really means. Do you want standard procedures for recording, mixing and mastering outlined?
- Connect all instruments to the line level inputs like electric guitar, samplers, synths etc.
- Connect the mics to the microphones inputs.
- Connect the analogue outboard gear to analogue send and return and your digital outboard to digital outputs and inputs. Set up a send group for the foldback.
- Connect the mixer to your multitrack recorder.
Automation and recall
Digital consoles can to store and then recall all of the settings of a mix, even including the effects. This allows you to work with a project, store its settings and later come back to the mix exactly as you left it. A mixer with memory has lots of other advantages. For example, you could recall a vocal’s EQ and level for a new take or to punch in over an old version with matching audio quality. The speed of recall also allows you to try one mixing approach, store it, try a completely different idea, and then compare the two.
There are two basic types of automation: snapshot and dynamic.
Snapshots are complete pictures of your mixer: all of the effects settings, levels, etc. Some digital mixers let you customize which mixer parameters are stored in your snapshots. You place a snapshot where you need an effects patch change on your guitar part, an instant volume change for verse to chorus vocal or anywhere you want an immediate mixer adjustment the change happens automatically. Snapshots are also used for internal FX to have different effects at different times.
Dynamic automation is used for gradual changes of parameters such as a fade out. For example, you could use dynamic automation to recall every little level move you make to your vocal track. Once you have it right, you can then move on and work on the drums, knowing that the vocal track is now perfect. Some digital consoles have moving faders that help you see exactly what is happening during your mix. The memory for this automation in your digital mixer can be on board or it can be transmitted via MIDI. If it is MIDI based automation, then you would use a sequencer to play back the automation data during your mix.
Plug-ins
Digital mixer comes often with internal effects and processors. Often it’s also possible to upgrade these. In addition to this some mixer has the ability to use third party plug-ins, like audio metering tools, de-essers, distortion and speaker cabinets modelling, delay, filter effects, pitch correction etc.
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http://www.stagetec.com/stagetec/cinetra-en-lores.pdf
http://psbg.emusician.com/ar/emusic_mixed_signals/
http://entertainmentdesignmag.com/mag/show_business_digital_consoles_theatre/
http://mixonline.com/nab2005/NAB-MIXING-CONSOLES/
http://www.muzeekworld.com/recordingproducts-digitalmixers.htm
http://www.bossus.com/index.asp?pg=4&tmp=6
http://www.svconline.com/mag/avinstall_digital_consoles/
http://www.tape.com/Bartlett_Articles/mixers.html
http://www.svconline.com/mag/avinstall_digital_consoles/
http://www.mackie.com/products/d8b_v5/plugin_info.html
Watkinson, J. (2001). The Art of Digital Audio, 3rd ed. Oxford, Focal Press
Rumsey, F. & McCormick, T. (2004). Sound and Recording: An Introduction, 4th ed. Oxford, Focal Press
Pohlmann, Ken C. (2005). Principles of digital audio, 5th ed. New York, McGraw Hill |
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Fri Oct 07, 2005 8:42 pm |
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rachelh
Joined: 16 Jan 2005
Posts: 35
Location: Trinidad WI |
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Week 6 - Digital Consoles
Describe and explain digital mixing consoles and their operation:
• Comparison with analogue consoles
The fundamental function of an audio production console is to give the user full control over volume, tone, blending of signals and spatial positioning for all or any of the signals that are applied to its inputs from microphones, electronic instruments, effects devices, recording systems and other audio devices.
Analogue consoles have the ability to transform an electric input signal to its corresponding magnetic energy that can be stored onto tape in the form if magnetic remnants. On playback this energy is reconverted to a corresponding electrical signal that can be amplified and processed. A more flexible production environment is in demand due to the need for increasingly sophisticated production values. However developing analogue consoles that are more sophisticated to meet today’s demands leads to ergonomic obstacles. When one tries to interface digital signal processing equipment and digital storage media with analogue mixing circuitry negates some of the advantage of digital as a recording medium. The combination of higher fidelity standards, greater versatility and easier operation and enhanced interfacing has lead designers to the digital mixing console as a more cost effective solution. The combination of low cost electronics as well as specially designed DSP circuits and its relatively large production runs have lead to the digital medium to be more cost effective to buyers. However, the sonic characteristics of analogue audio have kept it around to the point that analogue sound is sought after by many recording enthusiasts and studios.
In both digital and analogue consoles the gain coefficient will originate from the hand operated faders. Analogue consoles that have an automated mixdown feature have faders that produce varying voltage, which is then converted into a digital code or gain coefficient in an Analogue to Digital Converter [ADC] and is recorded alongside the audio tracks. On replay the coefficients are reconverted to analogue voltage, which control the VCA’s, which occur in series with the analogue audio channels. Digital consoles have the same structure as well as coefficient capturing process but in stead of converting the signal back to an analogue form on playback it remains in the digital realm and control the digital multipliers in the digital audio channels directly.
[1][2][3]
ANALOGUE CONSOLE FEATURES:
1. Channel input – serves to optimise the signal gain levels at the input of an input/output [i/o] module before being further processed or routed. Either mic or line inputs can be selected whose gain trim can be altered.
2. Auxiliary send section – are used to route mix signals from an input strip to the various effect sends and possibly monitor/ headphone cues of a console. These sends are use to recreate a sub-mix of any or all of the various console inputs in a mono or stereo send which then can be routed to any destination. Usually up to eight aux sends can be found on an input strip.
3. Equalisation section- the EQ section of an analogue recording console like the auxiliary send section derives its feed from the same source that is, the channel input section. EQ is used to correct any discrepancies in the audio signal. EQ sections usually include up to four continuously variable overlapping frequency control bands each of which has a varying bandwidth [Q] and a boost and cut control.
4. Insert Point – at this point a direct send/ return or insert access point can be used to send the line level audio signal out to an external processing device or recorder. One vital point to note is that plugging in a dynamics, EQ or effects processor will only affect the signal that is passing through the selected I/O channel
5. Dynamics Section – this section is located in each of the I/O modules. It allows the signal to be more easily dynamically processed without the use of outboard devices. Here is where compressors, limiters, expanders and gates are located.
6. Monitor section – is a means of creating a separate monitor mix in the control room as a means of hearing a musically balanced version of the project. A separate monitor section is usually designed in to the console to provide control over each inputs level, pan and effects and then route this mix to the control room’s mono, stereo or surround sound speakers.
7. In Line Monitoring – newer analogue consoles provide a I/O small fader section which can be used to directly fee the recorded signal that is being fed to either the multitrack recorder or the monitor mixer
8. Separate Monitor Section - analogue consoles of older and usually English design have an entirely separate monitor section, which is generally located on the right hand side of the console. This separate monitor section allows for level, pan, effects and foldback to be monitored with the inputs for this section driven by the console’s multitrack output and tape return busses.
9. Direct Insertion Monitoring – uses the direct sends / returns of each input strip into the insert of the recorder directly into the input strip’s signal path. By doing this, the direct send of each associated tape track before or after the EQ section can be routed to the associated track input on a multitrack recorder.
10. Channel Assignment section- the track assignment matrix usually precedes the main to tape fader and distributes the signal to any or all of the tracks in the multitrack recorder. Pressing any or all of the assignment buttons will route the input strip’s main signal to the corresponding track output buses.
11. Output Fader – each output strip is equipped with a main output fader, which determines the level of the signal as well as pan pot [left/right and surround] positioning. This section also includes a solo/ mute function
12. Output Bus – a bus is a single electrical conduit that runs the horizontal length of a console or mixer, signals can be injected into the bus line and be routed off the bus to one or more output destinations
13. Master Output / Group Faders – the master output fader allows the overall levels of an output bus to be trimmed. The master output fader or rotary pot serves as a convenient point for controlling group output levels that are being sent to tape, a device or other recording media.
14. Monitor Level section – a central monitor section that controls the levels for various monitoring functions, this section makes it easy to switch between various monitor speakers and can also provide the option to switch between the various sources and recording devices that are found in the studio
15. Patch Bay – a panel that contains accessible jacks that correspond to the various inputs and outputs of every access point within the recording console
16. Metering section – each input, line output and other level point is often measured by a meter that displays the signal level’s strength, meter and indicator types differ from system to system
DIGITAL CONSOLE FEATURES:
1. Digital consoles have the same features as their analogue counterparts only that these devices use large-scale integrated circuits and central processors to convert, process, route and interface to external audio and computer related devices to convert and store audio in the digital domain. Although digital systems interface with the signal path in ways that differ from analogue consoles, the digital signal path is conceptually the same as the analogue signal path.
2. Digital consoles have centralised control panels that is used to control and vary the particular channel setting parameters such as auxiliary send, dynamics, EQ or track assignment settings which contrasts to the way these settings are changed as stated in the analogue console features above. This panel can be multipurpose in its operation allowing itself to be reconfigured via the use of software [soft] buttons, pan and level controls.
3. Console features can be controlled by physically placing a readout display at each central point on the input strip at locations that are similar to the way it would be done on an analogue console
4. In contrast to analogue consoles, digital input strips can gain access to the central control panel if channel select is pressed on the desired channel
Digital console designs are available in two forms:
1. Fully digital
2. Digitally controlled analogue console- the signal path is distributed and processed in an analogue form whilst the control over the console parameters is carried out in the digital domain
[3]
• Analogue components of digital mixing consoles
Digital consoles and digitally controlled analogue consoles have the same features as their analogue counterparts only that these devices use large-scale integrated circuits and central processors to convert, process, route and interface to external audio and computer related devices to convert and store audio in the digital domain. Although digital systems interface with the signal path in ways that differ from analogue consoles, the digital signal path is conceptually the same as the analogue signal path. From a functional standpoint the basic flow of a digital console is the same as an analogue console – the input will firstly need to be boosted in level by a mic/ line preamp and then will be converted it digital and passed through functional processing and routing blocks until the main channel output or assigned output grouping is reached. [3]
• Microphone preamplifiers and line-level inputs
The nominal output of a microphone is usually low and depends on the type of microphone and usually is in the order of 1 mV and is known as mic level whilst line level has a nominal value that is closer to 1 V. Line level signals are normally quoted at being referenced to a level of .775 volts. Mic level signals are about 60 dB less than line level and require amplification to bring the signals up to line level. Amplifiers are usually built into the channels and gain control is provided to offer amplification of between 30 and 80 decibels. It is good to note that there is no difference between mic preamps for analogue and digital consoles; the difference is between small and large format consoles where large format consoles have better quality preamplifiers.
[3][4][5]
• Talkback and communications
Talkback is the system in the recording studio whereby it allows for communication between the musicians and the producer/ engineer when they are not working in the same room. It is achieved usually using a small microphone, which is built into the recording console and can be routed to a number of destinations. The destinations of which we speak would be usually aux sends, multitrack buses, mix bus, studio loudspeakers and foldback.
[4]
• Interface with analogue and other digital equipment and systems
When one tries to interface digital signal processing equipment and digital storage media with analogue mixing circuitry negates some of the advantage of digital as a recording medium. The combination of higher fidelity standards, greater versatility and easier operation and enhanced interfacing has lead designers to the digital mixing console as a more cost effective solution. In the dynamics section of a mixer, signals can be processed without the use of outboard devices; compressors, limiters, expanders and noise gates are located here. At the insert point of a digital mixer a direct send/ return or insert access point can be sued to send the line level audio signal out to an external processing device or recorder. One vital point to note is that plugging in a dynamics, EQ or effects processor will only affect the signal that is passing through the selected I/O channel. The output of a console also has an insert point making it easy for this signal to be processed further.
[2][3]
• Features and functions
1. Digital consoles have the same features as their analogue counterparts only that these devices use large-scale integrated circuits and central processors to convert, process, route and interface to external audio and computer related devices to convert and store audio in the digital domain. Although digital systems interface with the signal path in ways that differ from analogue consoles, the digital signal path is conceptually the same as the analogue signal path.
2. Digital consoles have centralised control panels that is used to control and vary the particular channel setting parameters such as auxiliary send, dynamics, EQ or track assignment settings which contrasts to the way these settings are changed as stated in the analogue console features above. This panel can be multipurpose in its operation allowing itself to be reconfigured via the use of software [soft] buttons, pan and level controls.
3. Console features can be controlled by physically placing a readout display at each central point on the input strip at locations that are similar to the way it would be done on an analogue console
4. In contrast to analogue consoles, digital input strips can gain access to the central control panel if channel select is pressed on the desired channel
[3]
• Assignability in digital consoles
Channel Assignment section- the track assignment matrix usually precedes the main to tape fader and distributes the signal to any or all of the tracks in the multitrack recorder. Pressing any or all of the assignment buttons will route the input strip’s main signal to the corresponding track output buses.
[3]
• Operational procedures
The recording console is the centre of all studio operations it is the central entity to which all signals pass through and can be routed to other devices, the console itself may have control over outboard devices it also has control over automation as well as tape machines.
Operation wise an audio signal is inserted into a channel input, then, it can be altered using effects devices, sent to various monitors or effects devices -altered sonically, outputted and finally mixed down to its final form.
• Automation and recall
Automation can be described as the storage of dynamic fader positions against time. Mixing desk automation is designed to help the engineer simplify automation when the number of simultaneously used faders is too many to handle by just one person. This is done by creating sub-areas of the mix at each pass; this gradually builds up the finished product [under computer control] making it easy for the engineer to edit. In practice, an automated system can range from able to only sense only the position of a volume fader and level-related switching functions [this is often called snapshot automation due to the representation of the mixer or console setting at only one point in time] to being a fully automated system that can store and recall all the dynamic functions of a production console. Console automation allows for faders to be easily arranged into one or more groups. Fader grouping is done via the use of a single control voltage or digital value, which is used to control the relative balance of several, grouped channels and/ or tracks. These sub areas are then edited during the mix down process and executed under computer control during a final mix pass. Since digital consoles already speak the language for automation that is, digital, it is much easier and cost effective to code and decode gain, effects, routing and other automation functions.
Write/ update/ read refers to the modes of automation. During the write mode, the mix moves are recorded into memory in real-time. Update mode allows for the already stored data can be updated and modified with only changes being recorded [update/offset mode]. Read mode refers to playback of the mixed information directly from the system’s automation computer.
Recall in automation describes the process by which the operator/ engineer is told the correct placement of controls, leaving it up to the user to reset the controls if desired. This term namely Total Recall was coined by SSL for its system, recall helps in saving time as the user is saved from writing down the positions of every knob and button allowing for the console to be easily reset during sessions. It is to be observed that Total Recall differs from True Total Reset as the latter allows for an interface to be positioned between the automation system and every control located on the console.
A section of automated data may be re-recorded via the use of the scans, which observe the various controls of a mixing surface during the course of a mix. In Write mode, the automation system will detect the associated changes and convert them in a series of corresponding digital words that can be stored directly into the computers automation memory. After the tracks are written, update mode can be used to go back at a later time to alter mix settings originally written to memory, once a control is altered or if automation is re-recorded or reversed in the input strips the updated settings can be changed by adding or subtracting from the track data rather than completely re-writing it. In this way complex moves can be obtained and remain intact while other changes are implemented.
The update mode allows automated punch ins to be blended smoothly with existing data and can be used to go back at a later time to alter mix settings originally written to memory, once a control is altered or if automation is re-recorded or reversed in the input strips the updated settings can be changed by adding or subtracting from the track data rather than completely re-writing it. In this way complex moves can be obtained and remain intact while other changes are implemented. The data is blended smoothly due to the process of level matching which ensures that the punched in data levels correspond to the pre-existing ones, allowing for seamless transition. When using a moving fader this is automatic, for VCA this is done manually by observing the nulling indicator.
The concept of total automation resounds around the principles of an assignable mixing console. This assignable mixing console allows for ease in the implementation of storing switch closures and settings into memory [via the use of a microprocessor] therefore allowing for reiteration to be quickly done. Because a digital console inherently speaks the ‘digital language’ total recall automation is more effective than using an analogue console. With digital consoles it is much easier and cost effective to code and decode gain, effects, routing and other automation functions thus, making assigning a digital console for total automation an easy task. Analogue consoles call for converting the positions and moves of the various dynamic controls on a mixing surface [such as volume, Equalisation and Sends] into a DC voltage that can then be converted into digital data which is a longer process than that employed by a digital console [3][4][7]
• Plug-ins
Plug-ins, recording equipment and software in the digital realm emulate their analogue counterparts because it is a sound that users are accustomed to. External plug-ins can be inserted at the Insert Point of the console where a direct send/ return or insert access point can be used to send the line level audio signal out to an external processing device [such as noise gates, filters, meters, de–essers etc] or recorder. One vital point to note is that plugging in a dynamics, EQ or effects processor will only affect the signal that is passing through the selected I/O channel
[3] [7]
REFERENCE:
1. Principles of Digital Audio 5th edition – Ken C. Pohlman
2. The Art Of Digital Audio 3rd edition– John Watkinson
3. Modern Recording Techniques 5th edition – David Miles Huber, Robert E. Runstein
4. Sound and Recording an Introduction 4th edition – Francis Rumsey, Tim McCormick
5. http://recordinginstitute.com/y2kplus/ARP/index.html
6. http://www.wwsrs.co.uk/format.htm
7. www.sweetwater.com |
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Sun Oct 09, 2005 9:32 am |
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AUdIoCoUrSeS
Joined: 31 Oct 2002
Posts: 2014
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| Good Work |
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Yes Polarman you may well enjoy a digital desk!
Regarding operational procedures you might want to mention how analogue and digital can differ, you know all that sub-menu stuff for setting retrieval etc.
Good work!!!
In fact we could use this as an audiocourses.com article!
_________________
It's all in the ears. - Learn the concepts not the software.
Audio Courses is a way into the music business for you
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Sun Oct 30, 2005 2:36 pm |
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Polarman
Joined: 24 Jun 2005
Posts: 55
Location: Barbados |
Hi Chris!
I will check the operational procedures more closely, absolutely.
Yes it would be great to contribute to audiocourses.com through an article or by any other means.
Whats the next step?
Kris |
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Mon Oct 31, 2005 11:30 am |
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