Accuphase F-25V/F-25VM (2001)

Name: Accuphase F-25V/F-25VM
Brand: Accuphase

Multi-channel divider for active crossover systems, released February 2001.

Overview

The Accuphase F-25V and F-25VM are multi-channel dividers designed for active speaker management, manufactured by Accuphase Laboratory, Inc. (originally Kensonic Laboratory, Inc.). Released in February 2001, the F-25V supports switchable filter slopes of 12dB/oct., 18dB/oct., or 24dB/oct., while the F-25VM is a specialized version fixed at 18dB/oct. due to its dedicated DN-25VM filter amplifier unit. The F-25V uses a modular design with detachable filter and line amplifier units, allowing expansion from a standard 2-way configuration to up to 4-way systems using optional components. Both models feature fully balanced inputs and outputs, Gaussian-type filter curves, and GIC-type filter circuits for precise frequency division.

Specifications

Maximum Input Level	7.0V (Balanced/Unbalanced, ≤0.01% THD, 20Hz–20kHz)
Total Harmonic Distortion	0.003% (20Hz–20kHz, 2.0V output)
Frequency Response	20Hz–20kHz +0/-0.2dB; 4Hz–180kHz +0/-3.0dB
Gain	0dB
Crossover Frequency	Adjustable via interchangeable board; 21 standard points
Crossover Characteristic	-3.0 dB ±5%
Slope Characteristic	-12dB/oct., -18dB/oct., -24dB/oct. (switchable on F-25V)
Input Impedance	Balanced: 40kΩ, Unbalanced: 20kΩ
Output Impedance	Balanced: 50Ω, Unbalanced: 50Ω
S/N Ratio	100dB (0.5V output, IHF-A weighted)
Minimum Load Impedance	600Ω (Balanced/Unbalanced)
Attenuator	0dB/10dB (per line amplifier via internal switch)
Level Adjustment	Per band, L/R independent: 0 to -8dB (0.5dB steps), -8dB to -20dB (1dB steps), -∞
Power Supply	100VAC, 50Hz/60Hz
Power Consumption	32W
Dimensions	475mm (W) × 170mm (H) × 394mm (D)
Weight	15.4kg

Design

The F-25V integrates filter and line amplifiers in a modular, panel-mounted unit for easy serviceability and expansion. It uses a GIC-type filter circuit with Gaussian characteristics and an s-Gretta current feedback amplifier for stable high-frequency phase response. Each band includes a phase inversion switch and independent level controls. The F-25VM includes the dedicated DN-25VM filter amplifier and FB-25M frequency board, engineered to emulate speaker LC network behavior, and is specifically intended for bi-amping JBL M9500 and Project K2S 9500/S 7500 speakers. A rear-panel switch allows mixing of left/right ultra-low-frequency signals.

Context

The F-25V and F-25VM are part of Accuphase’s professional-grade signal processing lineup, designed for high-end active speaker systems. The F-25V can be upgraded to F-25VM specifications by installing the DN-25VM and FB-25M components. While the F-25V supports up to 4-way operation with additional modules, the F-25VM is optimized for 2-way bi-amp use. Compatible units include LA-25, DN-25, LA-25V, and DN-25V, though panel color and control steps differ, requiring attention when mixing parts.

Market

The original price in February 2001 was ¥390,000 for the F-25V and ¥440,000 for the F-25VM. Optional components included the Line Amplifier Unit LA-25V (¥60,000), Filter Amplifier Unit DN-25V (¥60,000), and frequency boards (¥15,000 each). Converting an F-25V to F-25VM required upgrading the DN-25V circuit (¥20,000) and adding the FB-650M board (¥30,000), sold separately.