AC-AUDIO Tube G52 Pro Руководство пользователя - Страница 9

Просмотреть онлайн или скачать pdf Руководство пользователя для Усилитель AC-AUDIO Tube G52 Pro. AC-AUDIO Tube G52 Pro 11 страниц. 2 channel tube preamp

Печатать страницу

Increasing the input gain pushes more signal level into the valve, thus generating more

harmonic distortion and creating that special "valve sound". At the same time the output

level can be turned down to preserve the same level at the outputs, so a choice of sounds

is available. For a more pronounced valve sound, turn up the input gain and reduce the

output gain, and vice versa for a cleaner sound.

Increasing the Input Gain control setting will tend to push the signal towards and

possibly over the compression threshold setting, so this control will have a pronounced

effect on the amount of compression taking place.

5.4 90 Hz Low Cut Filter.

The low cut (high pass) filter switch restricts the low frequency response of the preamp,

to remove rumble or LF noise from the signal effectively. The filter is useful in restricting

"popping" on vocals or even low frequencies caused by contact with microphone stands or

microphone cables.

Popping is an undesirable thump that is caused by close-miking certain spoken or sung

letters, such as "P" or "B". These particular letters cause a sudden expulsion of air that

result in an audible thump. As this thump has a lot of low frequency content the high pass

filter can help to reduce the problem, as using a bop cover suspended in front of the

microphone. The 90Hz filter is active on mic, line and instrument inputs.

5.5 Drive and Peak LEDs.

The yellow Drive LED provides a visual indication of the signal level through the valve

stages, and therefore the extent of "warming" or valve character being showed. The Drive

LED will illuminate gradually when the input level or gain is increased, over the range 8dB

to +18dB.

The red Peak LED operates as a conventional warning that clipping is about to occur.

The operating level of the entire signal chain is monitored, and the LED illuminates when

there is less than 6dB of headroom remaining. Normal operation would be to set the input

gain so that the Drive LED is illuminating regularly, with occasional lighting of the Peak

LED on transients.