Accuphase DF-65 Digital Frequency Dividing Network
The Digital Frequency Dividing Network DF-65 harnesses the very best of digital technology in every aspect, including a high-speed 40-bit floating point DSP. The standard unit configuration supports signal processing for up to four-way systems. Highly accurate digital filters offer a choice of 59 cutoff frequency points and up to 96 dB/octave attenuation. Integrated time alignment function adjustable in 0.5-cm steps, and delay compensator for automatically offsetting any filter circuit delays. Monophonic output mode provides high versatility for various configurations.
High-speed, high-precision DSP implements fully digital signal processing Designed to serve as the core component of a multi-amped system, the channel divider DF-65 features high-speed digital signal processing with amazing power. Latest digital circuit topology and advanced technology come together in a floating-point DSP that has a 32-bit mantissa and 8-bit exponent section, serving as digital filter. The division into mantissa and exponent prevents errors even when handling very small values. This results in dramatically improved dynamic range and superior precision, allowing very steep cutoff slope settings of 48 dB or 96 dB per octave. All other functions including phase, delay, and level control are also implemented in the digital domain. The result is ultra-precise filtering free from adverse effects by temperature changes or aging.
Available 59 selectable cutoff frequency points. Filter frequency points can be set over the range from 31.5 Hz to 22.4 kHz in 1/6-octave intervals. In addition, 10, 20, and 290 Hz points are also provided, resulting in a total of 59 points. Each divider unit is fully flexible and allows independent selection of lower and upper cutoff frequency.
Highly accurate 96 dB/oct attenuation slope. The filter attenuation characteristics can be set to 6 dB, 12 dB, 18 dB, 24 dB, 48 dB, or 96 dB per octave. The 96 dB/octave setting in particular allows the driver unit to reproduce only its intended frequency without being affected by adjacent frequency bands. This makes it possible to create a multi-amped system that takes musical accuracy to a wholly new level.
Time alignment function allows delay time setting in 0.5-cm steps. The DF-65 incorporates a DELAY function that uses digital signal processing to electrically adjust the time when the sound from each driver reaches the listener. Normally, a delay would be expressed as a time value, but since the delay here is caused by spatial distance, the DF-65 converts it into a distance value (cm) for display. Delay compensator offsets signal delays in filter circuitry
Further refined MDS++ D/A converter. MDS (Multiple Delta Sigma) is a revolutionary design that employs multiple delta-sigma type D/A converters connected in parallel, for drastically improved performance. In the DF-65, four HyperstreamTM DAC chips (ES9018S made by ESS Technology) of the latest generation are driven in parallel. Compared to a single converter, this results in an overall performance improvement by a factor of 2 (= √4).
- Standard configuration allows 4-channel (4-way) system setup.
- Selectable monophonic output mode for further enhanced specifications.
- Digital attenuator with setting range from – 40.0 dB to +12.0 dB (in 0.1dB steps) allows precise level adjustments for left and right channels.
- "Analog ATT" function can be activated for specific channels to reduce residual noise when using high-efficiency speaker units (ON: –10 dB).
- Versatile choice of input connectors: Coaxial, optical, and /HS-LINK for digital signals Line and balanced for analog signals
- "Full Level Output Protection" function safeguards the speakers if a digital signal without volume control data is input (Output level is reduced to –40 dB). Unused divider units can be set to OFF (all display elements and LED indicators are out).
- Independent phase switching for left and right channel (4 patterns).
- Memory feature allows saving and recalling function settings.
- System backup function allows returning the entire system to a previous condition.
- Safety Lock prevents inadvertently changing any settings.
- Display indication can show predefined strings or custom strings entered by the user (max. 8 charac- ters, character set 97 characters).
- Elegant side panels with natural wood grain finish.