Crown Audio VT-15 Stereo Amplifier User Manual


 
D.W. FEARN
VT-15 Recording Channel
19
4.
OPERATION
INITIAL SET-UP IS CRITICAL
for getting the best performance from your VT-15!
The VT-15 has tremendous versatility, but with that versatility comes the potential for for very
unpleasant sound. Think of the VT-15 as a small studio chain in one box: mic preamp, com-
pressor, and equalizer. In most studios, these would be three separate pieces of equipment
and you would patch them together in a chain feeding your recorder. The VT-15 is the same
concept, except that the “patching” is done inside the VT-15. And just like a bad gain struc-
ture in your mic pre/comp/eq will seriously degrade the performance, the same is true with
the VT-15. Improper gain structure, in the VT-15 or in separate units, will increase the
noise, reduce the headroom, and increase distortion. So follow these steps for the initial
set-up of the VT-15. They provide the proper starting point, and optimize the gain structure
for best performance.
Figure 1. VT-15 front panel controls and indicators
A Note about Powering Down the VT-15
Because the VT-15 is designed so that the most often used settings do not energize the cor-
responding internal switching relay, when you turn off the power to the unit, it will revert to
the Mic input, whether you were using Mic or Line. If you are feeding a line-level signal into
the VT-15, removing the power will immediately switch it to Mic input. Since the tube fila-
ments and power supplies will continue to operate for about 20 seconds after power is turned
off, the level could increase significantly during that time. Be sure to turn down the Preamp
Gain control before turning off the Power switch. Or make sure that the VT-15 will not be
feeding your monitors on shut-down. This will not hurt the VT-15, but it could damage your
hearing or your speakers if the level were to suddenly jump 50dB!