Audio Research
Reference 5 SE.
The Audio Research Reference 5 SE brings capacitor and power-supply developments from the Reference Anniversary into an updated Reference 5 chassis, retaining a balanced valve line stage with revised controls and extensive analogue connections.
The Audio Research Reference 5 SE is a stereo valve line-stage preamplifier, hand-built at the company’s Minnesota facility. It updates the original Reference 5 with component technologies drawn from the Reference Anniversary model. The SE designation identifies specific internal and front-panel changes, while the circuit retains a fully balanced Class A triode audio stage.
The SE changes
The Anniversary connection is reflected in the power-supply and capacitor arrangements. Audio Research’s SE announcement describes an extra capacitor board that almost doubles the energy storage of the original Reference 5. It also identifies new and additional Teflon and hybrid coupling and bypass capacitors, together with revised wiring, as parts of the update.
Round metal buttons replace the original Reference 5’s square black controls. The front rotary controls adjust volume and select the source, while the remote also handles balance, the tube-hour display and display brightness. Natural and black faceplate finishes are listed, retaining the manufacturer’s traditional panel arrangement with revised controls.
Audio circuit and power supply
The audio circuit uses four 6H30P dual triodes and operates with zero feedback. A separate 6H30P and 6550C serve the power supply, giving the six valves two different circuit roles. The manufacturer’s component description distinguishes the audio valves from supply regulation, rather than assigning every valve in the chassis to signal amplification.
The brochure places the power transformers off the circuit boards at the sides of the chassis. It lists electronically regulated low- and high-voltage supplies. Together with the additional capacitor board, these are visible elements of the SE’s internal construction; the original specification does not require an external power-supply chassis.
Inputs, gain and system control
Six selectable line sources are provided in XLR and RCA formats, with the balanced or single-ended choice memorised for each input. The connector labelled PHONO is a line-level source input: a turntable requires a separate phono stage before it reaches this preamplifier. The label does not indicate built-in cartridge amplification or RIAA equalisation.
Volume adjustment has 104 steps, numbered 0–103. Main-output gain is 12 dB balanced or 6 dB single-ended. A separate processor input operates at unity gain, passing volume-control responsibility to an external home-cinema processor. The display reads NA in that mode because the preamplifier’s normal level adjustment is bypassed.
The rear panel provides two main output pairs and a record output, with balanced and single-ended connections. Main-output impedance is specified as 600 Ω balanced or 300 Ω single-ended. Audio Research calls for at least a 20 kΩ connected load and no more than 2,000 pF capacitance, setting specific conditions for the connection to a power amplifier.
An automatic muting cycle lasts approximately 40 seconds after switch-on. The manual also describes muting during mains interruptions or severe voltage drops, with the startup timer restarting when normal conditions return. This is a defined power-control function alongside the user-operated mute button, rather than an adjustment to the audio gain or volume-step count.
Published measurement conditions
The manufacturer’s manual specifies a 0.5 Hz–200 kHz response at +0/−3 dB, measured at rated output into a 200 kΩ balanced load. Distortion is listed below 0.01% at 2 V RMS balanced output. The noise specification retains its IHF weighting and level reference: 1.7 µV RMS equivalent input noise at volume setting 1, stated as 109 dB below 2 V RMS output.
Dimensions and consumption
Dimensions are 178 × 480 × 394 mm in height, width and depth, excluding the handles, which extend 38 mm forward. Net weight is 13.9 kg. The brochure gives mains consumption as 130 W in operation and 2 W in standby; those figures describe the preamplifier’s electrical consumption, rather than a loudspeaker-power output rating.
Specifications
| Specification | Details |
|---|---|
| Type / class | Stereo valve line-stage preamplifier; fully balanced Class A triode audio circuit, zero feedback |
| Gain | 12 dB balanced; 6 dB single-ended; processor input unity gain |
| Inputs | Six line inputs plus processor input, XLR and RCA; PHONO-labelled input requires an external phono stage |
| Outputs | Two main output pairs and one record output, XLR and RCA; main output impedance 600 Ω balanced / 300 Ω single-ended; minimum load 20 kΩ, maximum capacitance 2,000 pF |
| Frequency response | 0.5 Hz–200 kHz, +0/−3 dB at rated output into 200 kΩ balanced load (manufacturer manual/brochure) |
| Signal-to-noise ratio | 1.7 µV RMS residual IHF-weighted balanced equivalent input noise, volume at 1; 109 dB below 2 V RMS output |
| THD (distortion) | Less than 0.01% at 2 V RMS balanced output |
| Input impedance / sensitivity | 120 kΩ balanced; 60 kΩ single-ended (manufacturer manual/brochure). Maximum input 20 V RMS balanced / 10 V RMS single-ended. |
| Valves | 4 × 6H30P audio valves; 1 × 6H30P and 1 × 6550C in the power supply |
| Volume control | 104 steps |
| Dimensions (H × W × D) | 178 × 480 × 394 mm, excluding handles; handles extend 38 mm forward |
| Weight | 13.9 kg net |