Accuphase F-20/F-20M (1997)
A 2-way channel divider released in May 1997, designed for high-precision multi-way speaker systems with modular crossover control.
Overview
The Accuphase F-20 and F-20M are dedicated 2-way channel dividers made for high-fidelity multi-way speaker setups. Released in May 1997, they allow precise frequency separation using interchangeable crossover boards. The F-20M was developed specifically for JBL’s M9500 and Project K2S 9500/S7500 speakers and features a fixed -18dB/oct slope. The F-20 offers switchable slopes of -12dB/oct, -18dB/oct, and -24dB/oct, independent for low and high channels. Both models support balanced and unbalanced connections via rear-panel switching and can be expanded to 3-way operation by adding a second unit.
Specifications
| Type | Channel divider, 2-way dedicated multi-channel divider |
| Production year | May 1997 |
| Original price | F-20: ¥230,000; F-20M: ¥260,000 |
| Weight | 10.4kg |
| Dimensions | 475mm (W) × 150mm (H) × 395mm (D) |
Design
The F-20 uses a balanced input/output circuit with a modular design based on alumina ceramics substrates for superior heat conduction. It features a GIC-type filter circuit with Gaussian characteristics, and crossover frequencies are changed by swapping dedicated frequency boards—common with the F-25 and sold separately. The output stage uses a modular balance circuit with dual feedback amplifiers. Each channel has a phase switch, and the LOW output includes a selector for subwoofer integration. Level adjustment is independent per channel, from 0 to -20dB in fine steps, plus -∞. The F-20M includes a dedicated filter amplifier and FB-650M board, locking the slope at -18dB/oct, and shares the champagne-gold finish and 100% in-house Japanese construction.
Context
The F-20/F-20M follows the technology of the F-25, continuing Accuphase’s no-compromise high-fidelity philosophy. The F-20 can be converted to F-20M specification post-purchase for ¥10,000. Frequency boards are available in 21 standard points from 70Hz to 12.5kHz, including FB-70 (70Hz), FB-100 (100Hz), up to FB-12500 (12.5kHz), with the FB-650M sold separately for ¥30,000.
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