ONKYO Integra P-308

Commentary

This is a control amplifier that is designed for full-scale digital applications, with a focus on simplification and high-purity transmission.

The Direct In / Direct Out concept is thoroughly implemented and a multi-functional yet simple circuit configuration is adopted.
Line-type inputs such as CD inputs are selected with the Input Selector switch and sent directly to the master volume-flat amplifier without passing through muting, balance volume, mode, etc.
The tone control employs a direct tone system that uses only passive elements and part of a volume circuit, eliminating the need for tone amplifiers.
In addition, both the input side and the output side are connected by direct connection with the shortest distance.

Equipped with 8 input selectors and an independent double REC selector for Tape1 only and Tape2 & 3.
There are two outputs, each with a MODE switch, so you can get output for 3D subwoofer or center channel playback.
The Output2 is equipped with independent output attenuators on the left and right sides for simultaneous use of balance volume.

The circuit configuration is a super servo amplifier with twin FET input stage and twin push-pull output stage connected directly to the input. As a material that can obtain a constant voltage of about 2 v with relatively small current, excellent characteristics are achieved by applying LED bias, which is advantageous in terms of temperature coefficient and noise generation.

In order to handle very small input signals, the equalizer amplifier has a double-twin-FET configuration with a thermal stabilizer for the input stage to further reduce noise.

The power supply section uses a satellite power supply for low impedance power supply, and also uses separate windings for each amplifier for exclusive block power supply to eliminate mutual interference.
To eliminate noise from the power supply, a noise separator is installed between the primary and secondary sides of the power transformer to prevent common-mode noise from entering from the primary side. Normal-mode noise is eliminated by a charge noise filter.
In addition, the power transformer, charge noise filter, and rectifying / smoothing block are separated from the amplifier circuit and covered with a shield case. Only the DC line is taken out to supply power to the constant voltage circuit, eliminating electromagnetic interference from the power supply.

A signal-in-phase transformer is used on both input and output sides to eliminate common-mode noise from external sources and to improve separation by eliminating interference between L and R caused by ground lines of pin cords connecting devices.

It uses a direct tone control circuit with a contrabus.

Equipped with cartridge selector of MC2 position and MM2 position.

Model Rating

Type	Preamplifier
Input Sensitivity / Impedance	Phono MC : 160 μ V/100 Ω, 220 Ω Phono MM : 2.5mV/47k Ω, 100k Ω CD, Tuner, Line, Tape play : 150mV/20k Ω
Rated output voltage / impedance	Tape rec : 150mV/560 Ω Output : 1 V, 6 V (maximum) / 160 Ω
Phono maximum allowable input (THD0.05%, 1 kHz)	MC:13mV MM:210mV
Frequency characteristic	MC : 4 Hz ~ 150 kHz + 0.2 -3dB MM : 1.8 Hz ~ 170 kHz + 0.2 -3dB CD, Tuner, Line, Tape : 0.8 hz to 170 khz + 0 to 3 db
Total harmonic distortion rate (20 Hz to 20 kHz 3 v output, Vol-30dB)	MC : not more than 0.003% MM : not more than 0.0008% CD, Tuner, Line, Tape : 0.0005% or less
Intermodulation distortion factor (at rated output)	Not more than 0.003% (SMPTE, 70 Hz : 7 khz = 4 : 1)
Signal-to-noise ratio (IHF-A filter Input short)	MC : 76 dB (320 μ V) MM:90dB(5mV) CD, Tuner, Line, Tpae : 106 dB
Tone Control (Vol-20dB)	Bass : ± 10 dB (20 Hz) Bass Selector Bass:450Hz(Boost/Cut) ContraBass:200Hz(Boost) Treble : ± 8 dB (20 kHz)
Filter	High : 7 kHz, 6dB/oct.
Transient killer operating time	Power on:7sec Power off:100msec
AC outlet	Power switch interlock : 2 systems, total 800W Power switch not linked : 1 system, 200W
Pwer	100 VAC, 50Hz/60Hz
Power consumption	22W (Electrical Appliance and Material Control Law)
External dimensions	Width 465x Height 103x Depth 403 mm
Weight	8.5kg