SRL V8 MK4 front view SRL V8 MK4 rear view

This product has been continuously improved for years, always keeping within certain physical limits with the intention of keeping alive the philosophy of the Sunrise Lab in enabling updates from the previous versions to the current one - which reinforces the respect to you, the customer! One of the high points that assures the high quality and performance of it is the complete manual and handmade manufacturing process, done with care so that you have an above average equipment, exactly as it should be a hi end product.

Audio Source Total Isolation: “Distinct Signal Isolation”

The new preamplifier circuit enables complete isolation of the main and ground signals from the selected source, relative to other connected equipment on the rear panel. This type of insulation, found only in a few high grade preamplifiers, allows a superior musical presentation to be achieved by eliminating the grounding cross-talk of other connected sources.

This unique Sunrise Lab system produces a superior image and sound stagewith excellent separation of musical instruments and tonality. Through a sophisticated signal differentiation circuit, grounding is done inside the source of the signal. In addition to this improvement, the system virtually eliminates the effect of the famous ground loops.

The power sources of the audio stages are independent, without feedback and without the use of commercial voltage regulators.

Direct Feed on the Amplification Phase: “Direct Power” e “Direct Signal”

Configured in double-mono, the amplification phase has independent feeds. Signal and current pathways are extremely short. The power supply is on the amplifier's main board attached to a separate heatsink.

The wiring from each audio channel, from the output signal to the speaker terminals have the same length. The current flows directly from the transformer windings through "schottky" type diodes, directly feeding the 60,000 uF capacitors directly to the output transistors.

The total length of the diodes to the output transistors is 95 mm. The course of the audio signal and the input on the amplifier's main board to the output transistors is less than 50 mm.

The amplification circuit operates in AB-regime without feedback on the output transistors. This circuit is completelly symmetrical and complementary. The output stage works in class A regime.

Signal Design:

The SRL V8 MK4 has a power circuit with short stroke and low feedback. Every gain of the signal circuit is performed by a single pair of complementary transistors which, because of the class "A" working regime, allows the amplifier a gain stage with extremely low distortion, absolute stability and negligible phase rotation in a range of response much larger than the audible.

Power Supply:

The SRL V8 MK4 has a powerful toroidal transformer of 700 W of power with the possibility of use in various voltages, compatible with the power distributors in Brazil and with the possibility, when requested, to meet other specific countries.

Its several secondaries make the circuits independent, which greatly improves the performance of the device; even in situations of extreme use, the separation of musical instruments from a continual sound mass is impecable.

Active Protection System without Fuses: "Intelligent Fuseless Protection"

Based on the growing trends of power fuses for hi-end audio, we present a radical proposal: The complete absence of the power fuse. Unlike a "non-fuse", which is a solid conductor tube that replaces the main fuse of the equipment, a non-fused electric circuit eliminates the electrical connections of the fuse contacts and continues to protect the equipment. The elimination of these contacts and the fuse altogether, raises audio quality and eradicates all the colorations and limitations that they end up adding in the equipment's electric power.

The system reliably monitors the power transformer's power supply and other critical points in the circuitry. It is activated only if at least one of the following problems occur:

  • Peak current exceeds established limit;

  • At least one of the power amplifier circuits malfunctions causing a DC peak at the output;

  • Overheating beyond the safety limits in at least one of the amplification channels.

A The protection status is indicated by an intermittent flashing light on the VU panel. When the unit is switched off on its front button (or the power to the trigger input is interrupted) and is reconnected after a few seconds, the system restarts and, in the absence of a more serious problem, it resumes normal operation.


The SRL V8 MK4 is focused on a minimalist and functional design. The chassis is 1.5 mm carbon steel, where it is applied a thick high resistance electrostatic coating and the front panel is 13 mm anodized aluminum. The detail in "V" is in black anodized aluminum or wood.

The VU Meter, with new spelling and color, indicates the maximum power between the two channels. It has a key on the back panel that allows you to change the color of your lighting: Amber, off or blue.

Although extremely heavy, part of the steel chassis has been strategically replaced structurally by the heatsinks of the amplification modules - it is due to this arrangement that the heatsinks protrude out of the chassis, increasing the heat dissipation capacity. Internally, anti-vibration elements are used to prevent the formation of hysteresis loops from the chassis.



  • 3 RCA, 1 XLR

    Input Impedance:

  • 20kΩ (RCA), 20+20kΩ (XLR)


  • 2 set of speaker terminals

    Power Rating:

  • Power rating 8Ω: 120W
  • Power rating 4Ω: 240W

    Frequency Response:

  • 0.15 Hz to 270 KHz (-1dB)

    Total Gain:

  • 40 dB


  • 0.1% at nominal power

    Dynamic Headroom:

  • 1.4 dB

    Damping Factor:

  • 600

    Slew Rate:

  • 40 V/us

    Noise Level:

  • < -112 dB (at half power)


  • 445 x 105 x 332 mm


  • 15 Kg
Copyright © Sunrise Lab 2006-