{"title":"Preamplifiers","description":"","products":[{"product_id":"audio-research-sp-15-preamp-sp-15ps","title":"Audio Research SP15 Hybrid Tube Preamplifier w\/External SP15PS Power Supply","description":"\u003cp\u003eHere we have for sale a rare Audio Research SP15 Hybrid Tube Preamp with separate SP15PS Power Supply. It has been a treat to have the SP 15 in our shop, as we have enjoyed listening to this unit. The phono section on this unit is superb.  Physically the units are in good condition. There are some nicks, scratches, some fading of the black anodized aluminum on the control unit. The SP 15  has been detailed and the face plates present themselves well. It has been gone through and tuned up. All potentiometers and switches were cleaned, lubricated, and we replaced two capacitors in the power supply.  A final testing on our workbench showed the unit was functioning as it should. We then ran the unit in one of our house systems for quite some time, because we wanted to utilize this flagship preamp from Audio Research.  It is a difficult unit to part with. We took this unit in with a pair of Audio Research Classic 150 Amps that we finally just went through and installed 16 new Svetlana 6550 tubes in and set the bias. We were partially holding onto this preamp because we wanted to pair it one more time with these amps before we let it go. Just a killer setup. If you are considering this preamp, you can inquire about the 150's if interested. \u003c\/p\u003e\n\u003cp\u003eThe following is an Audio Research SP15 Review by James Leahy.\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eThe Audio Research SP15 was introduced to the world in 1988 and is a full functioning Pre-Amplifier with Inbuilt Phono Stage. As can be seen from the pictures, the SP15 is constructed on Two (2) Chassis, utilizing Aircraft-Quality Connectors and an Interconnect Cable Forty-Eight (48 \") Inches long. The Unit is divided into an Active Amplification Chassis (SP15) And A Power Supply Chassis (SP15PS).\u003cbr\u003e\u003cbr\u003eA Custom Interconnect Cable of longer length is available from Audio Research at additional cost, although some degradation of performance will occur as the Cable lengthens.\u003cbr\u003e\u003cbr\u003eThe Power Supply is in the pictures, as well as the Control Section.\u003cbr\u003e\u003cbr\u003eIf you are a Control Freak, this is the Pre-Amplifier for you. It has a plethora of functions to play with and is the ultimate in flexibility.\u003cbr\u003e\u003cbr\u003eThe Power Supply has Two (2) Controls, One is the Main Power and the other is the Auxiliary Power Outputs for various other components that can be Switched On or Off via the SP15.\u003cbr\u003e\u003cbr\u003eThere is a five level attenuation control that is designed to equalize source levels and give a huge range of volume control to the pre-amplifier. It is graded in 6dB increments and is adjustable down to -24dB.\u003cbr\u003e\u003cbr\u003eThe Volume Control is the usual Analogue Pot with Graduated Positions being used for this Multi-Ganged Heavy Gold Platted Unit designed to minimize Sonic Degradation of Microvolt Level Analogue Signals.\u003cbr\u003e\u003cbr\u003eThere is a Balance Control that is useful in some poor acoustical environments.\u003cbr\u003e\u003cbr\u003eThere is One (1) Pair of Balanced Outputs as well as Two (2) Pairs of Single Ended outputs. As always, I recommend using the Balanced Output to connect up to your Power Amplifier, if it has this available too.\u003cbr\u003e\u003cbr\u003eThe SP15 has Mono, Stereo, Left, Right and Reverse listening modes.\u003cbr\u003e\u003cbr\u003eThe Phono Circuit has impedance settings of 3, 10, 30, 100, and 47 K ohm.\u003cbr\u003e\u003cbr\u003eThere is also a 'Direct' Mode that in the \"Bypass\" position, directly connects the Attenuator to the Output of either the RIAA Compensated Phono Amplification Circuitry or a selected Line-Level Source (such as CD…),\u003cbr\u003e\u003cbr\u003eThe \"Balance\", and \"Mode\" Controls, as well as the \"Monitor\" Switch are removed from the Active Circuit path when this Switch is in operation.\u003cbr\u003e\u003cbr\u003eThe Bypass Switch is provided for use with Audiophile-Quality Program Material or whenever Maximum Fidelity to The Input Signal is desired.\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eThere are Three (3) 6922 Vacuum tubes used in Intermediary Gain Stages in the Phono Section of the SP15.\u003cbr\u003e\u003cbr\u003eEach of the levels of Circuitry Amplification is provided with its own electronic regulation in the form of a \"Capacitance Multiplier,\" providing essentially \"zero\" impedance power supplies with essentially infinite isolation between circuit sections. Thus, the active circuitry is allowed to operate near theoretical performance levels.\u003cbr\u003e\u003cbr\u003eThe separate \"Active\" Chassis contains both the High-Gain, RIAA Equalized, Magnetic Phono Preamplifier and the \"Line\" Level Circuitry, plus all of the Inputs, Outputs and various Function Controls.\u003cbr\u003e\u003cbr\u003eExtensive use has been made of State-Of-The-Art Audio Materials, including such items as Polypropylene And Polystyrene Dielectric Capacitors, Metal Film Resistors, Wire-Wound Resistors, proprietary Point-To-Point Internal Wiring, Gold-Plated Input and Output Connectors, Heavily Gold-Plated Switches, and other high-quality components.\u003cbr\u003e\u003cbr\u003eThe SP15 is The Ultimate Pre-Amplifier even to this day that has an inbuilt Phono Section. The improvements over the much loved but not forgotten SP11 are as follows:\u003cbr\u003e\u003cbr\u003eLike the SP11, the new SP15 is a \"Hybrid\" Preamplifier using both Vacuum Tubes and Semiconductors as gain devices.\u003cbr\u003e\u003cbr\u003eHowever, the SP15 uses only three (3) tubes compared to the SP11's six;\u003cbr\u003e\u003cbr\u003eand whereas the SP11's tubes were employed in both phono and line sections, the SP15's tubes are confined to the Phono Section alone.\u003cbr\u003e\u003cbr\u003eAs in the SP11, these tubes are not required to be selected, low-noise types.\u003cbr\u003e\u003cbr\u003eThe changes in the SP15 line section (as compared to the SP11) are not limited to choice of gain devices. Resistance to input overloads, reduction of inherent noise levels, resistance to inter-input crosstalk and dynamic headroom have all been achieved as a result of circuit redesign in this area.\u003cbr\u003e\u003cbr\u003eConvenience features and controls remain similar to the SP11, but with some significant additions. The familiar \"Gain\" control has been replaced by a 5-position \"Attenuator\" switch having 6dB increments, resulting in better sonics while maintaining a useful selection of settings to match the output characteristics of both phono cartridges and CD players.\u003cbr\u003e\u003cbr\u003eTape and dubbing functions remain identical to the SP11.\u003cbr\u003e\u003cbr\u003eOn the back of the SP15 are new provisions for either Conventional (i.e. Single-Ended) or Balanced Output connection(s). Balanced connections can be made via the RCA jacks labeled \"Direct\" and \"Invert,\" or by using the new industrial \"XLR\" connector provided.\u003cbr\u003e\u003cbr\u003eLike the SP11, the SP15 is a Two (2) Chassis design isolating Power Supply functions from sensitive Preamplifier Circuits, reducing the opportunity for magnetic field effects to degrade sonic performance.\u003cbr\u003e\u003cbr\u003eA Toroid Power Transformer minimizes mechanical buzz and \"hum.\" See Installation Instructions for details on proper placement of the Two (2) chassis relative to one another.\u003cbr\u003e\u003cbr\u003eThe SP15 reflects a further evolution and refinement of the idea that state-of-the-art preamplifier performance can be combined with real-word user convenience and system flexibility.\u003cbr\u003e\u003cbr\u003eCare has been taken to optimize the sonic performance of a variety of popular input options -- video, compact disc, tuner and analogue tape, as well as unsurpassed phono reproduction.\u003cbr\u003e\u003cbr\u003eSonic Evaluations:\u003cbr\u003e\u003cbr\u003eThe SP15 was fired up with Kim Carnes timeless classic Bette Davis Eyes from the 'Mistaken Identity' album (EMI Records, 1981). The soundstage was both wide and deep. I was more than a little impressed with the sonic maturity of this product even by today's standards.\u003cbr\u003e\u003cbr\u003eThe SP15 had an impressive level of drive and slam compared to the LS15 that I reviewed at the same time.\u003cbr\u003e\u003cbr\u003eThe SP15 was in a different class sonically and had a marvelous top end that was not harsh or brittle. The midrange was smooth without any obvious flaws or trouble spots. Bass extension was well defined and quick.\u003cbr\u003e\u003cbr\u003eOn the whole it is a very worthwhile unit with great features that would surpass all in the SP line up that I have heard. Even the latest SP16 that I have tried and did not take to.\u003cbr\u003e\u003cbr\u003eFor all those who wish to know about the quality of the Phono Stage in the SP15, read on.\u003cbr\u003e\u003cbr\u003eThe internal phono stage of the SP15 is the best that I have heard in an integrated component. However this is not saying much.\u003cbr\u003e\u003cbr\u003eI have done extensive comparisons with the SP15 and the separate Audio Research PH5 Phono Stage and the difference in quality is huge.\u003cbr\u003e\u003cbr\u003eAs I would have expected, I was just not prepared for the level of difference that could be heard when I paired up the SP15 with the PH5. It was JAW DROPPING. If you are into your vinyl then the PH5 is a must have as you can by-pass the phono section in the SP15 while still maintaining use of all the other great benefits of this wonderful classic unit.\u003cbr\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eSPECIFICATIONS:\u003c\/p\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eFREQUENCY RESPONSE\u003c\/div\u003e\n\u003cdiv\u003eHigh level input: ±1dB 0.2Hz to 100kHz. -3dB below 0.1Hz and above 200kHz. Phono input: ±.2dB of RIAA 20Hz to 40kHz. ±1dB of RIAA 1.0Hz to 100kHz.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eDISTORTION (THD)\u003c\/div\u003e\n\u003cdiv\u003eHarmonic distortion: Less than .005% at 2V RMS output, 5Hz to 20kHz (Typically less than .001% at midband, phono or line input). Intermodulation distortion: Less than .003% at 2V RMS output\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eNOISE \u0026amp; HUM\u003c\/div\u003e\n\u003cdiv\u003eIHF weighted, shorted input: Output (Gain down): 6µV (110dB below rated output). Input (High level): 3µV equivalent input (110dB below 1V input). Phono: 0.15µV equivalent input (76dB below 1mV input)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eGAIN\u003c\/div\u003e\n\u003cdiv\u003eAt 1kHz, bypass mode: Phono input to tape output: 46dB (0.2V output from 1mV input). Phono input to main output: 75dB (0.175mV input for 1V output). High level input to main output: 29dB (36mV input for 1V output).\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eINPUT IMPEDANCE\u003c\/div\u003e\n\u003cdiv\u003ePhono: Front panel selectable 47K, 100, 30, 10, 3 ohms. Phono input capacitance: 150 pF at 10kHz. High level: 20K ohms or higher, depending on switch functions.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eOUTPUT IMPEDANCE\u003c\/div\u003e\n\u003cdiv\u003e200 ohms main, direct, inverted outputs. 500 ohms tape output. Recommended load 60K-100K ohms and 100pF (20Kohms minimum, 1000pF maximum)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eOUTPUT POLARITY\u003c\/div\u003e\n\u003cdiv\u003eTape outputs, direct output: Non-inverting. Invert output: Inverting. Main outputs (2): Selectable non-inverting or inverting. All outputs may be used simultaneously.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eMAXIMUM INPUTS\u003c\/div\u003e\n\u003cdiv\u003ePhono: 350 mV RMS at 1kHz, 1200 mV RMS at 10kHz (0.1 second maximum duration, 6dB less if continuous). High level: 25V RMS.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eRATED OUTPUTS\u003c\/div\u003e\n\u003cdiv\u003e2V RMS 1Hz to 100kHz main, direct, inverted outputs. (Maximum 80V RMS at 0.2% THD at 1kHz into 60K ohm load with 2.85V RMS high level input).\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003ePOWER SUPPLIES\u003c\/div\u003e\n\u003cdiv\u003e-\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eTUBE COMPLEMENT\u003c\/div\u003e\n\u003cdiv\u003e(3) 6DJ8\/ECC88\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003ePOWER REQUIREMENTS\u003c\/div\u003e\n\u003cdiv\u003e95-135VAC 60Hz, 190-270VAC 50\/60Hz, 130 Watts maximum\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eOTHER\u003c\/div\u003e\n\u003cdiv\u003eFilter: 25Hz Hi-pass phono subsonic 6dB\/octave rolloff (to eliminate ringing) with transition to 12dB\/octave at 10Hz. Front panel switchable phono only. Controls (6): Gain, Attenuator, Balance, Mode, Input, Impedance. Switches (8): Tape monitor, Copy, Tape 1\/2, Tape 1to2 \/ 2to1, Mute, Invert phase, Bypass, Filter.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eDIMENSIONS\u003c\/div\u003e\n\u003cdiv\u003e(Each chassis, EIA Rack panel mounting) 19\" (48 cm) W x 5 ¼\" (13.4 cm) H x 10 ¼\" (26 cm) D. Handles extend 1 ⅝\" (4.1 cm) forward of panel. Interconnect cable extends 4\" behind rear of chassis.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eWEIGHT\u003c\/div\u003e\n\u003cdiv\u003eSP-15: 14 lbs. (6.4 kg) Net, 23 lbs. (10.5 kg) Shipping. SP-15PS: 15 lbs. (6.8 kg) Net, 23 lbs. (10.5 kg) Shipping. Total: 29 lbs. (13.2 kg) Net, 46 lbs. (21.0 kg) Shipping.\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Audio Research","offers":[{"title":"Default Title","offer_id":32104556593257,"sku":"000058","price":2300.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/6FAA6E75-D8B9-43B4-8A77-5DC717BC84F6_1_201_a.heic?v=1735531952"},{"product_id":"audio-research-sp-8-preamp-w-phono-black-faceplate","title":"AUDIO RESEARCH SP-8 PREAMP W\/PHONO BLACK FACEPLATE","description":"\u003cp\u003eWe are offering a fully tested and serviced Audio Research SP-8 Tube Preamplifier. We acquired this preamp along with an AR D60 (For sale as well) also with a black faceplate.  We hooked up the two units in one of our systems for a week and they sounded fantastic, we especially liked the phono stage. Cosmetically the unit is in excellent condition with only a few scuff marks on the back of the top cover.\u003c\/p\u003e\n\u003cp\u003eFrom Audio Research\u003c\/p\u003e\n\u003cdiv class=\"label\"\u003e\n\u003cdiv class=\"label__text\"\u003eSpecifications\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"section__content-wrapper\"\u003e\n\u003cdiv class=\"model-specifications-section__container\"\u003e\n\u003cdiv class=\"model-specifications-section__specifications-wrapper\"\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eFREQUENCY RESPONSE\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003eHigh level section: ±.25dB, 5Hz to 30kHz. -3dB points below 1Hz and above 100kHz. Magnetic phono: ±.25dB of RIAA, 30Hz to 40kHz\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eDISTORTION (THD)\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003eHarmonic 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\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eNOISE \u0026amp; HUM\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003eHigh 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)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eGAIN\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003eMagnetic 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.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eINPUT IMPEDANCE\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003e50K 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.)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eOUTPUT IMPEDANCE\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003e1000 ohms main output and tape output. Recommended minimum load for maximum audio quality 20K ohms and .001µF maximum capacitance.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eOUTPUT POLARITY\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003e-\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eMAXIMUM INPUTS\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003eMagnetic phono, 900mV at 1kHz. (3.5V RMS, 10kHz) High level inputs essentially overload-proof.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eRATED OUTPUTS\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003e2V 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)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003ePOWER SUPPLIES\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003eElectronically-regulated supplies utilizing both vacuum tube and solid state elements. Line regulation better than .01%\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eTUBE COMPLEMENT\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003eSP-8 MKI: (2) 12AX7, (3) 12AX7, (2) 6922, (1) 12BH7. SP-8 MKII: (2) 12AX7, (2) 12AX7, (2) 6922, (1) 12AT7, (1) 12BH7\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003ePOWER REQUIREMENTS\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003e100-125VAC 60Hz (190-240VAC 50Hz) 60 Watts\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eDIMENSIONS\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003e19\" (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).\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification\"\u003e\n\u003cdiv class=\"sub-label\"\u003eWEIGHT\u003c\/div\u003e\n\u003cdiv class=\"model-specifications-section__specification-value\"\u003e22 lbs. (10 kg) Net: 30 lbs. (13.75 kg) Shipping\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Audio Research","offers":[{"title":"Default Title","offer_id":32176642490473,"sku":"000097","price":2100.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/products\/IMG_6866.jpg?v=1586797330"},{"product_id":"audio-research-sp6c-tube-preamp","title":"AUDIO RESEARCH SP6C TUBE PREAMP W\/PHONO","description":"\u003cp\u003eIn like new condition this Audio Research SP6C Tube Preamp has been refurbished and brought up to spec, and it is just a fantastic sounding tube preamp, especially the Phono Section. The following work was done on the unit:\u003c\/p\u003e\n\u003cdiv\u003e* All multi-section electrolytic capacitors have been replaced with long life discrete modern equivalents.\u003c\/div\u003e\n\u003cdiv\u003e* Select out of spec axial electrolytics replaced\u003c\/div\u003e\n\u003cdiv\u003e* All controls cleaned and lubricated\u003c\/div\u003e\n\u003cdiv\u003e* All tubes tested using our Amplitrex AT1000 tube tester- Any out of spec tubes have been replaced\u003c\/div\u003e\n\u003cdiv\u003e* Proper channel balance verified on line level and phono inputs\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e We acquired this unit along with an Audio Research D90 from the original owner which we also have up for sale. After the work was done we ran the two units together for a week in our shop where it performed flawlessly. From a smoke free, pet free and kid free house, The faceplate, body and cages are in excellent, like new condition.  The unit comes in the original Audio research double box with original owners manual. \u003cbr\u003e\u003c\/p\u003e","brand":"Audio Research","offers":[{"title":"Default Title","offer_id":39337058369641,"sku":"000274","price":2200.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/products\/IMG_0826.jpg?v=1617462791"},{"product_id":"golden-theater-gtx-1-multichannel-preamplifier","title":"Golden Theater GTX-1 Multichannel Preamplifier","description":"\u003cp\u003eFor sale, we have a fully tested Golden Theater GTX-1 Multichannel Preamplifier in perfect working order. The display is bright and clear. Gold RCA jacks, case are of high build quality.  The preamp is in very good physical condition, with only minor blemishes. The unit has been well cared for. See pictures for further details.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, several inches of polyethylene foam on all sides of the unit, and use water activated, fiber reinforced tape on all seams.\u003c\/span\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e \u003c\/span\u003e\u003c\/p\u003e","brand":"Golden Theater","offers":[{"title":"Default Title","offer_id":40792713101417,"sku":"000970","price":245.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/2AAC62E8-BF63-412C-8883-C777AF39AB5A_1_201_a.heic?v=1698000209"},{"product_id":"edwards-audio-mc1-phono-stage-psu1-power-supply","title":"Edwards Audio MC1 Phono Stage \u0026 PSU1 Power Supply","description":"\u003cp\u003eFrom talk electronics, we have a fine example of an Edwards Audio MC1 Phono Stage with the upgraded PSU1 Power Supply. The units are in very good physical condition, and in perfect working order. The MC1 unit is serial number 003, and the PSU1 power supply is serial number 53. A superb sounding phono stage, it is also very flexible. It plays both MM and MC cartridges, and settings can be changed by removing four screws, opening the unit and moving jumpers. A power cord, cable from power supply to preamp, and a copy of the owner's manual will be included in the sale. See pictures for further details.\u003c\/p\u003e\n\u003cp\u003eWe don't have the original box for these units, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, several inches of polyethylene foam on all sides of the pieces, and use water activated, fiber reinforced tape on all seams.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSpecifications For The MC1\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eType: MM\/MC solid-state stereo phonostage\u003cbr\u003eMax Input MC: 10mV\u003cbr\u003eMax Input MM: 100mV\u003cbr\u003eGain: 40\/50\/63 dB MM\/MC\u003cbr\u003eTHD Distortion: \u0026lt;0.008% 1kHz\u003cbr\u003eSignal To Noise Ratio: Ref 500uV (MC) 5mV (MM) -68dB\/-84dB\u003cbr\u003eRIAA Accuracy: Within 0.25dB\u003cbr\u003eStereo Separation: Better than 75dB from 20 Hz to 20 kHz\u003cbr\u003eInput Loading MC 100R with 2n2 capacitance\u003cbr\u003eInput Loading MM 47K\/1K0 with 120pF\u003cbr\u003eDamping 1K0\/10R\u003cbr\u003eDynamic Range: 110dB\u003cbr\u003eOutput Impedance: \u0026lt;10 Ohms\u003cbr\u003eMax Output Level: 10V RMS depending upon input\u003cbr\u003eDimensions: 114.5 x 47.5mm x 160 (WxHxD in mm)\u003cbr\u003eWeight: 2.2 lbs.\u003c\/p\u003e","brand":"Edwards Audio","offers":[{"title":"Default Title","offer_id":41014919659625,"sku":"001069","price":450.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/D61F79FA-44BC-4884-BCE7-2D9900DCAA44_1_201_a.heic?v=1705276264"},{"product_id":"audio-research-sp16l-line-stage-preamplifier","title":"Audio Research SP16L Line Stage Preamplifier w\/remote and Original boxes","description":"\u003cp\u003eFor sale, we have a one owner Audio Research SP16L Tube Line Stage Preamplifier. The preamp was cleaned and fully tested, and it is in perfect working order. The preamp uses 12AX7 tubes and comes installed with 3 JJ ECC83S\/12AX7's.  They were checked on our Amplitrex AT1000, and all three tested strong. A gorgeous sounding tube preamp with the convenience of having a remote control, we really enjoyed having it in our shop. We ran it for about a week in one of our house systems. \u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003eThe SP16 is completely single-ended with four sets of inputs  (CD, Tuner, Video and Aux) plus a Processor pass-through. There are two sets of main outputs for flexibility, plus a Tape out. The SP16 has a 12-volt trigger to turn on power amplifiers or other equipment, and full remote control of all functions including power, input selection, stereo\/mono, volume, and muting.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003ePhysically the unit is in very good condition, with only some minor blemishes. There is a light mark on the top of the unit, and  some light blemishes on the bottom. There are no dings, dents, or scratches, and really is minty unit. The remote control is in good condition and perfect working order. It was a bit \"tacky\" from the rubberized factory coating failing due to age. We removed the coating and the remote looks and feels much better. \u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eThe SP16L comes with the original owners manual, original remote control, power cable, and the original Audio Research Double box. \u003c\/p\u003e","brand":"Audio Research","offers":[{"title":"Default Title","offer_id":41032286273641,"sku":"001082","price":1495.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/5BA19008-5688-4BE3-90B2-C039180842C5_1_201_a.heic?v=1705859759"},{"product_id":"hengdong-audio-model-ja-3-linestage-preamp","title":"Hengdong Audio Science and Technology Company (Jungson) Model JA-3 Linestage Preamp","description":"\u003cp\u003eFor sale, we have a linestage preamp manufactured by the Hengdong Audio Science and Technology Company. The  Model JA-3 preamp has three inputs, one balanced, and two unbalanced. The output terminals are balanced. Upon research, it appears that the Hengdong Audio and ScienceTechnology Company is the manufacturer of Jungson audio products. This appears to be an early model, and while it does not have the Jungson name on it, it does have the same Logo. We could not find any information on the web about this model, but the company is still in business, and is currently manufacturing some nice gear. We bought a collection of audio gear from an audiophile, and this unit was included. Having no experience with this brand, we did not think much of it. Upon further inspection, we found that the build quality was quite good. The case is solid and heavy, underneath we noticed the two transformers, and a very well laid out design. We were very pleased with how the unit sounds. All pots and switches were cleaned, and then treated with Deoxit F5 and D5 respectively. \u003c\/p\u003e\n\u003cp\u003ePhysically the unit is in very good condition. There are a few scratches on the top cover toward the rear, and a small nick on the bottom left corner of the faceplate. The unit presents itself very well.\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, several inches of polyethylene foam on all sides of the unit, and use water activated, fiber reinforced tape on all seams.\u003c\/span\u003e\u003c\/p\u003e","brand":"Hengdong Audio Jungson","offers":[{"title":"Default Title","offer_id":41147553644649,"sku":"001087A","price":395.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/850659A0-F773-47DD-B6EF-CE70B42DC130_1_201_a.heic?v=1710086745"},{"product_id":"monolith-sound-ps1-phono-stage-w-acs-power-supply","title":"Monolithic Sound PS1 Phono Stage w\/ACS Power Supply","description":"\u003cp\u003eFor your consideration, we have a rare Monolithic Sound PS1 Phono Stage with a Monolithic sound ACS Power Supply. The PS-1 is a versatile phono stage, compatible with most moving-magnet and moving-coil phono cartridges. Rear panel DIP\u003cbr\u003eswitches allow selection of four gain settings, four impedance settings, three capacitance settings and a switchable subsonic filter.. The unit is in perfect working order, and sounds excellent. \u003c\/p\u003e\n\u003cp\u003ePhysically the unit is in good condition. The faceplate has some blemishes, the top has a few light scratches and the rest of the body has blemishes here and there. Overall the unit presents itself very well. Please see the many pictures in the listing for further details on the physical appearance. The separate ACS Power Supply has no cracks or damage, and is in very good condition. \u003c\/p\u003e\n\u003cp\u003eIncluded in the sale is the unit, power supply, and a copy of the one sheet owners manual that details all the settings for various cartridges. \u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense, use heavy duty boxes, several inches of polyethylene foam on all sides of the unit, and use water activated, fiber reinforced tape on all seams.\u003c\/span\u003e\u003c\/p\u003e","brand":"Monolithic Sound","offers":[{"title":"Default Title","offer_id":41495862313065,"sku":"001155","price":350.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/20C2AF40-99D2-438B-93C2-6F1D0C28EF7F_1_201_a.heic?v=1715531524"},{"product_id":"audio-research-sp15-silver","title":"Audio Research SP15 Hybrid Tube Preamplifier Serviced w\/Factory Boxes","description":"\u003cp\u003eThis very well cared for SP15 comes from the original owner, who purchased it in 1991. This is a minty unit, that has only minor blemishes, if any at all. In perfect working order, the preamp and power supply were both sent to Audio Research in October 2020 for a complete checkup. There was nothing wrong with the unit, but the previous owner wanted to have it gone through. The power supply was recapped, a number of resistors were replaced in the preamp, the phono stage was modified\/updated, and the tubes were replaced. All paperwork, and receipts are included in the sale, along with reviews, original and updated owners manuals. Being that the unit was serviced in late 2020, all we did was clean and then treat all the pots and switches with deoxit F5 and D5 respectively. We ran the unit in our house system for about three weeks, and it performed flawlessly. \u003c\/p\u003e\n\u003cp\u003eWe have had quite a few Audio Research preamps come through our shop, and we are never disappointed. This unit sounds exceptional, and has an excellent phono stage. \u003c\/p\u003e\n\u003cp\u003eThe units will ship in two separate factory double boxes, and we will then triple box them in order to preserve the factory boxes, and for added safety during transport. \u003c\/p\u003e\n\u003cp\u003eThe following is an Audio Research SP15 Review by James Leahy.\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eThe Audio Research SP15 was introduced to the world in 1988 and is a full functioning Pre-Amplifier with Inbuilt Phono Stage. As can be seen from the pictures, the SP15 is constructed on Two (2) Chassis, utilizing Aircraft-Quality Connectors and an Interconnect Cable Forty-Eight (48 \") Inches long. The Unit is divided into an Active Amplification Chassis (SP15) And A Power Supply Chassis (SP15PS).\u003cbr\u003e\u003cbr\u003eA Custom Interconnect Cable of longer length is available from Audio Research at additional cost, although some degradation of performance will occur as the Cable lengthens.\u003cbr\u003e\u003cbr\u003eThe Power Supply is in the pictures, as well as the Control Section.\u003cbr\u003e\u003cbr\u003eIf you are a Control Freak, this is the Pre-Amplifier for you. It has a plethora of functions to play with and is the ultimate in flexibility.\u003cbr\u003e\u003cbr\u003eThe Power Supply has Two (2) Controls, One is the Main Power and the other is the Auxiliary Power Outputs for various other components that can be Switched On or Off via the SP15.\u003cbr\u003e\u003cbr\u003eThere is a five level attenuation control that is designed to equalize source levels and give a huge range of volume control to the pre-amplifier. It is graded in 6dB increments and is adjustable down to -24dB.\u003cbr\u003e\u003cbr\u003eThe Volume Control is the usual Analogue Pot with Graduated Positions being used for this Multi-Ganged Heavy Gold Platted Unit designed to minimize Sonic Degradation of Microvolt Level Analogue Signals.\u003cbr\u003e\u003cbr\u003eThere is a Balance Control that is useful in some poor acoustical environments.\u003cbr\u003e\u003cbr\u003eThere is One (1) Pair of Balanced Outputs as well as Two (2) Pairs of Single Ended outputs. As always, I recommend using the Balanced Output to connect up to your Power Amplifier, if it has this available too.\u003cbr\u003e\u003cbr\u003eThe SP15 has Mono, Stereo, Left, Right and Reverse listening modes.\u003cbr\u003e\u003cbr\u003eThe Phono Circuit has impedance settings of 3, 10, 30, 100, and 47 K ohm.\u003cbr\u003e\u003cbr\u003eThere is also a 'Direct' Mode that in the \"Bypass\" position, directly connects the Attenuator to the Output of either the RIAA Compensated Phono Amplification Circuitry or a selected Line-Level Source (such as CD…),\u003cbr\u003e\u003cbr\u003eThe \"Balance\", and \"Mode\" Controls, as well as the \"Monitor\" Switch are removed from the Active Circuit path when this Switch is in operation.\u003cbr\u003e\u003cbr\u003eThe Bypass Switch is provided for use with Audiophile-Quality Program Material or whenever Maximum Fidelity to The Input Signal is desired.\u003cbr\u003e\u003cbr\u003e\u003cbr\u003eThere are Three (3) 6922 Vacuum tubes used in Intermediary Gain Stages in the Phono Section of the SP15.\u003cbr\u003e\u003cbr\u003eEach of the levels of Circuitry Amplification is provided with its own electronic regulation in the form of a \"Capacitance Multiplier,\" providing essentially \"zero\" impedance power supplies with essentially infinite isolation between circuit sections. Thus, the active circuitry is allowed to operate near theoretical performance levels.\u003cbr\u003e\u003cbr\u003eThe separate \"Active\" Chassis contains both the High-Gain, RIAA Equalized, Magnetic Phono Preamplifier and the \"Line\" Level Circuitry, plus all of the Inputs, Outputs and various Function Controls.\u003cbr\u003e\u003cbr\u003eExtensive use has been made of State-Of-The-Art Audio Materials, including such items as Polypropylene And Polystyrene Dielectric Capacitors, Metal Film Resistors, Wire-Wound Resistors, proprietary Point-To-Point Internal Wiring, Gold-Plated Input and Output Connectors, Heavily Gold-Plated Switches, and other high-quality components.\u003cbr\u003e\u003cbr\u003eThe SP15 is The Ultimate Pre-Amplifier even to this day that has an inbuilt Phono Section. The improvements over the much loved but not forgotten SP11 are as follows:\u003cbr\u003e\u003cbr\u003eLike the SP11, the new SP15 is a \"Hybrid\" Preamplifier using both Vacuum Tubes and Semiconductors as gain devices.\u003cbr\u003e\u003cbr\u003eHowever, the SP15 uses only three (3) tubes compared to the SP11's six;\u003cbr\u003e\u003cbr\u003eand whereas the SP11's tubes were employed in both phono and line sections, the SP15's tubes are confined to the Phono Section alone.\u003cbr\u003e\u003cbr\u003eAs in the SP11, these tubes are not required to be selected, low-noise types.\u003cbr\u003e\u003cbr\u003eThe changes in the SP15 line section (as compared to the SP11) are not limited to choice of gain devices. Resistance to input overloads, reduction of inherent noise levels, resistance to inter-input crosstalk and dynamic headroom have all been achieved as a result of circuit redesign in this area.\u003cbr\u003e\u003cbr\u003eConvenience features and controls remain similar to the SP11, but with some significant additions. The familiar \"Gain\" control has been replaced by a 5-position \"Attenuator\" switch having 6dB increments, resulting in better sonics while maintaining a useful selection of settings to match the output characteristics of both phono cartridges and CD players.\u003cbr\u003e\u003cbr\u003eTape and dubbing functions remain identical to the SP11.\u003cbr\u003e\u003cbr\u003eOn the back of the SP15 are new provisions for either Conventional (i.e. Single-Ended) or Balanced Output connection(s). Balanced connections can be made via the RCA jacks labeled \"Direct\" and \"Invert,\" or by using the new industrial \"XLR\" connector provided.\u003cbr\u003e\u003cbr\u003eLike the SP11, the SP15 is a Two (2) Chassis design isolating Power Supply functions from sensitive Preamplifier Circuits, reducing the opportunity for magnetic field effects to degrade sonic performance.\u003cbr\u003e\u003cbr\u003eA Toroid Power Transformer minimizes mechanical buzz and \"hum.\" See Installation Instructions for details on proper placement of the Two (2) chassis relative to one another.\u003cbr\u003e\u003cbr\u003eThe SP15 reflects a further evolution and refinement of the idea that state-of-the-art preamplifier performance can be combined with real-word user convenience and system flexibility.\u003cbr\u003e\u003cbr\u003eCare has been taken to optimize the sonic performance of a variety of popular input options -- video, compact disc, tuner and analogue tape, as well as unsurpassed phono reproduction.\u003cbr\u003e\u003cbr\u003eSonic Evaluations:\u003cbr\u003e\u003cbr\u003eThe SP15 was fired up with Kim Carnes timeless classic Bette Davis Eyes from the 'Mistaken Identity' album (EMI Records, 1981). The soundstage was both wide and deep. I was more than a little impressed with the sonic maturity of this product even by today's standards.\u003cbr\u003e\u003cbr\u003eThe SP15 had an impressive level of drive and slam compared to the LS15 that I reviewed at the same time.\u003cbr\u003e\u003cbr\u003eThe SP15 was in a different class sonically and had a marvelous top end that was not harsh or brittle. The midrange was smooth without any obvious flaws or trouble spots. Bass extension was well defined and quick.\u003cbr\u003e\u003cbr\u003eOn the whole it is a very worthwhile unit with great features that would surpass all in the SP line up that I have heard. Even the latest SP16 that I have tried and did not take to.\u003cbr\u003e\u003cbr\u003eFor all those who wish to know about the quality of the Phono Stage in the SP15, read on.\u003cbr\u003e\u003cbr\u003eThe internal phono stage of the SP15 is the best that I have heard in an integrated component. However this is not saying much.\u003cbr\u003e\u003cbr\u003eI have done extensive comparisons with the SP15 and the separate Audio Research PH5 Phono Stage and the difference in quality is huge.\u003cbr\u003e\u003cbr\u003eAs I would have expected, I was just not prepared for the level of difference that could be heard when I paired up the SP15 with the PH5. It was JAW DROPPING. If you are into your vinyl then the PH5 is a must have as you can by-pass the phono section in the SP15 while still maintaining use of all the other great benefits of this wonderful classic unit.\u003cbr\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eSPECIFICATIONS:\u003c\/p\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eFREQUENCY RESPONSE\u003c\/div\u003e\n\u003cdiv\u003eHigh level input: ±1dB 0.2Hz to 100kHz. -3dB below 0.1Hz and above 200kHz. Phono input: ±.2dB of RIAA 20Hz to 40kHz. ±1dB of RIAA 1.0Hz to 100kHz.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eDISTORTION (THD)\u003c\/div\u003e\n\u003cdiv\u003eHarmonic distortion: Less than .005% at 2V RMS output, 5Hz to 20kHz (Typically less than .001% at midband, phono or line input). Intermodulation distortion: Less than .003% at 2V RMS output\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eNOISE \u0026amp; HUM\u003c\/div\u003e\n\u003cdiv\u003eIHF weighted, shorted input: Output (Gain down): 6µV (110dB below rated output). Input (High level): 3µV equivalent input (110dB below 1V input). Phono: 0.15µV equivalent input (76dB below 1mV input)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eGAIN\u003c\/div\u003e\n\u003cdiv\u003eAt 1kHz, bypass mode: Phono input to tape output: 46dB (0.2V output from 1mV input). Phono input to main output: 75dB (0.175mV input for 1V output). High level input to main output: 29dB (36mV input for 1V output).\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eINPUT IMPEDANCE\u003c\/div\u003e\n\u003cdiv\u003ePhono: Front panel selectable 47K, 100, 30, 10, 3 ohms. Phono input capacitance: 150 pF at 10kHz. High level: 20K ohms or higher, depending on switch functions.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eOUTPUT IMPEDANCE\u003c\/div\u003e\n\u003cdiv\u003e200 ohms main, direct, inverted outputs. 500 ohms tape output. Recommended load 60K-100K ohms and 100pF (20Kohms minimum, 1000pF maximum)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eOUTPUT POLARITY\u003c\/div\u003e\n\u003cdiv\u003eTape outputs, direct output: Non-inverting. Invert output: Inverting. Main outputs (2): Selectable non-inverting or inverting. All outputs may be used simultaneously.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eMAXIMUM INPUTS\u003c\/div\u003e\n\u003cdiv\u003ePhono: 350 mV RMS at 1kHz, 1200 mV RMS at 10kHz (0.1 second maximum duration, 6dB less if continuous). High level: 25V RMS.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eRATED OUTPUTS\u003c\/div\u003e\n\u003cdiv\u003e2V RMS 1Hz to 100kHz main, direct, inverted outputs. (Maximum 80V RMS at 0.2% THD at 1kHz into 60K ohm load with 2.85V RMS high level input).\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003ePOWER SUPPLIES\u003c\/div\u003e\n\u003cdiv\u003e-\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eTUBE COMPLEMENT\u003c\/div\u003e\n\u003cdiv\u003e(3) 6DJ8\/ECC88\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003ePOWER REQUIREMENTS\u003c\/div\u003e\n\u003cdiv\u003e95-135VAC 60Hz, 190-270VAC 50\/60Hz, 130 Watts maximum\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eOTHER\u003c\/div\u003e\n\u003cdiv\u003eFilter: 25Hz Hi-pass phono subsonic 6dB\/octave rolloff (to eliminate ringing) with transition to 12dB\/octave at 10Hz. Front panel switchable phono only. Controls (6): Gain, Attenuator, Balance, Mode, Input, Impedance. Switches (8): Tape monitor, Copy, Tape 1\/2, Tape 1to2 \/ 2to1, Mute, Invert phase, Bypass, Filter.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eDIMENSIONS\u003c\/div\u003e\n\u003cdiv\u003e(Each chassis, EIA Rack panel mounting) 19\" (48 cm) W x 5 ¼\" (13.4 cm) H x 10 ¼\" (26 cm) D. Handles extend 1 ⅝\" (4.1 cm) forward of panel. Interconnect cable extends 4\" behind rear of chassis.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003eWEIGHT\u003c\/div\u003e\n\u003cdiv\u003eSP-15: 14 lbs. (6.4 kg) Net, 23 lbs. (10.5 kg) Shipping. SP-15PS: 15 lbs. (6.8 kg) Net, 23 lbs. (10.5 kg) Shipping. Total: 29 lbs. (13.2 kg) Net, 46 lbs. (21.0 kg) Shipping.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Audio Research","offers":[{"title":"Default Title","offer_id":42293486452841,"sku":"001468","price":3200.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/6B369DF7-4322-409B-A0C0-65D174937B92_1_105_c.jpg?v=1747603803"},{"product_id":"audio-research-reference-5-preamplifier","title":"Audio Research Reference 5 Preamplifier","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eFor your consideration, we have a minty Audio Research Reference 5 Preamplifier. This one owner preamp has been well cared for over the years with limited use and with only 70 hours of playtime. See photo of the display showing 70 tube hours on the preamp. The Reference 5 was paired with a Burmester 911 MKII Amplifier to run a pair of JM Labs Mini Utopia speakers, both of which we also have for sale. (The Burmester recently sold) The Reference 5 is extremely clean, both inside and out with no flaws of note. Please see the many pictures for further details.\u003cmeta charset=\"utf-8\"\u003e\u003c\/p\u003e\n\u003cp\u003eOn our bench the preamp checked out perfectly.  We pulled all the tubes, and tested them on our Amplitrex tube tester. All tubes tested strong in as new condition as the unit had very limited use since it was purchased new. In our listening room, paired with the Burmester, it performed flawlessly. We just loved this preamp, and amp setup. \u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003eThe Reference 5 will ship with the factory remote, AC cord, and original owners manual. The tubes will need to be pulled for safe shipping. We will box each tube and label them with their tube location. \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u003cmeta charset=\"utf-8\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, several inches of polyethylene foam on all sides of the unit, and use water activated, fiber reinforced tape on all seams.\u003c\/span\u003e\u003c\/p\u003e","brand":"Audio Research","offers":[{"title":"Default Title","offer_id":42553751044201,"sku":"001587","price":4500.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/7DEB2FFE-7CBF-46BB-AE35-80FB6F9F66B7_1_201_a.heic?v=1757954887"},{"product_id":"audio-research-line-stage-vacuum-tube-preamplifier-model-ls26-high-definition","title":"Audio Research LS26 Line Stage Vacuum Tube Preamplifier","description":"\u003cp\u003eTaken in on a trade, we have the Audio Research LS26 Line Stage Vacuum Tube Preamplifier. A one owner unit, it is in perfect working order, and very good physical condition. The display is bright and sharp, and the original remote functions as it should. According to the original owner, he never changed the original tubes, and they currently have 1269 hours on them. While still sounding very good, we are including a brand new set of Electro Harmonix Gold Pin 6H30Pi tubes. We ran the new tubes for about an hour and they sounded excellent. They should sound even better with some more break in time. We are including both sets of tubes with the purchase. \u003c\/p\u003e\n\u003cp\u003ePhysically the unit is in very good condition. There are some feet marks on the top of the unit, and some blemishes here and there. The bottom of the unit has many small, light scratches where the flat side of three brass cones were used as the feet in the previous setup. There are no dents or deep scratches, and the unit presents itself very well. The original remote shows some wear, but it is in perfect working order. Please see the many pictures in the listing for further details.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, and polyethylene foam when boxing up our gear for shipping. \u003c\/p\u003e","brand":"Audio Research","offers":[{"title":"Default Title","offer_id":43038105337961,"sku":"001735","price":2900.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/801B05C1-ED42-4DB5-AAA9-E62102A601A3_1_201_a.heic?v=1774300979"},{"product_id":"threshold-model-fet-ten-hl-field-effect-transistor-high-level-preamplifier","title":"Threshold Model FET ten\/hl Field Effect Transistor High Level Preamplifier","description":"\u003cp\u003eHere we have a Threshold Model FET ten\/hl Field Effect Transistor High Level Preamplifier. This reference line level preamp designed by Nelson Pass, is well regarded, and is of a very high build quality. It uses discrete FETs throughout. This Line Level preamp has tape outputs, a selector switch for five inputs, and a high quality balance and volume control. The ten\/hl has a clean and sophisticated layout with discrete components, and a GOLD plated circuit board. It comes with an outboard power supply.\u003c\/p\u003e\n\u003cp\u003eThe unit has been fully tested, and it is in excellent working condition. Physically the preamp is in very good condition with only minor blemishes. The faceplate is clean, all edges are sharp, and there are no dents or deep scratches in the unit. See the pictures in the listing for further details. \u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, and polyethylene foam when boxing up our gear for shipping. \u003c\/p\u003e\n\u003cp\u003eFrom Threshold:\u003c\/p\u003e\n\u003cp\u003eWith the Threshold FET Ten you will experience the musical accuracy, focus, and detail of a truly exceptional high fidelity instrument.\u003c\/p\u003e\n\u003cp\u003eThe circuit designs embodied in the Threshold FET Ten employ engineering concepts at the forefront of audio technology which do not lose information or gain distortion and maintain the precise signal content and relationships enabling a spatially accurate soundstage of palpable ambience.\u003c\/p\u003e\n\u003cp\u003eIt's flawless level of construction and finish are the product of an assembly staff who take personal pride in their craftsmanship and the electronic component parts which form the circuits of the FET Ten are the finest available to provide assurance of lasting performance and value.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eSpecifications:\u003cbr\u003eFET 10\/H: Line-level control center. Inputs:\u003c\/p\u003e\n\u003cp\u003eAuxiliary, FM\/AM Tuner, CD Player, Video Audio, 2 Tape Monitors. Outputs: 2 Tape Record, Main to power amp.\u003c\/p\u003e\n\u003cp\u003eControls: Source, Mode (Stereo, Reverse, Invert, Mono), Signal Distribution (Monitor Tape 1 or 2, Copy 1 to 2, Copy 2 to 1), Volume, Balance.\u003c\/p\u003e\n\u003cp\u003eVoltage gain: 20dB max.\u003c\/p\u003e\n\u003cp\u003eFrequency response: 1.5Hz–150kHz +0, –3dB. Max output: 20V. THD: 0.01% at 1V out.\u003c\/p\u003e\n\u003cp\u003eOutput impedance: 100 ohms.\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eDimensions:\u003cbr\u003e19.0 in. W X 2.0 in. H X 6.5 in. D.\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eWeight:\u003cbr\u003e4.5 Lbs.\u003c\/p\u003e","brand":"Threshold","offers":[{"title":"Default Title","offer_id":43038142365801,"sku":"001737","price":1995.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/4B9B8C15-1680-47C9-A05B-C5EA6A034A2E_1_201_a.heic?v=1774303563"},{"product_id":"ps-audio-4-5-preamp-w-mm-or-mc-phono-stage","title":"PS Audio 4.5 Preamp w\/ MM or MC Phono Stage","description":"\u003cp\u003eFor your consideration, we have a PS Audio 4.5 Preamp for sale. The unit is in perfect working order, and very good physical condition. The preamp comes with a separate power supply, and has built in phono stage. A switch on the board allows you to choose between MM and MC.\u003c\/p\u003e\n\u003cp\u003eWe checked the preamp out on our bench and found no bulging capacitors, or any signs of heat stress. When testing the unit it showed even channel balance. All pots and switches were cleaned and treated. \u003c\/p\u003e\n\u003cp\u003eAfter being gone over, we ran the unit in one of our systems for about 4 hours where it performed perfectly.\u003c\/p\u003e\n\u003cp\u003eSee pictures for further details. \u003c\/p\u003e\n\u003cp\u003eThe preamp will ship with the power supply, and owner's manual.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, and polyethylene foam when boxing up our gear for shipping. \u003c\/p\u003e","brand":"PS Audio","offers":[{"title":"Default Title","offer_id":43247584084073,"sku":"001763","price":450.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/D620419B-88B5-4713-B272-8E3E543AF175_1_201_a.heic?v=1779821980"},{"product_id":"krell-phantom-preamplifier-2-piece","title":"Krell Phantom Preamplifier w\/Remote","description":"\u003cp\u003eFor your consideration, we have an extremely rare Krell Phantom two piece preamplifier. This Reference unit is a two box system, consisting of the preamp controls in one box, and the power supply in another. The unit comes from the original owner, and it is in perfect working order. On our bench, and in our listening bay, the unit performed flawlessly. We had this unit in our bay for a few weeks, and fell in love with it.\u003c\/p\u003e\n\u003cp\u003ePhysically the unit is very clean both inside and out. The unit comes with the cord to connect the preamp and power supply, original remote, with torx wrench to change the remote batteries, AC cord, and a copy of the quick start guide for the unit. See photos for further details on condition.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eThe Phantom will ship fully insured, and a signature will be required upon delivery. \u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense and use heavy duty boxes, with polyethylene foam when boxing up our gear for shipping. Our packing meets or exceeds factory packaging. \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Krell","offers":[{"title":"Default Title","offer_id":47831992729705,"sku":"001809","price":5500.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/1805D82E-ECF2-4B64-B108-44C8483DC2A7_1_201_a.heic?v=1784924610"},{"product_id":"denon-precision-audio-component-stereo-graphic-equalizer-de-70","title":"DENON DE-70 Stereo Graphic Equalizer","description":"\u003cp\u003eFor your consideration we have a rare Denon DE-70 Stereo Graphic Equalizer. This rare unit is in perfect working order, and good physical condition. All switches and pots were cleaned and treated with Deoxit D5 and F5 respectively.  Physically the unit has many scratches on the top and sides. The faceplate is in very good shape, and there are no dents in the unit. With all this being said, the Equalizer presents itself well. See the many pictures in the listing for further details.\u003c\/p\u003e\n\u003cp\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense, use heavy duty boxes, and polyethylene foam when boxing up our gear for shipping.\u003c\/p\u003e","brand":"Denon","offers":[{"title":"Default Title","offer_id":47843281043561,"sku":"001811","price":425.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/3A54D7FC-1613-472B-8AC8-86DD44195FFB_1_201_a.heic?v=1785260550"},{"product_id":"mcintosh-c28-stereophonic-preamplifier","title":"McIntosh C28 Stereophonic Preamplifier","description":"\u003cp\u003eFor sale, we have a beautiful example of a Mcintosh C28 preamplifier. The unit came to us in working order, and only needed a light service. On our bench the C28 performed as it should. We then ran the unit in our final test area for two days and it performed flawlessly.\u003c\/p\u003e\n\u003cp\u003eThe bulbs that backlight the faceplate were replaced with LED bulbs, and all eight switch bulbs were replaced as well.  All pots and switches were cleaned, and then treated with Deoxit F5 and D5 respectively. \u003cmeta charset=\"utf-8\"\u003eThe unit sounds fantastic, and has a great dual phono section. \u003c\/p\u003e\n\u003cp\u003ePhysically the preamp is in very good condition. The glass is intact however there are some \u003cmeta charset=\"utf-8\"\u003ebubbles including in middle, some smaller ones at top right, and little subtle ones in top right corner. The knobs are in very good shape, and there are no dents or deep scratches on the unit. There are some blemishes on the top edge of the faceplate, along with some marks on the side chrome trim pieces. There are light scratches and blemishes on the top, sides and bottom as well. With all this being said, the unit presents itself very well. Please see the many pictures in the listing for further details. \u003c\/p\u003e\n\u003cp\u003eThe C28 will ship in a new Mcintosh factory fresh double box. \u003c\/p\u003e","brand":"Mcintosh","offers":[{"title":"Default Title","offer_id":47865806946409,"sku":"001815","price":1995.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/1086048C-D2F4-4BAC-A7D9-FA753E0AFE8C_1_201_a.heic?v=1785781407"},{"product_id":"bryston-sp3-surround-processor-preamp","title":"Bryston SP3 Surround Processor\/Preamp","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eFor sale, we have a great example of the \u003cmeta charset=\"utf-8\"\u003eBryston SP3 Surround Processor\/Prea\u003cwbr\u003emp. This is an earlier version of the SP3, and it does not support 4K. It can be sent into Bryston for an upgrade as they are still manufacturing the SP3. \u003c\/wbr\u003e\u003c\/p\u003e\n\u003cp\u003eThe unit is in good working order, and the display is bright. It's a very nice sounding preamp. The unit came from the original owner, and it includes the original remote, owner's manual, and an AC cord. \u003c\/p\u003e\n\u003cp\u003ePhysically the unit has some small nicks, and blemishes on the faceplate and unit. However, there are no dents or deep scratches. The preamp looks and presents itself very well. Please see the many pictures in the listing for further details. \u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eWe don't have the original box for this unit, but we take packaging and shipping seriously. We spare no expense, use heavy duty boxes, and polyethylene foam when boxing up our gear for shipping.\u003c\/p\u003e","brand":"Bryston","offers":[{"title":"Default Title","offer_id":48003201695849,"sku":"001830","price":2500.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0267\/5212\/2985\/files\/CD6B074C-314C-4F71-9182-20D2EEED99E3_1_105_c.jpg?v=1788728864"}],"url":"https:\/\/recordmarthifi.com\/collections\/pre-amps.oembed?page=2","provider":"Record Mart HiFi","version":"1.0","type":"link"}