Crane Song HEDD 192 - Manual (Page 6)

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THE CONTROLS
SAMPLE RATE SWITCH
The A/D clock rate can be set from 44.1Khz to 192KHz or an external WC reference. The units
taht were shipped going to 96k only will defult to 44.1K if rates above 192k are selected. When a
valid word clock is applied and WC is selected a red light next to the switch will light indicate
lock. If lock is lost, HEDD-192 will default to 44.1Khz and the light will be off. Whenever the
sample rate is changed, the A/D convertor is re calibrated. This will keep the convertor working
as accurately as possible.
OVER RESET BUTTON
Clears the overload LED. It also clears the peak memory value.
BYPASS SWITCH
The switch enables or disables the DSP process. There is a small time lag when the process is
turned on and off to reduce the possibility of clicks in the audio.
INPUT SWITCH
The input switch selects between the AES and S/PDIF inputs
TRIODE
The triode function creates a triode like harmonic structure. This process contains strong even
order harmonics, but is not strictly even order. This affects the bottom of your signal by fattening
it up and it should be noted that even
order harmonics are difficult to hear. The harmonic struc-
ture changes with signal level and the amount of process being applied, just like it does in a tube
and the analog world. This control does make a low level zipper noise when it is turned
PENTODE
The pentode function creates mostly third harmonic information but contains some higher order
odd harmonics depending on the signal level and the amount of process. It is like driving a
pentode into over load. The pentode process makes things sound brighter, and brings out detail.
This can also be described as a compression effect. The pentode process affects the triode
process because the two processes are in series.
TAPE
The tape function emulates magnetic recording tape. Tape distortions are odd harmonic, starting
with the third and fifth. As you increase the level on tape the harmonic content increases and
higher odd harmonics are added. A tape recorder also contains record and reproduce equaliz-
ers that modify the harmonic content. The result is a sound that fattens up the bottom and
midrange of a recording and as you increase the process. There can be loss of hi frequencies
with respect to low frequencies if driven far enough, and the high frequencies start compressing
sooner then the low frequencies. This is a result of the compression function and eq. curves in
the process. The compression also squashes peaks and results in a higher average level. The
tape process is in series after the triode and pentode processes and thus modifies them both.
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