Preamplifier section

The modular design of the SI 1000 makes service maintenance a mere formality. The volume control stage is done in full domain to preserve the quality and integrity of the sound signal. All channels are dual mono design and individual modules are used for left and right channels respectively.

·Individual and separated power supply section
·Class “A” push-pull output stage
·2 pairs of junction FET (J-FET)
·2 pairs of bipolar transistors on the input differential circuit

Power Amplifier section

The SI 1000 uses four bipolar power transmissions for each channel of the power amplifier section. The main circuit is designed to preserve and maintain the maximum quality of sound reproduction and musical integrity.

·Junction FET input
·Proprietary feed-back circuit on the power transmissions for an improved low frequency extension and control
·Push-pull designed parallel output circuit

Main Signal Path

The main signal path uses exclusively discrete components for optimal performance. The use of OP Amps is strictly prohibited at this level!

·DC coupled signal path
·Preamp output for Bi-Amping or Subwoofer application
·Bypass function input for surround processor connection (activated as a 2 channel amp)

The Oracle SI 1000 is equipped with four (4) Unbalanced inputs (RCA) and one Balanced input (XLR). For optimal results we recommend the use of Balanced connections whenever the source component is equipped with a Balanced output.

-Balanced input : Connection for Balanced audio cables between the SI 1000 and the sources material
-Tuner: Connection for tuner, FM / AM broadcasting stations
-Aux.: Connection for video, TV output or any auxiliary devices
-Tape: Connection for a cassette tape deck output for playback
-Rec.: Connection for cassette tape deck input for recording
-Bypass: This input is used for a multi-channel surround processor.

The main left and right outputs of the surround processor are connected to this input. This function is activated when pressing the BYPASS button on the remote control handset or directly on the front panel. The Oracle Audio SI 1000 is then working as a fixed input power amplifier.

BYPASS

The SI 1000 used as Power Amplifier

The Oracle SI 1000 can be activated as a pure power amplifier by pressing the BYPASS button from the remote control handset or directly from the front panel. In this mode, an external preamplifier or surround processor with volume control functionality will be required. To return to normal integrated amplifier mode, just press the BYPASS button again.

Surround Processor connection

To make this connection configuration possible the surround processor should have its own volume control. The volume control should be done at the surround processor side. Because the output from the surround processor is connected to the Oracle Audio SI 1000 BYPASS connectors the pre-out becomes automatically connected to the bypass input. You can take advantage of the multi-amplifier application feature by connecting an external power amplifier to the PRE-OUT connectors.

Using the SI 1000 as a Preamplifier

Connection to an external power amplifier
Disconnect the loudspeaker cables from the amplifier or just press the SPK OFF button on the remote control handset. Connect the PRE-OUT of the SI 1000 to the MAIN IN of the external power amplifier.

Using a self powered subwoofer system

This option will be useful when using a small or medium size loudspeaker system as the main loudspeakers and using the PRE-OUT to connect to a self powered subwoofer for an improved bass extension. Install an interconnect cable between cable between the PRE OUT of the Oracle SI 1000 and the MAIN IN of the subwoofer controller / amplifier. The functions of volume, cut off frequency, phase, etc. should be calibrated directly from the subwoofer controller / amplifier panel. Please refer to the subwoofer owner’s manual for operation.