What are the system requirements for PRE?

What are the system requirements for PRE? When used as a stand-alone microphone preamplifier, PRE is ready to use. For remote control within Pro Tools, PRE requires: • Pro Tools TDM hardware and software: • Pro Tools HD-series system, running Pro Tools TDM 6.0 or later on Macintosh OS X • Pro Tools HD-series system, running Pro Tools TDM 5.3.3 or later on Windows • Pro Tools|HD-series, Pro Tools|24 MIX-series, or Pro Tools|24 system, running Pro Tools TDM 5.3.1 or later on Macintosh OS 9.x • Digidesign-qualified Macintosh or Windows computer • 17" or larger color monitor; 1024x768 resolution • Digidesign-qualified MIDI interface Mic Preamps in Pro Tools can optionally be remote- controlled by Digidesign control surfaces (such as Control|24 and ProControl). [Page View]

What is included with my PRE?

What is included with my PRE? PRE AC Power cable PRE guide [Page View]

Where can I find a Pinout diagram for the DB-25 connector on the PRE?

Where can I find a Pinout diagram for the DB-25 connector on the PRE? Page 41 of the PRE guide (Appendix B). This document can be found online at: http://www.digidesign.com/support/docs/PRE_Guide.pdf [Page View]

Specifications for the Digidesign PRE.

Specifications for the Digidesign PRE. PRE Specifications: Gain Range 0 dB to +69 dB, in approximately 3 dB steps. With Pad enabled, –18 to +51 dB. Input Impedance (Input Z): 1.5k ohm (low impedance); 15k ohm (mid impedance); 1.5M ohm (high impedance) Frequency Response: ±0.1 dB; 20 Hz to 20 kHz, @ +48 dB gain Total Harmonic Distortion + Noise <0.0005% @ 1 kHz, 0 dB gain @ 20 dB signal; <0.001% (20 Hz to 20 kHz), 0 dB gain @ 0 dB signal Equivalent Input Noise –128 dB @ 66 dB gain (20 Hz to 20 kHz unweighted) 150 ohm Phase Response <2.5 degrees (20 Hz to 20 kHz) Dynamic Range 124 dB @ 0 dB gain (20 Hz to 20 kHz unweighted) Maximum Input Level +47 dBu Pad In, @ 1 kHz, <0.1% THD Maximum Output Level +29 dBu balanced, @ 1 kHz, <0.1% THD Common Mode Rejection Ratio <–75 dB @ 1 kHz, 140 mVcm, +6 dB gain Crosstalk <<90 dB, 20 Hz to 20 kHz Phantom Power 48V ±1V High-Pass Filter –3 dB @ 85 Hz 18 dB/octave [Page View]

What are the main features of the Digidesign PRE?

What are the main features of the Digidesign PRE? - Eight high performance, discrete matched transistor hybrid microphone preamplification circuits. - Remote Control with qualified Pro Tools TDM system and Digidesign control surfaces (such as Control 24 or Pro Control). - Maximum fidelity of PRE outputs signals, by keeping preamplification of low level signals close to the source. - Analog outputs utilize industry standard CD-25 connectors for easy connection to Pro Tools audio interfaces or any other recording or mixing medium. Each channel features: • Support for microphone (XLR), line level inputs (1/4") and direct instrument (1/4") • Selectable impedance settings for Mic input • Input gain variable from 0 dB to +69 dB, in approximately 3 dB steps, with an optional –18 dB pad • +48V power for condenser microphones • Balanced Insert points (Send and Return), for easy integration of outboard gear (such as compressors or EQs) • Phase invert • 85 Hz High-Pass Filter • Up to nine PREs are supported through software for up to 72 channels of remote-controlled Mic Preamp channels. • All features are available in Stand-alone mode, making PRE ideal for any recording application. [Page View]

Pro Tools is unable to communicate with PRE #X on MIDI input port XXX, ...

Pro Tools is unable to communicate with PRE #X on MIDI input port XXX, channel X. Please power-cycle the unit and check your connections. If the unit is working properly, communication will automatically be resumed. This has been seen when connecting one or more PRE's to the Digidesign MIDI I/O or other USB powered midi interface with longer midi cable lengths (approx. over 25 feet). Typically, you will not need to use an external power supply when the MIDI I/O is connected to your computer, since the MIDI I/O is powered over USB from your computer. However, when using long midi cable runs or when connecting MIDI I/O to an unpowered USB hub Digidesign recommends using an optional external power supply to power the unit. Any standard 9-12 Volts DC, 500 mA; Polarity: Tip =Plus, Ring = Minus supply will work. If experiencing this error with a third party USB powered midi interface while connected to an unpowered USB hub, try a powered hub, or connecting the interface directly to the computer. [Page View]

How do I calibrate a Digidesign PRE with a 192 I/O?

How do I calibrate a Digidesign PRE with a 192 I/O? Here are the correct steps to calibrate the outputs (assuming PT reference is -18dBFS): 1) Make sure that the outputs of your 192 calibrated properly (-18dBFS 1KHz Sine wave=1.228VAC) 2) Connect the +4dBu outputs of the 192 to the Line/Inst inputs of PRE. 3) Change the inputs of PRE to Line-15K and adjust input trims to "06" for each channel 4) In a new session, create 8 mono Aux tracks assigned to separate mono outputs. 5) Instantiate a Signal Generator on one track, 1kHz Sine wave at -18dBFS. Copy the Signal Generator to the other Aux tracks. 6) Adjust the output trims of PRE so that they are 1.228VAC. Calibration instructions for the 192 I/O can be found at 192 I/O Support > Tech Docs [Page View]

PRE manual states that the PRE is "pin 1" hot. Is this correct?

PRE manual states that the PRE is "pin 1" hot. Is this correct? This is incorrect. The PRE is "pin 2" hot. [Page View]

After updating to Pro Tools 5.3.1, the F3 option on my Pro Control no ...

After updating to Pro Tools 5.3.1, the F3 option on my Pro Control no longer toggles between "fixed" and "velocity sensitive" encoders. Pro Tools 5.3.1 introduced control of PRE. Pressing F3 on Pro Control switches the encoders to control PRE. To toggle between "fixed" and "velocity sensitive" encoders, hold down OPT(ALT) ALL and press F2. [Page View]

Why do I hear clicks when changing the gain on my PRE?

Why do I hear clicks when changing the gain on my PRE? The clicks are a normal and necessary result of the high-quality gain control method used in PRE. The highest priority item for us with PRE was the sonic quality and we worked hard to obtain the performance with the initial design and keep it there through the remote control process. PRE is a precision, transformer-less design, and uses a high-precision differential transistor pair (actually, a bunch on 'em in parallel to reduce noise) as a front end in place of the traditional input transformer. The gain control method used in PRE utilizes relays to place fixed resistors in the feedback path. To vary the gain of the circuit, you cross-couple some feedback from one side of the input to the other. There are very slight DC offsets present across these resistors. When you change gains, some of the DC offset from one side of the circuit is injected into the other side and we get what is called a "step change". Basically, this comes out as a small transient or 'click'. There are plenty of non-remotely controlled mic preamps that utilize a variation of this type of design and they use a potentiometer for gain control, in which case the step change never occurs. On some of these preamps, you can quickly rotate the gain control and hear a "whoosh" or a scratching sound (depending on the type of pot used,) which is really the same artifact in disguise. As a manufacturer, the real problem comes in when you want to remotely vary the gain of one of these circuits. You can easily use a VCA (voltage controlled amplifier) or an MDAC (multiplying digital-to-analog converter,) which delivers the convenience and reduced artifacts of a pot but unfortunately impairs the fidelity and performance substantially. Remember, the audio performance of PRE in terms of noise and distortion is very, very good and due to the high-gain design and critical nature of the circuits, it's very easy to impair this excellent performance with a less-than-excellent gain control method. When it comes right down to it, there are only two methods of remotely controlling a transformer-less mic preamp that I'm aware of. The first might be using an actual servo motor to drive an actual pot. If you can get around the noise of the motor circuit leaking into the sensitive audio electronics, it's a workable solution. Unfortunately, servo motors cost serious money, as do motor drivers, as does the additional power supply required to run them, which would raise the price substantially, not to mention the fact that we would have to fit eight of them in the case and then deal with the extra heat, etc. Then, you have reliability concerns since you now have an electro-mechanical assembly in a critical path. Topping that off, you now have to deal with the error of the pot, which means that unless you calibrate each pot to each mic preamp, you can't have reliable gain amounts, which in turn makes it hard to work in stereo. So the cost, size, complexity and heat all go up while the reliability and accuracy are reduced. The other option is to use relays to switch fixed precision resistors in the circuit. The benefits are many; performance and sound quality are maintained, cost is kept reasonable, reliability is high and gain matching between channels is great. The downsides are simple but livable given the other options; you have fixed gain steps and there are small clicks when changing gain. I believe it is a small price to pay for the increased sonic [More]

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