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Review: Digidesign Pro Tools HD1

Anyone following the world of digital audio workstations has surely heard of the new Pro Tools HD systems Without question, this is a major upgrade for Digidesign. The focus this time around is hardware. And the impetus is the quest for higher sampling rates.

Anyone following the world of digital audio workstations has surely heard of the new Pro Tools HD systems (starting at $7,995). Without question, this is a major upgrade for Digidesign. The focus this time around is hardware. And the impetus is the quest for higher sampling rates.

Like Digidesign’s MIX systems, the HD1 system uses an HD Core card as the heart of the audio processing, mixing and DSP. The new product line also includes the 192 I/O and the 96 I/O audio interfaces amongst others. As the names imply, these are the maximum sampling rates for each box. Like most things in life, more money buys more power. This is definitely the case with the 192 I/O.


While HD refers to “high definition” audio, it could also mean more “hard disk” space. Recording at 24-bit/192 kHz requires about four times the hard drive space as 24-bit/44.1 kHz. As we all know, prices for hard drives have dropped dramatically. Conversely, the need for more storage has risen accordingly.

Even as MP3 files run rampant over the Internet, high definition audio is here to stay. While the 192 I/O is Digidesign’s flagship interface, it is also twice the price of the 96 I/O. And not all people may need this much power. At this point in the game, it looks like 96 kHz will be the next stopping point for the audio industry. For these reasons, I chose to look at Pro Tools HD1 with the 96 I/O. Not to mention, it is the most affordable way to enter the HD family.

Installing the system was a snap. Put the HD Core card into one of the computer’s slots, connect the DigiLink cable from the card to the interface, install Pro Tools 5.3.1 software and you are ready to go.

The 96 I/O is an attractive 2RU interface. The front panel has LEDs that indicate sampling rates from 44.1 kHz to 96 kHz, sync modes for different clock sources, and a Loop Master indicator for multiple interfaces. For metering, there are 16 channels of four-segment LEDs measuring input or output signals.

Flip the box around and get wired up. The eight analog inputs and outputs use balanced 1/4-inch TRS jacks (the output connectors also handle unbalanced mono phone plugs). For digital applications, there are pairs of AES/EBU, S/PDIF and eight channels of ADAT I/O.

The ADAT optical ports may be used simultaneously with the eight channels of analog I/O, or switched into two-channel S/PDIF optical mode. The ADAT optical can operate simultaneously with either the AES/EBU or S/PDIF ports. Unfortunately, you cannot use AES/EBU and S/PDIF inputs simultaneously. I found this disappointing!

Rounding out the interface’s back panel are I/O for word clock, Legacy Peripheral and Expansion ports for other compatible Digidesign hardware, two DigiLink connectors and a socket for the AC power cord. All together the 96 I/O has 20 inputs and outputs and handles 16 channels simultaneously.

The unit’s operating levels are switchable between +4 dBu and -10 dBV from Pro Tools software.

As for the HD Core card, Digidesign states that it has twice the processing power as the MIX Core card. With nine Motorola 100 MHz DSP chips, this PCI card supports up to 32 channels. When used with the 96 I/O, it handles 96 tracks at 44.1 kHz/48 kHz and 48 tracks at 96 kHz. Lastly, there is a serial port on the card for use with Digidesign’s MachineControl and the SYNC I/O peripheral.

Pro Tools HD ships with software version 5.3.1. While not a major release, this upgrade adds features such as new DigiRack plug-ins, increased I/O capability, a new HTDM plug-in format, additional Avid Compatibility and Networking functions, support for the new Digidesign PRE remote-controlled mic-preamp, auto-detection of the SYNC I/O hardware and many other features. Users familiar who cut their teeth on previous versions of Pro Tools will have no problem navigating this release.

In Use

When digital audio made the jump from 16 bits to 24 bits, the improvement in the dynamic range was immediately noticeable. However, I did not find the change from 44.1 kHz to 96 kHz as dramatic. Yes, there is more “air” and 3-D transparency, but the difference is fairly subtle. Moving up to a sampling rate of 192 kHz may be a different ball game.

Source material for the evaluations included acoustic and electric guitars, various percussion instruments, synths, samplers and voice. My initial impression was that higher frequencies seemed to benefit the most from the higher sampling rates. But that may be debatable.

Unfortunately, I was not able to do a blowout A/B comparison between Digidesign’s MIX and HD systems. Having used both platforms, it is obvious that the 96 I/O has better converters than the 888/24. There is much more detail and clarity. Keep in mind that converters are only part of the picture. The other hidden ingredient is the quality of the analog circuitry in the hardware design. It is obvious that Digidesign did its homework on this one.

As for MIDI users, there is not much new with Pro Tools software 5.3.1. The good news, though, is the arrival of Digidesign’s MIDI I/O interface (to be covered in a future review). As part of the HD family, this interface along with a future version of Pro Tools will support Digidesign’s MIDI Time Stamping. Promising to tighten up the accuracy of MIDI data, Time Stamping sends MIDI events in packages ahead of time, rather than serially. This should yield a MIDI response time of less than a millisecond!

Users looking to expand their HD1 system have numerous choices. Up to six Process (known previously as DSP Farm) cards may be added to maximize DSP plug-in power. For more I/O options, additional 96 I/O or 192 I/O interfaces can be daisy-chained together.

And for users who want to integrate older Digidesign hardware, the Legacy Peripheral port provides connectivity. As to be expected, sampling rates on older gear is limited to 48 kHz. Start small and build your Pro Tools DAW as needed.


It was inevitable that Digidesign would upgrade its product line to accommodate high definition audio. In fact, many people wondered why it took them so long. The wait was well worth it.

While the HD systems are not inexpensive, Digidesign has maintained the original price point of the MIX systems. For under $10,000, the HD1 and the 96 I/O buys you state-of-the-art recording, editing and mixing. Now that is something to think about.


Product Points

Applications: Computer-based recording, mixing and mastering.

Key Features: Non-destructive high definition digital recording; integrated MIDI sequencing; powerful TDM II plug-in architecture; surround sound mixing; post production functions with Avid Picture Options

Price: $7,995 – Pro Tools HD 1 (includes one HD Core card and Pro Tools 5.3.1 software); $1,995 – 96 I/O Interface

Contact: Contact: Digidesign at 650-731-6300


+ Pristine high definition recording
+ Higher track count and I/O capability; expanded routing flexibility
+ Full session compatibility with systems running Pro Tools 5.1 software or higher; supports all older Pro Tools sessions
+ Attractive and ergonomically designed hardware interfaces


– HD hardware not compatible with MIX systems
– Additional hard drive space needed for high definition recording
– Smaller project studios may not be able to afford HD systems

The Score: A must-have upgrade for anyone looking to be current with Digidesign’s next-generation audio systems.