McDowell Signal Processng ANALOG-CHANNEL

AC1
Analog Channel's AC1 is a "class A" gain stage - the premium amplification design in the analog world for audio production. AC1 gives control over many parameters previously unavailable to the common user. This flexibility allows for a number of ways to improve a mix.

Pure digital tracks can suffer from harsh digital clipping. AC1 acts as a 'digital pre-amp' allowing even excessive amounts of gain without digital distortion. A drive control determines where the audio 'sits' in the saturation/compression region, and even the attack and release times of the distortion character are adjustable. And AC1 is the most efficient McDSP plug-In ever - up to 24 mono channels or 16 stereo channels on a single MIX dsp chip. Place it across the entire mix to create a custom analog console.

The Analog Channel Emulator AC1 plug-In is an analog amplifier, or analog channel. Instead of allowing the user to drive signal levels into digital clipping at 0 dB, the AC1 plug-In provides gentle, continuous soft-limiting/compression (or saturation pending the attack/release times), at a signal level selected by the user. AC1 can be used as a fail-safe for preventing unwanted clipping, or as a creative tool to smooth/warm-up digital tracks and provide otherwise unavailable analog character to a digital system. Even the sound of large analog mixing consoles can be closely matched using the AC1 plug-In.

AC2
The Analog Channel Emulator AC2 plug-In is an emulator of the most popular analog tape machines (and tape mediums) known to the professional audio recording industry. Playback systems from Studer, Otari, MCI, Ampex, Sony, and Tascam are available in a single 'reproducer'. Modern and vintage tape formulations, IEC standards, and tape saturation release (not found on any other 'reproducer') round out the control section of the world's most flexible tape playback/recorder.

Standard tape machine parameters such as bias, playback speed, and IEC1/2 equalization are provided. Control well beyond the limits of the 'reel-world' devices includes adjustable low frequency roll off and head bump - independent of playback speed. You can select from several playback head types, and even control the rate at which tape saturation is dis-engaged. And instead of frequency sweeps and test tones, the playback head and tape saturation responses are displayed in realtime - updated with every control change.

Tape Formulations
In the world of tape, not only does the tape machine influence how the audio is heard, the tape medium itself is also a sonic factor. A great number of tape formulations have been created since the tape machine was first developed. The AC2 plug-In has consolidated them all into two generally accepted formulation categories:

• Modern: current manufacturing technologies create a tape with a much greater dynamic range than earlier formulations. These tapes have a large linear region, and hence have a smaller non-linear (saturation) 'character'. This makes for recordings as true as possible to the original material.
• Vintage: older tape mediums tend to have less dynamic range, and suffer from greater distortion/saturation. These tapes, however, have 'character' that newer ones do not, and have been used with great success in recording audio.

A conventional tape machine (recorder or reproducer) requires a great deal of maintenance, to insure the unit performs consistently. This requirement is complicated by the subjective criteria of each user - the 'optimal' setup may differ from project to project.

Fortunately in the digital domain, the 'good' things about tape machines and the tape medium can be modeled, and the models can perform consistently over time. Additionally, the 'optimal' setup is only a few control changes away (instead of a tedious calibration session).

Compatibility

• Operating System: Analog Channel is compatible with both Mac OS 10.4.x and Windows XP.
• Configurations: Analog Channel is available in TDM, RTAS, and AudioSuite configurations.
• Applications: Pro Tools™ 7.x or higher is required for TDM, LE, and M-Powered systems.  Additionally, a Third Party software application that supports the Digidesign TDM, RTAS, or AudioSuite plug-in Standard may be supported.

Performance

• AC1 - Up to 56 mono (or 34 stereo) channels on a single HD Accel dsp at 48kHz. Up to 28 mono (or 17 stereo) channels on a single HD dsp at 48kHz.
• AC2 - Up to 18 mono (or 8 stereo) channels on a single HD Accel dsp at 48kHz. Up to 9 mono (or 4 stereo) channels on a single HD dsp at 48kHz.