audio research

Tube stereo preamplifier (SP17) / line stage (SP17L).

From the ARC website

The SP17 brings much of the performance offered by its acclaimed and more expensive siblings to a price range that is within reach of many music lovers.

Externally, the SP17 looks virtually identical to its predecessor, the SP16, with a full-sized 19" front panel, handles, and the same display. The SP17 is completely single-ended with five sets of inputs (labeled Phono, CD, Tuner, Video and Aux), plus a Processor (unity-gain) pass-through. There are two sets of Main single-ended outputs, plus a Tape (monitor) out. There is a 12-Volt trigger, full remote control, and a removable 15A IEC power cord.

Internally, much has been improved. The SP17 features low-noise JFET inputs in both the line- and phono-stages, and instead of 12AX7s you will find a 6H30 in each section – all of our preamplifiers now employ this high performance long-life tube. The same high-voltage regulator found in the LS17 and LS26 is now utilized in the SP17, and so is the same 103-step volume control – the SP16's control had only 70 steps; adjustment of the volume is much finer now, which is especially useful at low volume settings. The maximum input is 9 volts RMS, versus a maximum of only 3.5 volts RMS before overload in the SP16. The SP17 features direct access codes and discrete On-Off commands for power and mute functions for incorporation in a system with a master controller. And, like all of our other preamplifiers, the SP17 is pure Class-A. The line-only SP17L is also available without the phono stage installed.

Bandwidth has increased, with -3dB points below 0.3Hz to above 120KHz. Output impedance has been lowered, improving the SP17's ability to drive long cables and low impedance amplifiers. Gain in the line section has been reduced very slightly, from 11.5 to 11.1dB, but it has been increased in the phono section from 43.5dB to 47dB. The SP17 is 2dB quieter in its line section and is 9dB quieter in its phono section, making it an astonishing 11dB quieter overall. Now it is much easier to use a phono cartridge with an output below 1mV without incurring noise.

What do all of these changes translate to musically? Greater articulation, better image focus and an apparent speed resulting from lower distortion and a lack of smearing. Bass definition and control are improved, and dynamics simply pop. And because it is so quiet, the music stands out in bold relief against a black background. Individually, each of these attributes is easily identified and meaningful, but combining them in the SP17 provides one with the same type of magic offered by our costlier line-stages.

We are excited to offer a product with the remarkable musical performance of the SP17. It will infuse new life and vitality into virtually any system and will surely become the next benchmark in its segment of the market.





MSRP (US new retail)
$2,995 (SP17L)
$3,495 (SP17)


Frequency response Line: +0-1dB, 0.6Hz to 80kHz at rated output. -3dB points below 0.3Hz and above 120KHz.
Phono: ±0.3dB of RIAA, 10 Hz to 20KHz
Distortion (THD) Less than .005% at 2V RMS output.
Noise & hum Line: 12µV RMS IHF weighted at main output with volume low (104dB below 2V RMS output).
Phono: 0.3µV RMS IHF weighted equivalent input noise, shorted input (76dB below 2mVRMS 1KHz input).
Gain Main output line: 11.1dB Processor: 0dB.
Phono: 58dB at 1 KHz.
Record output, line: 0dB. Phono: 47dB.
Input impedance 60K ohms line, 47K ohms Phono, (0.7 to 7mV High output cartridge recommended).
Output impedance 210 ohms Single Ended main; 20K ohms minimum load and 1000 pF maximum capacitance. Record output 60K ohms minimum load and 100pf maximum capacitance.
Output polarity Non inverting
Maximum inputs Line: 9V RMS.
Phono: 40mV RMS 1KHz, 100mV RMS 10KHz.
Rated outputs 2V RMS into 100K load. (Maximum output 15V RMS at 1% THD at 1kHz.)
Power supplies Electronically regulated low and high voltage supplies. Automatic 25 sec. warm-up/brown-out mute. Line regulation better than .01%.
Tube complement (2) 6H30 dual triodes
Power requirements 100-135VAC 60Hz (200-270VAC 50/60Hz) 39 watts.
Other Inputs (6): phono, CD, tuner, video, aux, processor. Model SP17L has no phono input.
Outputs (3): 2 main, 1 record (Single Ended RCA connectors).
Push buttons: Volume up, volume down (102 steps, 20 LED indicators), Input, Processor, Mute, Power. All functions on IR remote control.
Dimensions 19.0" (48 cm) W x 5.2" (13.2 cm) H x 10.0"(25.4 cm) D. Rear connectors extend 0.6" (1.5 cm). Front handles are optional.
Weight 12.6 lbs. (5.7 kg) Net; 20 lbs. (9.1 kg) Shipping.