LAB12 Integre4 Mk2 Toroid Integrated Tube Amplifier at Vinyl Sound Buffalo NY

The Integre4 Mk2 Toroid is a push-pull integrated tube amplifier from LAB12 (Athens, Greece), available at Vinyl Sound in Buffalo, NY. Handcrafted by Stratos Vichos and his team since 2012, this flagship integrated delivers 65 watts per channel from a quad of KT150 power pentodes in a true dual mono architecture, spanning a frequency response of 15 Hz to 70 kHz. The Integre4 Mk2 Toroid has earned the Editor's Choice Award from Hifi Pig Magazine and the Best Buy Award from Haute Fidélité, cementing its reputation as one of the most versatile and musically engaging tube integrateds available today.

Dual Toroidal Power and True Dual Mono Architecture

The defining upgrade of the Mk2 Toroid is its pair of independent toroidal power transformers, one per channel, delivering a level of channel isolation and instantaneous current delivery that is rare at this price point. Combined with the upgraded output transformers and a noise-reduction chassis, the dual mono layout ensures that each channel operates completely independently from power inlet to speaker terminal. This architecture eliminates crosstalk at the source rather than compensating for it downstream, contributing to the amplifier's wide, precisely defined stereo image. The LAB12 SRSG (Separate Rails Separate Grounds) implementation further reinforces this by routing signal and power grounds through entirely distinct pathways, lowering the noise floor and allowing low-level detail to surface naturally in the music.

KT150 Power, No-Feedback Topology, and Intelligent Bias

The Integre4 Mk2 Toroid ships with four KT150 power pentodes, a tube known for its combination of power, linearity, and dynamic headroom. The no-feedback topology preserves the natural transient character of the music without the phase-related artifacts that global feedback can introduce, while the Fine Symmetry circuit layout maintains matched performance between channels. Tube rolling is fully supported, with compatibility extended to EL34, 6550, KT88, and KT120. The intelligent bias and protection system, monitored via a large OLED display, automates the bias-setting process and safeguards the output stage continuously. Input flexibility is comprehensive, with five unbalanced RCA inputs and one XLR input, while a built-in tube-driven headphone amplifier and a Blue Velvet ALPS motorized volume control with full remote operation round out an exceptionally practical feature set.

Key Features

• KT150 Output Tubes (quad): Factory-installed KT150 power pentodes deliver 65 watts per channel in a push-pull Class AB configuration; compatible with EL34, 6550, KT88, and KT120 for tube rolling.
• True Dual Mono Design: Dual toroidal power transformers, one per channel, provide complete channel independence from power supply through to output stage.
• SRSG Grounding: LAB12's Separate Rails Separate Grounds implementation routes power and signal paths through distinct ground planes, minimizing noise ingress.
• Fine Symmetry Layout: Precision circuit geometry ensures matched component performance between channels for accurate imaging and tonal balance.
• No-Feedback Topology: Zero global negative feedback preserves the natural dynamics and transient response of the music.
• Built-in Tube Headphone Amplifier: A dedicated tube-driven headphone output is integrated into the chassis, enabling private listening without a separate component.
• Intelligent Bias and Protection System: Automated bias monitoring with real-time OLED display readout protects the output stage and simplifies tube maintenance.
• Blue Velvet ALPS Motorized Volume: Audio-grade Alps potentiometer with motorized tracking and full remote control for convenient operation.
• Comprehensive Inputs: Five RCA inputs and one XLR input accommodate a wide range of analog sources in a single chassis.
• Precision 5mm Aluminum Panel: CNC-machined face panel in Matte Black or Frozen Silver with a glass-blasted anodized finish and five-year manufacturer guarantee.

Technical Specifications

Awards and Critical Recognition

• Editor's Choice Award – Hifi Pig Magazine
• Best Buy Award – Haute Fidélité
• Best Value of 2022 – Part-Time Audiophile

Frequently Asked Questions

What is the LAB12 Integre4 Mk2 Toroid?

The LAB12 Integre4 Mk2 Toroid is a push-pull integrated tube amplifier from Athens, Greece, delivering 65 watts per channel from four KT150 output pentodes in a true dual mono chassis with dual toroidal power transformers. It includes five RCA inputs, one XLR input, a built-in tube headphone amplifier, OLED bias display, remote control, and compatibility with EL34, 6550, KT88, KT120, and KT150 tubes, making it one of the most fully featured and powerful tube integrateds available at its price point.

How does the Integre4 Mk2 Toroid compare to the PrimaLuna EVO 400?

The LAB12 Integre4 Mk2 Toroid and the PrimaLuna EVO 400 are both serious KT150-capable push-pull tube integrateds, but they approach the design philosophy differently. The Integre4 Mk2 Toroid uses a no-feedback topology, dual toroidal transformers in a true dual mono layout, and an integrated tube headphone amplifier, priorities that favor channel purity and a maximally natural sound. The PrimaLuna EVO 400 offers adaptive auto-bias, a broader power tube compatibility list out of the box, and an option for ultralinear or triode operation switching, which appeals to listeners who want to toggle between presentation modes. The LAB12 is narrower in operational modes but achieves its single operating point with a more rigorous power supply architecture.

Can the Integre4 Mk2 Toroid drive low-sensitivity speakers?

Yes. With 65 watts per channel from KT150 output tubes, the Integre4 Mk2 Toroid is one of the most powerful push-pull tube integrateds in its class and is well suited to driving loudspeakers with sensitivity ratings in the 86 to 90 dB range. LAB12 specifies a recommended speaker load of 4 to 8 ohms, and the robust power supply architecture, including dual toroidal transformers and high-capacity reservoir capacitors, provides the instantaneous current headroom needed for challenging loads. Listeners pairing the amplifier with more demanding speakers such as the Dynaudio Evoke 50 or Wharfedale Linton 85 Anniversary have reported fully satisfying results.

What is SRSG grounding and why does it matter?

SRSG stands for Separate Rails Separate Grounds, a proprietary LAB12 implementation in which the signal ground path and the power supply ground path are kept physically and electrically distinct throughout the circuit. In conventional amplifier designs, shared ground planes can allow noise and ripple from the power supply stage to couple into the signal path, raising the noise floor and reducing low-level resolution. By separating these paths completely, the Integre4 Mk2 Toroid maintains a quieter background, allowing subtle musical details, particularly in the midrange and high frequencies, to emerge without masking from power supply artifacts.

Which tubes can I use in the Integre4 Mk2 Toroid?

The Integre4 Mk2 Toroid ships with four KT150 power pentodes and four 6N1P dual triodes for the preamplifier and phase-splitter stages. The power tube complement is compatible with EL34, 6550, KT88, KT120, and KT150 tubes, giving the owner a wide range of sonic flavors to explore through tube rolling. The intelligent bias and protection system with OLED display makes bias adjustment straightforward after a tube change, removing one of the traditional barriers to tube rolling for less experienced users.

Does the Integre4 Mk2 Toroid have a headphone output?

Yes. The Integre4 Mk2 Toroid includes a built-in tube-driven headphone amplifier, making it a true all-in-one solution for both speaker-based and headphone listening. This is a genuine tube headphone stage rather than a passive tap from the output transformer, which means it benefits from the same circuit topology and SRSG grounding that defines the amplifier's performance character. Most standard and high-impedance dynamic headphones are compatible with this output.

Where can I buy the LAB12 Integre4 Mk2 Toroid in Buffalo, NY?

The LAB12 Integre4 Mk2 Toroid is available at Vinyl Sound in Buffalo, NY, an authorized LAB12 dealer serving audiophiles across Western New York and the broader USA. Vinyl Sound carries the full LAB12 lineup and can assist with system matching, in-store demonstrations, and ordering in your preferred finish, Matte Black or Frozen Silver.