Q: When I turn my SWR amplifier's power switch to the "On" position, I hear a "pop" sound through my speakers.
A: This may be the top concern among SWR owners. Unfortunately, there is no effective way to resolve this issue without taking measures that would be detrimental to both the tone quality and reliability for which SWR amplifiers are known. Although many users consider the "pop"—a transient heard at power-up—to be disconcerting, it is normal and will not damage your loudspeakers.
Elimination of the power-on transient would require additional circuitry and the inclusion of a component called a "relay" (relays are known to degrade signal quality and are prone to failure). When a relay failure occurs—which is not unusual—it can cause the amplifier to completely lose output, requiring significant downtime for repair. Hence, SWR chose not to incorporate such components into its amplifier designs. If you still wish to avoid hearing the power-on transient, the following actions may be taken:
• For amplifiers with a speaker on/off switch, set the speaker switch to the "Off" position, power on the amplifier, then set the speaker switch to the "On" position.
• For modular amplifiers without a speaker on/off switch, connect your speaker cable to the amplifier's speaker outputs after power up if you choose. It's important, however,to make sure that you aren't playing through the unit and that no signal is present when you make the connection.