Classe Audio CDT-300 owner manual Audio delay Digital output

audio delay

digital output

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When a disc has been incorrectly authored, the audio can be out of sync with the video. Audio delay allows you to compensate for this by inserting a delay that repositions the audio in relation to the video and brings them into sync. The delay is adjustable in 10ms steps and operates within a range of ± 200 ms.

Modern video displays make extensive use of video processing (as does the CDT-300 itself ). This circuitry converts standard definition video (480i or 576i, depending on your local broadcast standard) to a format that is compatible with modern fixed matrix displays such as LCD, DLP or plasmas.

However, this conversion process takes some small amount of time, causing a “lip sync” problem between the audio (which has not been delayed appreciably) and the video (which has been delayed for processing). While some people are more sensitive to this problem than others, anyone who perceives a consistent lag between the audio and video will find it quite annoying.

The audio delay function of the CDT-300 addresses this by delaying the audio by anywhere by up to 200 milliseconds. This range of adjustment should be adequate to handle any video processing delay you might find in your system.

Note that the best use of this delay is to compensate for any delay introduced by the CDT-300’s own video processing (assuming you are one of the ones who are sensitive to this sort of thing). The CDT-300 can only delay audio coming from itself, and has no control over (for example) broadcast television you may be watching. If your television introduces enough video processing delay to be noticeable, you would be better off using the audio delay feature of your A/V preamplifier/processor (assuming it has this capability—which Classé processors do have.)

The digital outputs of the CDT-300 can be configured in any of three ways, based on how you plan to use the transport:

•off — selecting this feature will only enable audio output via HDMI.

•raw — which passes along the native signal of whatever disc is playing, whether that is PCM, Dolby Digital, DTS, or anything else. This setting assumes that your external processor can handle anything you might send its way.

•PCM stereo — if the soundtrack you are playing contains multichannel information, it will be “downmixed” to a two-channel PCM signal that would be compatible with stereo playback, or further processing with Dolby Pro Logic II or DTS Neo:6 (as examples).