Shure A15AS Switchable Attenuator (15/20/25 dB) - Clean Level Control

In this review the Shure A15AS Switchable In-Line Attenuator is evaluated as a simple, rugged solution for taming high-output microphones and preventing input overload on mixers or recorders. The bottom line: it is for engineers, live sound techs, and field recordists who need reliable, in-line attenuation without changing mic tone or losing phantom power. The unit's selectable 15, 20, or 25 dB reduction and pass-through of phantom power make it a small tool with a specific, practical purpose for high sound pressure level situations.

Key Features

• Switchable attenuation: The three-position 15, 20, and 25 dB settings let the user precisely reduce signal level to prevent input overload without guessing.
• Phantom power compatibility: It passes phantom power so condenser microphones remain powered and functional when the attenuator is inline.
• Balanced signal handling: Designed for balanced microphone or line-level signals, it maintains signal integrity during attenuation.
• Compact package: Small physical dimensions make it easy to place inline on stage or in a recording setup without adding bulk.
• Durable build: As noted by customers, the construction meets Shure quality norms and holds up in professional use.

Who It's For

The A15AS is aimed at audio professionals and serious hobbyists who encounter high-output dynamic or condenser microphones that can overload a mixer or recorder input in loud environments. Live sound engineers, location recordists, and anyone dealing with unpredictable SPLs will appreciate the quick attenuation choices and the ability to retain phantom power.

Those who should look elsewhere include users needing multi-channel attenuation, digital pad options inside a mixer, or advanced impedance matching features; the A15AS is a single-channel, inline passive attenuator designed for straightforward level control rather than complex signal routing.

Pros & Cons

Pros

• Reliable three-step attenuation provides immediate control over excessive levels without degrading the tone.
• Passes phantom power so condenser mics remain powered and ready to use inline.
• Customers report low added noise and effective reduction of radio-frequency interference in practice.

Cons

• Only a single-channel inline solution, so multiple microphones require multiple units or alternate routing.

Specifications

Product Type	Microphone attenuator
Attenuation Levels	15 dB, 20 dB, 25 dB
Phantom Power	Passes phantom power
Package Dimensions	2.032 cm x 2.54 cm x 9.398 cm
Package Quantity	1
Country of Origin	Mexico

Our Verdict

The Shure A15AS is a focused, well-made inline attenuator ideal for live and location work where protecting inputs from high-output mics matters. It offers straightforward, selectable attenuation and passes phantom power, making it good value for users who need reliable single-channel level control without signal degradation.

Frequently Asked Questions

Can I use the A15AS with condenser microphones?
Yes, it passes phantom power so condenser microphones remain powered when placed inline.

Will attenuation change my mic tone?
The unit is passive and customers report it reduces level without noticeable signal degradation or tone loss.

Is it suitable for line-level signals?
Yes, it can be used to reduce line-level mixer outputs to prevent overloading aux-level recorder inputs.