Reference-Derived Valve Musicality & 75-Watt KT120 Power | Available at Trimira Audio
The Audio Research VSi75 SE (Special Edition) is a high-performance vacuum tube integrated amplifier combining Audio Research’s Reference-series circuit heritage with a compact single-chassis design. Handcrafted in Minnesota, USA, this certified trade-in unit delivers 75 Watts per channel through dedicated 4-ohm and 8-ohm output taps.
The VSi75 SE uses four matched KT120 output tubes driven by two 6H30 dual-triode driver tubes, with a passive analogue line stage and a precision 103-step microprocessor-controlled volume attenuator. Reference 75-derived output transformers and coupling capacitors provide wide-bandwidth valve amplification with substantial dynamic capability.
Front-panel tube bias monitoring and an integrated tube-hour meter make ongoing valve maintenance straightforward, while the supplied machined aluminium remote provides convenient system control.
Key Features & Technological Innovations
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Reference 75 Circuit Heritage: Uses wide-bandwidth output transformers and coupling capacitors derived from the Audio Research REF75.
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KT120 & 6H30 Tube Complement: Four matched KT120 output tubes and two 6H30 driver tubes deliver 75 W per channel.
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103-Step Precision Volume Control: Microprocessor-controlled attenuation provides fine volume adjustment across the listening range.
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Tube Bias & Hour Monitoring: Front-panel display provides tube bias information and cumulative operating hours.
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Dedicated 4 Ω & 8 Ω Output Taps: Separate transformer taps allow appropriate loudspeaker impedance matching.
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Substantial Power Supply Storage: Regulated supplies and approximately 350 joules of energy storage provide substantial dynamic reserves.
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Five Analogue Line Inputs: Five single-ended RCA inputs provide straightforward integration with analogue source components.
Technical Specifications
| Specification |
Technical Detail |
| Amplifier Topology |
Vacuum Tube Stereo Integrated Amplifier (Passive Line Stage / Push-Pull Output) |
| Tube Complement |
2 × Matched Pairs KT120 (Power Output), 2 × 6H30 (Driver Stage) |
| Continuous Power Output |
75 Watts per channel continuous (20 Hz – 20 kHz, 1.5% THD at 75W; 0.05% THD at 1W) |
| Power Bandwidth (-3 dB points) |
12 Hz – 70 kHz |
| Frequency Response (-3 dB at 1W) |
1.0 Hz – 70 kHz |
| Input Sensitivity |
0.55V RMS Single-Ended for rated output (32.5 dB gain into 8 Ohms) |
| Input Impedance |
52.5 kOhms Single-Ended |
| Maximum Input |
10V RMS (any input) |
| Output Taps |
8 Ohms, 4 Ohms |
| Output Regulation / Damping Factor |
Approx. 2 dB (8-Ohm load to open circuit) / Damping factor approx. 4 |
| Overall Negative Feedback |
4 dB |
| Slew Rate / Rise Time |
10 V/µs / 4 µs |
| Hum & Noise |
Less than 1.0 mV RMS (-88 dB below rated output, IHF weighted, volume down) |
| Power Supply Energy Storage |
Approximately 350 Joules (with automatic 40-second warm-up mute) |
| Analogue Inputs |
5 × Single-Ended Stereo RCA Line Inputs |
| User Controls & Display |
Volume Up/Down (103 steps), Power, Input, Mute, Bias (front panel & solid aluminium IR remote) |
| Power Consumption |
210W at idle, 400W at rated output, 600W maximum (1.0W standby) |
| Dimensions (W × H × D) |
36.8 cm × 23.5 cm × 41.3 cm (rear connectors extend 2.2 cm beyond chassis) |
| Net Weight |
16.5 kg (36.4 lbs) |
| Finish |
Natural Anodised Aluminium |
Certified Trade-In Assurance at Trimira Audio
The Audio Research VSi75 SE is offered as a certified trade-in unit at Trimira Audio. Pre-owned valve equipment undergoes bench inspection, tube emission and bias testing, and extended acoustic auditioning by our Brisbane technical team.
Contact Trimira Audio to discuss tube hours, cosmetic condition, included accessories, warranty coverage, or to arrange a private demonstration.
