ensure the shortest possible stub length. Using multiple terminations is wrong, both because twice 50 Ohm in parallel gives 25 Ohms (wrong !) and also because it increases loading on the source.

H8000 and H8000A are shipped with termination in place meaning that they can be used at one end of a Word Clock cable without changes. To use them in the middle of a chain the termination should be disconnected by removing the black jumper on the motherboard directly behind the Word Clock connector.

H8000FW has no internal termination and can be used in the middle of a Word Clock cable without change. To use it at the end of a chain, external 50 Ohm termination must be applied. To do this, you will need a BNC T piece as shown above and a 50 Ohm terminator as shown on the right. These may be supplied with the H8000FW or obtained from one of many suppliers. Connect the T piece to the Word Clock input, the cable end to one side and the terminator to the other.

WORD LENGTH (BITS)

Input Word Length

As mentioned in the introduction to this section, the H8000 assumes that the signals at the digital inputs are all 24-bit. Things work out regardless of the actual word length of the input signals because, for example, the 16 bits in a 16 bit signal correspond to the 16 "most significant" bits in a 24 bit signal. The 8 "least significant" bits are left "blank," to be filled in by subsequent processing.

If, however, the device sending the H8000 digital signals supports the protocol, you can see the word length at the inputs to the H8000. Go to the format menu page in the SETUP area. The fields on the left display the input word length (16 bits, 24 bits, and two unlocked signals in this case). The H8000 user can display and change these settings on Digital channels 1-8,

while H8000A and H8000FW can only show channels 1-4.

If the input bits are unknown as in the case of an S/P DIF input, the field reads, quite logically, "unknown." If a digital input is unlocked (not valid or not connected), the field will read "**."

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