Audio Research Reference 3 (REF3) All Tube Line Preamplifier

General:
This is a reference series all tube preamp from ARC. 

Loaded with tons of features and featuring that unique and desirable signature ARC tube sound. 

$10,000 MSRP.

The home theater bypass inputs allow the connection of an external home theater processor, bypassing the REF3 volume control and allowing Unity Gain passthrough. 

Tube Notes:
It appears as though the tubes installed in this unit are the original set from the factory. The tube counter on the front display shows only 58 Hours. All tubes test as if they were just pulled out of the box.  

Cosmetic Notes:

• One side panel has light scratching.
  
• The Phono input is a regular line level input only, requiring the the use of an external phono preamp. 
  
• Includes a factory fresh ARC remote control (see photos), manual, and power cord.

More from Audio Research:
"Breakthrough" is an overused term, but it is the most fitting word to describe the REF3. As you can probably imagine, it is difficult to write about a new product like this without sounding clichéd, but the REF3 is so good that it is startling when you hear it in your system. How is its presentation superior to the great products that have preceded it? Simply, in every way. The REF3 is more musically transparent. It presents an immense soundstage that makes everything else sound one-dimensional. Voices and instruments have real body and weight, with pinpoint focus. The deep, powerful bass is fast, articulate, and controlled. It possesses a dynamic swing that is breathtaking. And, most importantly, there is a directness and immediacy that connects the listener with the performance. The results are simply thrilling.

Externally the same dimensions as its predecessors, the REF3 is new inside and out. The front panel marries the classic Audio Research look with a modern display and intuitive controls that will be appreciated. In the middle of the panel is a large display which can show the volume level (numerically and via line graph), input, and operating status (including BAL/SE, Mute, Mono, and Phase). Flanking the display are two knobs which control volume and input. Under the display are four soft touch switches controlling Power, Processor input, BAL/SE, and Mute. The remote controls all front panel functions plus the balance control, and also a display readout of the number of operating hours the vacuum tubes have been in service! It will be easy to integrate the REF3 with system controllers from companies like Crestron or AMX. Inputs are direct access, and there are discreet codes for power on/off, processor on/off, etc.

The rear panel is the same as the REF2 except for the deletion of the tape monitor input. The REF3 does not have the ability to listen to one source while taping another. Also, the IEC connector for the removable power cord has changed from 15A to 20A.

The remarkable level of performance has been achieved with all new audio and power supply circuits. There are four new circuit boards and two new transformers. The new audio circuit is pure tube, Class-A, with zero feedback, utilizing a total of four long-life 6H30 twin triodes. FETs are used for constant-current sources (outside the single path), and the analog circutry uses a long-tailed pair input stage to provide the same performance in either single-ended or balanced operation. Total gain is 12dB balanced, 6dB single-ended. The hybrid power supply has over 50% greater energy storage that its predecessors, greatly contributing to its tremendous dynamic capability. There are other improvements which can be seen on the bench and appreciated in the listening room. Bandwidth has increased from 60kHz to 200kHz; noise has been reduced by 12dB; headroom is much higher, with the maximum input increased to 20V balanced, and distortion has been lowered by 40%. The advancements of the REF3 are both audible and measurable. As you would expect, older REF preamps cannot be updated to the REF3.

It will be easy to hear and see how the REF3 extends the boundaries of preamplifier design. With its great build quality, versatility and the ability to musically transform every system, the REF3 also represents great value. Building upon the foundation of its famed predecessors, the REF3 will be a resounding success.

Brand Background:
Audio Research continues its dedication to unparalleled musical expression and crafting components of the highest quality and lasting value for its customers. Our long-term dedication to service is peerless in this industry (Audio Research, with few exceptions, can repair anything ever produced during its entire history). We continue to seek out new and exciting ways to make music more real and more enjoyable. More than just a name or a marketing tool, Audio Research has come to represent exceptional performance and long-term value. Experience Audio Research – experience High Definition®.

Ownership:
Single Owner

Connections:
Inputs (7): CD, TUNER, VIDEO, PHONO, AUX1, AUX2, PROCESSOR. (XLR and RCA connectors).
Outputs (3): 2 main, 1 tape (XLR and RCA connectors).
Controls: Volume (104 steps), Select Input.
Push Buttons: Power, Proc, BAL/SE, Mute.

General Sound:
Smooth, uncolored, undistorted natural and clean

Cosmetic Condition:
8/10 = Very Good. Excellent front faceplate, one minor flaw on chassis side or top. See our detailed rating description here.

Working Condition:
Working perfectly and tested in our lab and listening room.

Included:
Unit, remote, manual and power cord.

Packing:
Will be packed using our highly developed in-house process and custom packing materials.Specs:
FREQUENCY RESPONSE
+0 -3dB 0.2Hz to 200kHz at rated output. (BALANCED, 200k ohms load.)

DISTORTION (THD)
Less than .01% at 2V RMS Balanced output.

NOISE & HUM
2.7µV RMS residual IHF weighted balanced noise output with volume at 1 (106dB below 2V RMS output.)

GAIN
Main output (SE or BAL input): 11.6dB Balanced output, 5.6dB Single Ended output. 
Tape output: 0dB. 
(Processor input: 0dB Balanced.)

INPUT IMPEDANCE
120K ohms Balanced, 300K ohms SE

OUTPUT IMPEDANCE
600 ohms Balanced, 300 ohms SE main (2), 20K ohms minimum load and 2000pF maximum capacitance.

OUTPUT POLARITY
Non inverting

MAXIMUM INPUTS
20V RMS maximum Balanced, (10V RMS SE).

RATED OUTPUTS
2V RMS (1V RMS SE) into 200K ohm balanced load (maximum balanced output capability is 30V RMS at less than 0.5% THD at 1kHz).

POWER SUPPLIES
Electronically regulated low and high voltage supplies. Automatic 40 sec. warm-up/brown-out mute. 
Line regulation better than .01%.

TUBE COMPLEMENT
(4) 6H30P plus (1 each) 6L6GC and 6H30P in power supply.

POWER REQUIREMENTS
100-135VAC 60Hz (200-270VAC 50/60Hz) 125 watts.

Dimensions:
19" (48 cm) W x 7" (17.8 cm) H (standard panel) x 15½" (39.4 cm) D.
Handles extend 1 ½" (3.8 cm) forward of the front panel.

Weight:
30 lbs.

Link to Manual:
Click Here

Recommended Cables:

Kimber Kable - RCA Interconnects - Better

Kimber Kable - RCA Interconnects - Best

Kimber Kable - BALANCED XLR Connectors - Better

Kimber Kable - BALANCED XLR Connectors - Best

Kimber Kable - Power Cords - Better

Kimber Kable - Power Cords - Best

Testing Process:

We start with a visual inspection of all internal components to make sure that there are no signs of heat stress or damage. Capacitors are checked for telltale signs of predictive failure including bulging, shrunken wrappers, or physical leakage. We also inspect the PCB’s for discoloration from resistors or transistors that may have been running hot. On vintage units we often spot check select capacitors for value and ESR.

When we first power on a preamplifier we connect its RCA output to a Sencore PA81 Power Analyzer which simulates real world loading conditions and gives us an oscilloscope interface. The first order of business is checking that the volume control works smoothly throughout its entire range with acceptable channel balance. This is accomplished by feeding a 1KHz sine wave into one of the preamp’s line level inputs while monitoring the preamp’s output on an oscilloscope. We then switch to a 1KHz square wave to test the tone controls, loudness function, and filters where applicable. During this step we are watching for equal alteration of the test signal by both channels. This also helps us identify dirty controls that will need treatment. Once the basic line stage functions are verified, we test each input individually. This is especially important for devices that use relays to select their sources. If the preamp is equipped with a phono stage we test that as well. We use an inverse RIAA filter which allows us to feed a reference test signal into the phono input with the proper RIAA equalization and level. A square wave or sine sweep is used to verify that the device’s phono stage is faithfully reproducing the RIAA curve. If the preamp under test has balanced inputs and/or outputs these are tested as well.

We finish up our bench testing with a listening test with our bench amplifier and reference speakers. During this test we check for hum or hiss that may not have shown up in earlier testing. We also check that all of the tone controls and filters perform as expected. If the preamplifier has remote control functions these are also tested. Preamps with tube circuits or complicated power supply topologies are connected at our long term test rig for extended stress testing under real world conditions.