Audio Research SP-8 All Tube Analog Preamp with Phono Stage

Description

WHO WE ARE
SkyFi Audio is a small startup business specializing in the purchase, reconditioning, and reselling of high end audio equipment. We only buy equipment that we admire and are passionate about. No mid-fi, no gimmicks, no junk.
Each piece of equipment is cosmetically restored and fully tested in our well-equipped lab by an engineer with 30+ years of experience in the HiFi world. If it does not meet or exceed the original manufactures specifications, it will not be sold. We are very selective about the equipment we purchase, focusing on mostly analog, high-build quality, American, and European built units.
Through our sister company, which is an authorized dealer for McIntosh, Audio Research, Sonus Faber, ClearAudio, Project, and Sony ES, we have access to OEM parts, service, and support.
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One of our best selling preamps from Audio Research. Full featured and capable of working with your turntable.
This example was also factory upgraded to REV6
In overall very good cosmetic condition showing very little signs of wear.
Also comes to you in it's rare original packing!
Specifications:
FREQUENCY RESPONSE
High level section: ±.25dB, 5Hz to 30kHz. -3dB points below 1Hz and above 100kHz. Magnetic phono: ±.25dB of RIAA, 30Hz to 40kHz
DISTORTION (THD)
Harmonic distortion: Less than .01% at 2V RMS output, 20Hz to 20kHz (Typically less than .0005% in midband). Intermodulation distortion: Less than .002% at 2V RMS output
NOISE & HUM
High level: (1) 250µV RMS maximum residual unweighted wideband noise at main output with gain control minimum (86dB below 5V RMS output) (2) More than 90dB below 1V RMS input (less than 20µV equivalent input noise). Magnetic phono: 5µV equivalent input noise, wideband RMS (-66dB reference 10mV input) (Approximately 1µV above 200Hz or -80dB reference 10mV input)
GAIN
Magnetic phono input to tape output: 34dB. Magnetic phono input to main output: 60dB. High level inputs to tape output: 0dB. High level inputs to main output: 26dB.
INPUT IMPEDANCE
50K ohms, all inputs (Magnetic phono may have any value from 10 ohms to 100K ohms substituted. Also has provision to add to the 40pF input capacitance for matching certain magnetic cartridges.)
OUTPUT IMPEDANCE
1000 ohms main output and tape output. Recommended minimum load for maximum audio quality 20K ohms and .001µF maximum capacitance.
OUTPUT POLARITY
-
MAXIMUM INPUTS
Magnetic phono, 900mV at 1kHz. (3.5V RMS, 10kHz) High level inputs essentially overload-proof.
RATED OUTPUTS
2V RMS 5Hz to 30kHz, all outputs; 60K ohm load (main output capability is 60V RMS output at ½% THD at 1kHz into 100K ohm load with 3V RMS high level input)
POWER SUPPLIES
Electronically-regulated supplies utilizing both vacuum tube and solid state elements. Line regulation better than .01%
TUBE COMPLEMENT
SP-8 MKI: (2) 12AX7, (3) 12AX7, (2) 6922, (1) 12BH7. SP-8 MKII: (2) 12AX7, (2) 12AX7, (2) 6922, (1) 12AT7, (1) 12BH7
POWER REQUIREMENTS
100-125VAC 60Hz (190-240VAC 50Hz) 60 Watts
DIMENSIONS
19" (48 cm) W x 5¼" (13.4 cm) H (standard rack panel) x 10¼" (26 cm) D. Handles extend 1 ⅝" (4.1 cm) forward of front panel. Rear chassis fittings extend ⅞" (2.3 cm).
WEIGHT
22 lbs. (10 kg) Net: 30 lbs. (13.75 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.
Item
Included
Original Box
Yes!
Manual
Online
Remote
Not Applicable
Cables
Yes - Power
Physical Condition
8
Working Condition
10
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PURCHASING FROM SKYFI:
This item will be professionally packaged and insured for safe transit to your home unless you opt for local pickup from our shop. Please note that all local pickup items are only wrapped with industrial strength clear cling stretch wrap if the original manufacturer packaging is unavailable.
Local pickup is available in Glen Rock, NJ, just a half hour drive from Midtown Manhattan, with convenient parking near our building.
If we don’t have the original manufacture’s packaging, we use heavy duty double-ply corrugated boxes with custom made to your item Instapak expanding foam custom inserts. In many cases this has proven to be better than the original packaging! We also use high quality fiber reinforced tape to seal our packages. Lightweight items will be bubble wrapped and shipped in a high-quality box.
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PURCHASING GUIDELINES:
We do not accept or review any offers that do not go through the official eBay system. We have too many items for sale and it’s nearly impossible to keep track of offers outside of the official system. Please don’t message, email, or text any offers.
TRADE IN POLICY:
We accept trade-ins of equal or lesser value under certain conditions. Please visit our website to submit your gear for full consideration. We will only consider high-end equipment from mainstream manufacturers such as McIntosh, Mark Levinson, Audio Research, Krell, etc. and will typically pass on displays, projectors, receivers, dated surround processors, and mid-fi equipment of any type. We will offer a fair value for your equipment, but keep in mind we’re running a business and will need to be able to resell the equipment at a profit after investing a great deal of time and resources in testing, certifying, repairing, cleaning, and packaging the incoming equipment. If you’re looking for top dollar, we suggest selling direct on your own.
SELL US YOUR GEAR (Working or Broken):
We’ll also purchase your used or broken gear and arrange pickup if you’re in our local market. Simply visit our website to submit your gear for full consideration.
SCHEDULING AN APPOINTMENT:
We are currently operating from our shop inside our dedicated building in Glen Rock, NJ. You’re welcome to make an appointment if there’s a piece of equipment you’d like to see in operation before or after purchase. We have several well-equipped and dedicated listening areas, plus a dedicated listening studio with tons of equipment of all makes and models. We’re not a store, so please don’t make an appointment if you’re just curious as to how a speaker or piece of equipment sounds. In essence - no tire kickers please.
You can message us here on eBay with any questions or to schedule an appointment. We can also arrange to install, calibrate, and tune your newly purchased gear in your listening room if you’re local to our area. This is super useful when purchasing large speakers or heavy amplifiers. It’s also great for ensuring your new turntable is setup correctly in its final resting place.
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