|ONKYO Integra P-309
|250,000yen(around the 1983 time)
The stereo preamplifier developed as a compilation
of "W and the super servo scheme" into which the "super servo scheme" was
The gain up of equalizer amplifier is aimed at so
that man-month type to MC type can respond to all the cartridges, without Onkyo
using head amplifier and a step amplifier transformer taking advantage of the
property of the super servo scheme developed uniquely.
Let three units of MC
head amplifier, an equalizer, and a buffer collectively be the simple equalizer
amplifier of 1 stage scheme,The large-current first class amplifier which is
equal to output 5W class power amplifier is adopted, and the NF-CR splitting
type equalization is realized in one step without buffer amplifier.
first rank differential-amplifier part, the heat joint treatment of two a
super-low-noise and High Gm FET is carried out in an aluminum case, and visitor
thermal noise is suppressed with the thermal balance modification. Moreover, a
differential part is made the Para interconnection and the improvement in S/N is
aimed at by lowering an impedance. In order that this differential amplifier may
stop a mirror feedback capacity, it was made the cascode interconnection and has
aimed at the expansion of the frequency characteristic.
nakedness gain was secured by the 2nd step differential amplifier and the
differential amplifier with the 3rd step current mirror, and the stability and
the constant distortion are realized by using a partial feedback according it to
a skillful pole setups.
The weighting monitor is carried in the panel
This monitor detects the first class push pull transistor of an
equalizer final stage, and the temperature of the transistor currently used for
the power-source part of an equalizer, and shows the stability of the bias after
Power ON, and the operating state of amplifier with the indicator which shines
to five steps.
In order to prevent a part for an inductance, a resisted
part, contact resistance, a crosstalk in a terminal area that an extension cord
has, W and a super servo scheme are adopted.
W and the super servo scheme
which cancels in equivalent the harmful noise component which suppresses the
cross modulation by unnecessary super-low-pass one, and originates in the
impedance between groundings,By using an attached servo sensor code, distance
between a pre and power was electrically made into zero, and the harmful
component is canceled.
The direct tone which is an original tone control
scheme which does not affect a tone quality is adopted.
It consists of only passive elements, and since it is a scheme into which
a capacitor harmful in a signal passage path does not go, a sound field
correction can be performed freely, without affecting a tone quality.
Although the problem of low-pass
running short extremely tended to occur when the low power amplifier of an input
impedance was connected or the parallel drive of two or more power amplifier was
carried out,Since it is not necessary to put a capacitor into an output fraction
by adopting a super servo scheme and a low-pass time constant is determined only
in a servo circuitry, it has prevented shortage occurring in low-pass regardless
of the load intensity.
About the power source, while making the power
source of a right-and-left channel become independent completely and supplying
it, in order to prevent the interference which leads the power source in the
order stage also within the same channel, low-impedance-ization of the whole
power-feeding system is attained and the occurrence of the dynamic modulation
(transitional cross modulation distortion) is suppressed.
while using NF type constant-voltage stable circuitry which achieved the
right-and-left independency, each circuitry block is directly linked with the
plate-mill bus (bus-bar) line made from a copper plate.
According to the
cartridge which carries the cartridge selector and is used, the change of the
optimal load impedance is possible.
Also when not recording by carrying
the recording selector, it is considered so that the deck may not remain always
connected to a part of circuitry.
Moreover, it is also possible to record a
tuner output, hearing a record.
Headphone amplifier is built in so that
a using of headphone can be performed.
Various filters, a muting, an
input selector, etc. are accommodated in a kangaroo pocket.
first, a shielding part uses non-magnetic material, such as copper, aluminum, and a brass, for required component partses altogether, and is suppressing high
order higher-harmonic distortion generated under the influence of magnetic flux
until it results in each part article.
The one-touch selector of an
illuminaned button switch is adopted as the change of an input.
the scheme selected by low-profile special audio relay is adopted, and the
signal system product line is not taken about.
The thermostat coupled
register is carried, and the register who acted as a couple of the heat fator is
used so that the delicate servo effect may always start stably to a signal.
||W super servo scheme stereo preamplifier
||Phono MC: 130 microvolt/100ohm, 330ohm
Phono High Gain MC: 2.5mV/100 ohm
Phono man month: 2.5mV / 47kohm,
Tuner, AUX, Tape Play:150mV /, 47kohm
|An Output voltage/impedance
||Tape Rec: 150mV / 2.2kohm
Output: 1.5V, a maximum of 13V/220ohm
|Phono maximum permissible input (THD 0.05%,
man month, High Gain MC: 380mV
||Phono MC: 4Hz-150kHz+0.2 -3dB
month: 1.8Hz-170kHz+0.2 -3dB
Tuner, AUX, and Tape:0.8Hz-170kHz+0 -3 dB
|THD (THD, 20Hz - 20kHz, output 3V)
||Phono MC (Volume-30dB): 0.008% or less
Phono man month (Volume-30dB): 0.002% or less
Tuner, AUX, Tape: 0.002%
|Cross modulation distortion (SMPTE
||0.003% or less (at the time of an Output
|S/N (an IHF-A network, an input shunt)
AUX, Tape: 100dB
|Tone control (Volume-20dB)
||Bass: 70Hz, ±8dB
Treble: 20kHz, ±8dB
||High Cut Filter: 7kHz, 6dB / oct
Subsonic Filter: 15Hz/20 Hz, 6dB / oct
|Transient killer operating time
|The semiconductor used
||Transistor: 71 pieces
FET: Ten pieces
IC: Eight pieces
Diode: 50 pieces
||Power-source interlock: Two lines
Un-interlocking.: Two lines
Total 1000W (maxima)
|Power consumption (Electrical Appliance and
Material Control Law)
||Width 476x height 122x depth of 415mm