Technical data
29
Ratio Feedback
The alpha compressor works with a soft knee characteristic and increasing ratios at rising gain
reduction values. The scale on the front panel is based on a measured gain reduction of 6 dB.
Strictly speaking, the ratio values become noticeably higher on stronger reductions: If there is
17 dB of gain reduction the ratio value will shift from the printed 1:2.5 to actual 1:4.5 after all.
Anyhow, the scale is optimized to the lower gain reduction settings as these are the ones most
frequently used in mastering applications.
Ratio Feed Forward
In feed forward mode the ratio characteristics dier strongly from those in feedback mode. Al-
though they remain quite comparable up to a value of 1:1.5, the dierences become extremely
obvious at higher settings. The lower curve shows the radical eects: An input level of 0 dBu is re-
duced to -8.3 dBu, and an input level of +10 dBu is reduced to -15 dBu (!) after processing. Extreme
settings like these can only be achieved with a feed forward compressor, and they can result in
very wild eects.
REFERENCE – Ratio Feedback & Ratio Feed Forward