Audio Research Reference 3 - REF3 - All Tube Line Preamplifier
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.
The home theater bypass inputs allow the connection of an external home theater processor, bypassing the REF 3 volume control and allowing Unity Gain passthrough.
The (4) 6H30π Tubes in the line stage have been replaced with a fresh set of Sovtek tubes. Proper channel balance with both RCA and XLR inputs and outputs was confirmed. The tube time/hour counter was reset to 0 to match the fresh tube installation.
Phono Note: The Phono input is a regular line level input only, requiring the the use of an external phono preamp.
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.
+0 -3dB 0.2Hz to 200kHz at rated output. (BALANCED, 200k ohms load.)
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.)
Main output (SE or BAL input): 11.6dB Balanced output, 5.6dB Single Ended output.
Tape output: 0dB.
(Processor input: 0dB Balanced.)
120K ohms Balanced, 300K ohms SE
600 ohms Balanced, 300 ohms SE main (2), 20K ohms minimum load and 2000pF maximum capacitance.
20V RMS maximum Balanced, (10V RMS SE).
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).
Electronically regulated low and high voltage supplies. Automatic 40 sec. warm-up/brown-out mute.
Line regulation better than .01%.
(4) 6H30P plus (1 each) 6L6GC and 6H30P in power supply.
100-135VAC 60Hz (200-270VAC 50/60Hz) 125 watts.
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.
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.
29.6 lbs. (13.5 kg) Net; 43 lbs. (19.5 kg) Shipping.
The SkyFi Testing Process for Preamplifiers:
We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and transistors are checked for signs of stress or damage. Special attention is paid to the power supply which is the most common source of failure for preamps. We then power up the unit and run a simple 1k sine wave while monitoring the low voltage output on an oscilloscope for signs of distortion or noise to get a baseline.
At this point we will lubricate and clean all switches and potentiometers (that are not sealed) with a high quality contact cleaner, and then re-test all functions for any signs of noise or scratching.
Final testing involves putting actual music through the preamplifier. We have learned over time that some issues are only noticeable to a trained ear while listening to a familiar source material. Our test bench has reference vintage KEF speakers that we are super familiar with which will quickly reveal any discrepancies. Some preamps will then move into the listening room where they will be tested with our in-house reference system.
Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.
Yes - Printed copy from ARC PDF
Yes - Power