Manual

Warning regarding the proper use of a loadbox with a tube ampliﬁer

2 Which output volume for my ampliﬁer ?

The correct use of your ampliﬁer with a loadbox requires some precautions. Because of the fact that you may

be playing "silently," it is much easier to accidentally run your ampliﬁer beyond the reasonable limits set by the

manufacturer than when you are using an actual speaker cabinet. This can lead to faster tube wear and, in

some cases, to more serious inconveniences.

During the ﬁrst tests at high volume on the ampliﬁer, monitor the color of the

tubes and the general state of the ampliﬁer. Red-glowing tubes or any appear-

ance of smoke are signs of a problem that could lead to partial or complete

destruction of the ampliﬁer.

Keep in mind that the "sweet spot" — the perfect running point of the ampliﬁer, the one that will give you the

tone you are looking for — is rarely obtained at maximum volume. In addition, the volume control of the ampliﬁer

is usually logarithmic, which means that the volume goes up quickly on the ﬁrst half of the potentiometer’s

rotation, reaches its maximum at 12 o’clock, and will not change much beyond that point. Therefore, you can

reach the maximum volume of your ampliﬁer even if the volume potentiometer is not set at maximum.

By reaching the maximum output power of your ampliﬁer, you will hear a lot of distortion, which may not

sound as good as you could hope. In fact, most ampliﬁers do sound rather poorly at maximum volume. Always

keep in mind that your ampliﬁer may not have been conceived to be used at maximum volume for a long

time. Running an ampliﬁer at high volume will cause premature wear of the tubes and possible malfunctions or

damages at the output stage.

The fact that the volume control of your ampliﬁer is not set at maximum does

not mean your ampliﬁer is not running at maximum volume. A good habit is

to keep the usual volume setup you would use in rehearsal or on stage, rather

than just following what the volume potentiometer indicates.

12 Two Notes Audio Engineering TORPEDO Live