What can be the causes of sound dropouts?
If sound dropouts occur from a certain position of the MASTER control on AMP1, this is a sign that the protection circuit of AMP1 is taking effect. As the name suggests, this feature protects the amp from damage that could be caused, for example, by connecting too low an impedance to the speaker out, or by a short circuit in the cable or the speakercabinet, etc.
When connecting a cabinet
If a speaker cab is connected to the speaker out of the AMP1, you should first check the impedances. What is the impedance of the cabinet, and to which SPEAKER OUT of the AMP1 is it connected? The impedance of the cab should match the impedance of the speaker output.
If this is not possible (e.g., because several cabs are connected in series or in parallel and the total impedance is neither 8 ohms nor 16 ohms), make sure that the total impedance of the connected cab(s) is greater than - or equal to - the impedance of the speaker output. The overall impedance of the cab(s) must never be less than the impedance of the speaker output!
If the impedances are correct, tripping of the protection circuit could be caused by a short in the cabinet or in the speaker wire. Please check the cables and cabs used in this instance.
When connecting a load box or similar
If a load box or similar is connected to the SPEAKER OUT of the AMP1, the load box may not perfectly reproduce the speaker load specified. This can also trigger the protective circuit. In this case, the AMP1's MASTER should be turned down so far that the protection circuit is no longer activated.