Stereo Integrity SIQ 125.4 Amplifier: Purity at its Finest

The Stereo Integrity SIQ 125.4 signals the return of true high-fidelity audio engineering to the mobile sound space. Built by audiophiles for audiophiles, this Class A/B amplifier prioritizes signal integrity above all else. Its design features zero filters, zero crossovers, and zero EQ, delivering a full bandwidth signal (5 Hz to 150,000 Hz) that is uncompromisingly pure. This is the foundation for an accurate soundstage and breathtaking sonic detail.

Uncompromised Audiophile Construction

Every component in the SIQ 125.4 was selected for its acoustic performance and durability:

• Output Transistors: Utilizes audiophile-grade TO-3 output transistors for clean, linear power.

• Internal Circuitry: Features UPC4570 op-amps, IRFPO64N power supply transistors, and sand cast resistors.

• Connections: Equipped with premium Tiffany-style RCA connections accepting inputs up to 16 Volts.

• Chassis: Features a thick extruded aluminum chassis with a copper anodized shielded transformer cover to minimize noise, topped with a large plexiglass viewing window.

High Power, Ultra-Low Distortion Performance

The SIQ 125.4 delivers robust power with unmatched fidelity, validated by Audio Precision measurements:

• Rated RMS Power Output (4 Channels): 125W RMS x4 @ 4Ω

• Rated RMS Power Output (2 Channels): 200W RMS x4 @ 2Ω

• Bridged Power: 400W RMS x2 @ 4Ω

• Total Harmonic Distortion (THD): 0.01 % (Exceptional clarity)

• Signal-to-Noise Ratio (SNR): 91 dB

Installation and Specifications

• Purity Control: Features a discrete gain knob per channel for precise level matching.

• Dimensions: Compact size at 16.5 x 8 x 2 Inches.

• Current Draw: Maximum current draw of 98 amps, requiring proper wiring and fusing.

The SIQ 125.4 is the ultimate solution for audiophiles seeking true sound reproduction in their vehicle.

Amplifiers Specifications

Frequency Response Minimum	5 Hz
Frequency Response Maximum	150,000 Hz
Signal-to-Noise Ratio (SNR)	91 dB
Total Harmonic Distortion (THD)	0.01 %
Dimensions (W x H x D)	16.5 x 8 x 2 Inches
Rated RMS power output into all 4 channels at 4 ohm	125 Watts
Rated RMS power output into all 4 channels at 2 ohm	200 Watts
Bridged RMS power into 2 channels at 4 ohm	400 Watts

Power

Idle Current Draw	1.6 amps
Maximum Current Draw	98 amps

 

Connections

RCA Input Maximum

16 Volts