There are lots of great questions here.
1. DVI can connect to an HDMI with an adapter (or DVI-to-HD cable). However, the audio source for the DVI device will be separate, since DVI only carries the HD picture, and not audio.
2. HDCP is High Definition Copy Protection, and our models have it. The "HDCP handshake" is a connection between two HD devices that give each other permission to transmit a signal. If one side is not HDCP compliant (or it has been disabled), the picture or audio may not be sent. All legitimate cable/satellite boxes, Blu-Ray players and other devices will work just fine.
3. VHS or DVD players, if it has an HDMI port, would work just fine. VHS with component or composite would not have the "handshake" at all, so the signal would just pass through.
4. Headphone jack have a "variable" volume control, which means there is an amplifier that can raise or lower the volume. The audio output is a similar port (physically), but the signal is "fixed", and designed to work at a standard level or audio bars, receivers or amplifiers. No volume control changes on a "fixed" port, only variable ports.
Thanks for your interest in Samsung products. If we can help further, please reach out and let us know how.
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