Shure RPM89/PRE – Class A Discrete Preamp for VP89 Shotgun Microphones

Product Overview

The Shure RPM89/PRE is the replacement Class A discrete preamplifier for the VP89 modular shotgun microphone system. Compatible with all VP89 capsule lengths — RPM89S (short), RPM89M (medium), and RPM89L (long) — as well as legacy SM89 microphone capsules, the RPM89/PRE is the active electronics core of the VP89 system. It is designed for professional A/V media production, broadcast, and government sound capture applications where transparent, low-noise amplification and superior RF immunity are system requirements.

Product Description

The RPM89/PRE delivers a Class A, discrete circuit topology with no crossover distortion and minimal harmonic and intermodulation distortion, providing transparent signal amplification for demanding production environments. A two-position low-frequency response switch allows the operator to select flat response (100 Hz rolloff point) or a 12 dB/octave low-frequency rolloff below 200 Hz — useful for reducing HVAC rumble and low-frequency room noise in conference room, auditorium, and broadcast settings. Output impedance is 115 Ω, and the unit operates on phantom power from 11–52 V DC (IEC-61938), drawing less than 2.0 mA. The VP89 preamp provides common mode rejection of ≥70 dB and is designed for extremely low susceptibility to GSM and RF interference. Aircraft-grade aluminum alloy construction is matched to the VP89 capsule housing for durability in field production and fixed installation use.

Key Features

• Class A Discrete Circuit — Pure Class A topology delivers transparent, extremely fast transient response with no crossover distortion and minimal harmonic and intermodulation distortion.
• Selectable Low-Frequency Response — Two-position switch selects flat response or 12 dB/octave low-frequency rolloff below 200 Hz, useful for rejecting HVAC and room noise in fixed installation and broadcast environments.
• VP89 and SM89 Capsule Compatibility — Accepts all three VP89 capsule lengths (RPM89S, RPM89M, RPM89L) and is forward/backward compatible with Shure SM89 shotgun microphone capsules.
• Superior RF Immunity — Designed for extremely low susceptibility to radiated and conducted hum, GSM, and RF interference; common mode rejection ≥70 dB across 20–20,000 Hz.
• Wide Phantom Power Range — Operates on phantom power from 11–52 V DC (IEC-61938); performs optimally at 48 V DC but compatible with lower-voltage supplies, drawing <2.0 mA.
• 115 Ω Output Impedance — Low output impedance for compatibility with a wide range of professional mixing consoles and audio interfaces; Shure recommends minimum 1000 Ω input impedance at the preamp input for optimal dynamic range.
• Aircraft-Grade Aluminum Construction — Durable charcoal-grey metallic painted aluminum alloy housing with stainless steel screen; resists wear and temperature extremes in field production environments.

Typical Applications

• Broadcast studio — replacement or spare preamplifier for VP89 shotgun microphone systems used in television and radio production
• Government space — A/V media production and official proceedings capture requiring low-noise, high-rejection directional microphone systems
• Auditorium — fixed installation shotgun microphone applications where the capsule is separate from the preamp for serviceability
• Training room — A/V production and distance learning capture using modular VP89 shotgun systems

Technical Specifications

Frequently Asked Questions

Is the RPM89/PRE compatible with SM89 capsules?
Yes. The VP89 preamplifier is designed for forward and backward compatibility with the Shure SM89 shotgun microphone. SM89 capsules and VP89 preamplifiers can interchange.

Which capsule is appropriate for which pickup distance?
The VP89L (long, RPM89L) provides the narrowest acceptance angle for distant pickup. The VP89M (medium, RPM89M) offers a balance of reach and flexibility. The VP89S (short, RPM89S) provides the widest pickup angle for shorter capture distances. Capsules are sold separately.

Can the RPM89/PRE operate on 24 V phantom power?
Yes. The unit operates on phantom power from 11–52 V DC, but Shure specifies optimal performance at 48 V DC. Lower supply voltages result in slightly reduced headroom and sensitivity.

What is the recommended minimum load impedance?
Shure recommends a minimum input load impedance of 1000 Ω at the connected console or audio interface preamplifier for optimal maximum SPL, clipping level, and dynamic range.