Accuphase F 5 Brochure

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mecuPLase F-5

ELECTRONIC FREQUENCY DIVIDING NETWORK

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- MdJUPLGSe F'5 -

The Accuphase F-5 is a high quality Electronic Frequency
Dividing Network which accurately divides the audio spectrum
of a program source prior to amplification and permits multia
channel amplification to drive directly multi-way speaker sys-
tems. Such a system has many advantages besides minimal
distortion and maximum power transfer, and is especially
effective when used to drive irregular impedance horn speakers.

An Electronic Frequency Dividing Network thus functions as the
heart of a multi-channel amplification system. It is not an
exaggeration to say that a greater part of such a systems worth
in producing good sound will depend on the quality of the
Frequency Dividing Network that is used.

The Accuphase F-5 Electronic Frequency Dividing Network was
designed and produced specifically for this one function, to do it
best, and most effectively. It is ideal for serving as the heart of
a bi-amplification or tri-amplification application. If desired the
program source can be further divided into four or five audio
passbands by using two F-E units,

To seek the utmost performance, the F6 is designed only to
provide the original functions of a frequency dividng network.

A wide choice of crossover frequency points is available. These
are selectable by plug-in "Crossover Boards contained on
separate printed circuits. This minimizes both left and right
channel interference, as well as interference between audio
passbands. The Operational Amplifier of the active element
utilizes a high gain IC with superior high frequency and S/N
characteristics. All elements were carefully selected to eliminate
any possible coloration or deterioration of sound quality.

I MINIMAL INTER»CHANNEL INTERFERENCE
Even the slightest impurity of signal will be clearly reproduced in
a high quality multi-channel amplification system This makes it
imperative to keep interchannel interference, both the left and
right channel crosstalk, as well as that between the low medium
and high passbands to an absolute minimum. Special importance
was attached to this in terms of circuit design, layout and wiring
for the F-5, with most gratifying results. For instance, crosstalk
between left and right channels for frequencies below 1000 Hz is
abom -100 dB, and it is around ~90 dB for freQUencies above
10 kHz, which compares favorably with the excellent noise level
ratios.

HIGH GAIN AMPLIFIER ASSURES IDEAL
ATTENUATION CHARACTERISTICS
The slopes of an active filter attenuate to a certain level, after
which they reverse its characteristic. This happens when the gain
of the active element has reached its limit and has lost its

effectiveness. To keep this limiting point as low as possible, an
active element with maximum original gain should be utilized.
This is achieved in the F-5 with A-class DC Operational
Amplifier IC, with the resulting high gain of 100 dB, as well as
high S/N and superior transient characteristics.

CROSSOVER FREQUENCY SELECTABLE
WITH PLUG-IN SYSTEM

To assure good channel isolation, the crossover frequency points
are changed by plug-in Crossover Boards, on which are mounted
the required CR elements. Expensive silvered-mica capacitors are
used unsparingly wherever sound quality may be affected, For
this reason the cost of the Crossover Boards differ according to
the crossover frequency point, and these plug-in Boards are sold
separately,

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WIDE CHOICE OF 16 STANDARD

CROSSOVER FREQUENCIES
The following Crossover Boards are available which allow choice
of 16 crossover frequency points, and provide audio passbands
for almost any combination of two to five way applications:
100Hz,180Hz, 250Hz,350Hz, SOOHZ, 650Hz, BDOHZ, 1,200HZ,
1,800Hz, 2,500HZ, 3,500HZ, 5,000HZ, 7,000H2, 8,000HZ,
10,000Hz, 12,500Hz.

SELECTABLE j2dB/Oct or 18dB/Oct
CROSSOVER ATTENUATION
Selection of cut-off attenuation at the crossover freQUency
between the most common lZdB per octave, or the 18dB per
octave, which is suitable for certain horn type speakers, can be
made easily with the Selector Switch that is positioned on the
Crossover Board.

UTILIZATION FOR OTHER THAN 3-WAY
APPLICATION
The F-5 can also be used readily for 2»way application. Merely
use the Bi-Amplification Board that is sold separately, and plug
it into the mid»high frequency corssover socket. Two F-5 units
can be used simultaneously to form a 4 or 5 way amplification.

7 BUILT~IN MID-HIGH LEVEL CONTROL

The level control of the Power Amplifier should be used
normally for controlling the level of that respective channel.
Therefore, a level control each for mid and high has been made
available in the F-5 for level control functions in case the
amplifier that is used has no such provisions.

8 CHOICE OF TWO DESIGNS
This Electronic Frequency Dividng Network is available in two
designs, type F-5A and F58. The F-5A matches the M60 and
P-20 and is suitable for rack mounting. The F-SB is a side plate
type which matches the P-BOO and P-250.

Type A I Mountable on 19 standard rack

Type B 1 Front panel designed to match
P-300/P-250/C-200/T-100