Is It a Good Practice to Use the Standby Switch on an All-Tube Electric Guitar Amplifier?

One of the common questions faced by electric guitarists is whether it is advisable to use the standby switch on their tube amplifiers. This article explores the pros and cons of using a standby switch, drawing insights from decades of experience and modern technical understanding.

Key Benefits of Using the Standby Switch

Warm-Up Period: The primary benefit of using a standby switch is that it allows you to warm up the tubes before applying full power to the amplifier. This practice is crucial as it helps extend the life of the tubes, ensuring they operate at optimal performance. By gradually heating up the tubes, you reduce the amount of stress on the components and improve their lifespan.

Silence During Setup: Another significant advantage is the ability to mute the amplifier during setup. This prevents loud pops and potential damage to the speakers, which can occur when you connect or disconnect instruments. This feature is particularly useful for concert venues, recording studios, and rehearsals.

Reasons Against Using the Standby Switch

Despite the benefits, there are several reasons why using a standby switch might not be the best practice for all tube amplifiers:

Reduced Component Lifespan: According to RCA Transmitting Tubes Technical Manual (page 71), tubes should not be subjected to voltage until the cathodes have reached normal operating temperature. For receiving tubes, which often operate in modern guitar amplifiers, this temperature is not necessary. Overheating rectifier tubes in standby mode can lead to reduced lifespan.

Noisy Transitions: When using a standby switch, there can be a noticeable thump in the speaker when you switch on the amplifier. This noise can be distracting and potentially damaging to the speaker if it is not handled properly.

Expert Opinions on Standby Switch Usage

Various experts such as WamplerPedals and Merlin Blencowe offer different opinions on the use of standby switches:

Kevin O’Conner (London Power): He suggests leaving the standby switch in the operating position and only using it as needed, such as when flipping the power switch. He also recommends rewiring the switch to control just the screen circuit, which can significantly reduce switch stress and maintain the output tubes at zero plate current.

Merlin Blencowe: He points out that standby switches can reduce the lifespan of rectifier tubes, especially if the switch is between the rectifier and the main capacitor bank. He also notes that some manufacturers have made mistakes in implementing standby switches, leading to failures.

Final Thoughts on Standby Switch Usage

The decision to use a standby switch ultimately depends on your individual situation and preferences:

Positive Practices: If you choose to use a standby switch, be mindful of the potential drawbacks. Always let the amplifier warm up before switching to full power, and consider reconfiguring the switch to minimize switch stress and component wear.

Negative Practices: For many guitarists, the standby switch is unnecessary and can lead to negative consequences. It is often better to hardwire a bypass and remove the switch entirely, especially in an all-tube amplifier.

Ultimately, the choice is yours, but it's essential to understand the implications of using or not using a standby switch. As with many aspects of guitar playing, the key is balance and informed decision-making.