||Details and Specials
Limiting occurs when the input level exceeds the threshold level
Control range from +20 dB to -10 dB
With the fast attack time setting that are necessary to avoid overloading the
input of an a/d converter, the limiter responds within approx. 8 µs. With
low frequency signals, this may cause a hard edge in the signal that might produce
a short but audible distortion. The effect disapears if the attack time is in
the range of 1 ms; however, such attack time is way to long to avoid overloading
of converters by fast peaks. This is a physical problem that occurs with fast
attack times and not a problem of a particular limiter. The LF-Attack pot smoothes
the hard edge of low fequency signals. Actually, the pot controls the frequency
range of the smoothing and not the amount. If there is a problem with LF distortion,
turn the LF-Attack pot to find the best position for the particular signal.
You may know the effect by 'Auto-Release' settings of compressors. With the TM215b
you are able to determine the amount of auto-release by the position of the pot.
In the OFF position, only the static release pot determines the release time.
The more the dynamic release pot is turned to the right, the more the release
time is modulated by the density of the program. The static release control always
determines the minimum release time while the dynamics release pot determines
how much the release time is extended for high density signals.
The range and the behavior of the static and dynamic release can be modified
by jumpers on the module pcb. It is possible to change the range of both range
to half or twice the factory standard setting. It is also possible to modify
the law of the release time from dB-linear to dB-linear for 3 dB and very fast
for higher levels.
Another set of jumpers determines if the gain pot is affected by the bypass switch
or not. With the factory standard setting, both, limiter and output gain pot
are bypassed. With the alternate setting, the bypass only disables the limiter
section while the gain control is always active.
||Vernier: Threshold Fine Control with +/- dB Range and
||Low Frequency Attack Control, Range from
OFF to 6,
lowers the static attack time for low frequencies to reduce distortion of bass
signal with fast attack times. The position determines the frequency where the
effect takes place.
||Static Attack Control, Range from .02 ms to 7 ms for
10 dB attenuation
determines the response time of the regulation independent of the frequency
||Static Release Control, Range from 50 ms
bis 3 sec, determines the fade up speed when the level drops down
||Dynamic Release Control - Range from OFF to 6
determines how much the release time is modulated by the density of the program.
||Gain Control with calibrated center position and center detent,
control range +/- 10 dB
The gain control affects the output level post limiter
||The LED-Chain shows the actual gain reduction,
5 LED's, display range from 1 dB to 10 dB