Triangle Art I-20 Single Ended Integrated boasts a time-proven circuit configuration, elegant topologies, and powering schemes dating back to the golden age of Hi-Fi. Meticulously designed, it features a heavy-duty chassis, fine electronic components, and high-quality silver wiring, 2.5mm thick PCB with 4oz solid copper plate circuit board for optimal signal flow.

With the I-20 Single Ended Integrated design featuring a high plate voltage, high screen voltage acceleration, lower electron cloud density, and lower cathode current it achieves 80% greater power output efficiency compared to the old standard Class A Triodes. This design allows the signal’s amplitude to undergo velocity modulation rather than simply adding and subtracting with a constant current signal as utilized in standard Class A. The design also allows for increased sensitivity and requires minimal drive current, with one EL34 tube capable of producing up to 20 watts with one section of 12ax7 running less than 1ma of current through it and 35ma with 650v on the EL34 plate. Equipped with Mundroft capacitors, AMRG and Vishay resistors, Elma volume control, and input selector, it offers 4 inputs. 2 pairs of RCA and 2 pairs of XLR.

Design Features

– single-ended type – integrated amplifier
– zero global feedback design
– Pentodes indirectly heated cathodes output type
– short signal path
– full dual mono construction
– 20W of pure class A
– output section – EL34 tube
– driver section – 12AX7 Tube and 12AU7 Line-stage
– hand coiled balanced output transformer
– hand assembled all modulated chassis
– Rhodium plated PTFE insulated RCA input connector
– extensively used computer numeric control machines (CNC)
– 1” (25.4mm) thick aluminum front panel

• Spec:
• Power Max:                   20 watts @ 5% distortion                                                              10 watts @2% distortion
• Frequency Response:   20Hz – 20kHz
• Gain:                              40dB
• Sensitivity:                      200mV for full power                                                                     30mV for 1W
• Rise time:                       13uS
• Noise and Hum:              25uV RMS input referred
• Distortion:                       THD+N: 0.58% at 1W                                                                    IMD: 2.5% at 1W
• Electron Tube:                 2 x EL34, 2 x 12AX7, 2 x 12AU7      Operating Voltage:          115V/230V/50-60Hz
• Power Consumption:       Idle 92W (0.8A at 115VAC)                                                            Max 115W (1A at 115VAC)
• Dimensions:                    16” x 14” x 11” H
• Weight:                            70 lbs without wooden crate

TriangleArt I-20 Single-Ended Integrated Amplifier Review Taking the single-ended triode to a new realm. Review By Paul Schumann (enjoythemusic.com)