{"product_id":"threshold-s-300-series-1-amplifier-150w-nelson-pass-designed","title":"Threshold S\/300 Series 1 Amplifier - 150W Nelson Pass Designed","description":"\u003cp\u003e\u003cb\u003eGeneral:\u003c\/b\u003e\u003cbr\u003eThe Threshold S\/300 is an impressive amplifier designed by the legendary Nelson Pass. Capable of a healthy 150 Watts into 8ohms it has plenty of power for the majority of speakers on the market. \u003cbr\u003e\u003cbr\u003eAs a member of the Stasis series, the S\/300 was engineered for high-fidelity performance, utilizing Threshold’s proprietary “Stasis” topology. Stasis amplification circuits combine the best of class A and class AB designs. \u003cbr\u003e\u003cbr\u003eThe build quality of this amplifier is also excellent and worth mentioning. Super high quality aluminum heatsinks and a thick faceplate are standouts. Clearly a piece that was overbuilt.\u003cbr\u003e\u003cbr\u003eIn testing we found that every speaker we tried with it sounded great. Included with the amplifier will be a 14AWG power cord and its original owners manual.\u003cbr\u003e\u003cbr\u003eLike all electronics leaving our shop, we will package this amplifier with care.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eSkyFi Cosmetic Notes:\u003c\/b\u003e\u003cbr\u003eWe could only find two very light marks on the faceplate - Right side behind the handle, Left side near the top of the handle. Overall condition is excellent.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eSkyFi Technical Notes:\u003c\/b\u003e\u003cbr\u003eBoth channels test to over 150W into 8 ohms before clipping. Bias has been set to the appropriate level for hot A\/B operation as outlined in the schematic.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eOwnership:\u003c\/b\u003e\u003cbr\u003eSecond Owner\u003cbr\u003e\u003cbr\u003e\u003cb\u003eConnections:\u003c\/b\u003e\u003cbr\u003eRCA, IEC power, 5 Way speaker binding posts.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eGeneral Sound:\u003c\/b\u003e\u003cbr\u003eBig beautiful musical sound with little fatigue.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eCosmetic Condition:\u003c\/b\u003e\u003cbr\u003e8\/10 = Very Good. Excellent front faceplate, one minor flaw on chassis side or top. See our detailed rating description \u003ca href=\"https:\/\/skyfiaudio.com\/pages\/our-rating-scale\" target=\"_blank\"\u003ehere\u003c\/a\u003e.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eWorking Condition:\u003c\/b\u003e\u003cbr\u003eWorking perfectly and tested in our lab and listening room.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eIncluded:\u003c\/b\u003e\u003cbr\u003eUnit, manual, and power cord.\u003cbr\u003e\u003cbr\u003e\u003cb\u003ePacking:\u003c\/b\u003e\u003cbr\u003eWill be packed using our highly developed in-house process and custom packing materials.\u003ciframe width=\"1280\" height=\"720\" src=\"https:\/\/www.youtube.com\/embed\/wuWesEecAbE?\u0026amp;autoplay=1\u0026amp;mute=1\" title=\"This Is How We Pack Sensitive Electronics at SkyFi Audio, Less Than 0.2% Shipping Damage\"\u003e\u003c\/iframe\u003e\u003cb\u003eSpecs:\u003c\/b\u003e\u003cbr\u003ePower output: 150 watts per channel into 8Ω (stereo)\u003cbr\u003eFrequency response: 7Hz to 100kHz\u003cbr\u003eTotal harmonic distortion: 0.1%\u003cbr\u003eGain: 26.6 dB\u003cbr\u003eSignal to noise ratio: 100dB\u003cbr\u003eSemiconductors: 14 x transistors per channel (output)\u003cbr\u003e\u003cbr\u003e\u003cb\u003eDimensions:\u003c\/b\u003e\u003cbr\u003e8.72 x 19 x 13.125 inches\u003cbr\u003e\u003cbr\u003e\u003cb\u003eWeight:\u003c\/b\u003e\u003cbr\u003e56 lbs.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eApproximate Age:\u003c\/b\u003e\u003cbr\u003e1983\u003cbr\u003e\u003cbr\u003e\u003cb\u003eLink to Manual:\u003c\/b\u003e\u003cbr\u003e\u003ca href=\"https:\/\/www.hifiengine.com\/manual_library\/threshold-audio\/s-300.shtml\" target=\"_blank\"\u003eClick Here\u003c\/a\u003e\u003cbr\u003e\u003cbr\u003e\u003cb\u003eRecommended Cables:\u003c\/b\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/products\/kimber-kable-hero-interconnects-pair-rca-ultraplate-or-wbt-connectors-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Kable - RCA Interconnects\u003c\/a\u003e - Better\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/products\/kimber-kable-silver-streak-interconnects-pair-rca-ultraplate-or-wbt-connectors\" rel=\"noopener\" target=\"_blank\"\u003eKimber Kable - RCA Interconnects\u003c\/a\u003e - Best\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/products\/kimber-kable-8tc-8-tc-ascent-speaker-cables-pair-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Kable - Speaker Cables\u003c\/a\u003e - Better\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/products\/kimber-kable-summit-series-monocle-xl-speaker-cables-pair-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Summit Series Monocle XL Speaker Cables (PAIR)\u003c\/a\u003e - Best\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/products\/kimber-kable-summit-series-bifocal-xl-bi-wire-speaker-cables-pair-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Summit Series BiFocal XL Bi-Wire Speaker Cables (PAIR)\u003c\/a\u003e - Best If Applicable\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/products\/kimber-kable-pk14-pk-14-ascent-power-cord-brand-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Kable - Power Cords\u003c\/a\u003e - Better\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/products\/kimber-kable-ascent-series-pk10-pk-10-power-cord-brand-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Kable - Power Cords\u003c\/a\u003e - Best\u003cbr\u003e\u003cbr\u003e\u003cb\u003eTesting Process:\u003c\/b\u003e\u003cbr\u003eWe 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 PCBs 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.\u003cbr\u003e\u003cbr\u003eIf the amplifier passes visual inspection, we move on to a controlled power on sequence using a Sencore safety analyzer to monitor current draw in real time. Once the amplifier is determined to be safe to operate, we connect it to full AC mains for function and power testing. We connect the speaker outputs of the amplifier to a Sencore PA81 Power Analyzer which acts as a dummy load, DC offset monitor, and oscilloscope interface. We start with a low level 1 KHz test signal at the amplifier's input and slowly increase its amplitude while monitoring the output on an oscilloscope for signs of noise, clipping, distortion, or improper channel balance. We continue increasing the signal level until the amplifier reaches clipping. \u003cbr\u003e\u003cbr\u003eAt this point we take an output power measurement and compare it to the spec sheet of the amplifier to verify proper performance. If the device under test has both balanced and single ended inputs they are both tested at this time.\u003cbr\u003e\u003cbr\u003eWe finish off the bench evaluation with a 1 KHz square wave check and a 20 Hz to 20 KHz sine sweep to assess the amplifier's frequency response characteristics. \u003cbr\u003e\u003cbr\u003eThis battery of tests will usually reveal if the amplifier has any issues that need further attention.\u003cbr\u003e\u003cbr\u003eBefore the device leaves the bench, we perform a listening test with actual music using a variety of preferred test tracks. Our benches are outfitted with familiar monitor speakers which help us identify inconsistencies that will not always show up on our test gear. The main things that we are listening for are hum or noise with no signal present, proper center image, clicks, pops, or any other obvious undesirable audio characteristics.\u003cbr\u003e\u003cbr\u003eIf the unit passes all of these tests it is moved to our long term testing rig where we simulate real word operating conditions for 6-8 hours minimum. This allows us to monitor the unit for signs of thermal runaway or intermittent issues that only crop up when the unit has fully come up to temperature.\u003cbr\u003e\u003c\/p\u003e","brand":"Threshold","offers":[{"title":"Default Title","offer_id":47931681308926,"sku":"107503","price":0.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0003\/3275\/9084\/files\/threshold-s-300-series-1-amplifier-150w-nelson-pass-designed-719.jpg?v=1773779126","url":"https:\/\/skyfiaudio.com\/products\/threshold-s-300-series-1-amplifier-150w-nelson-pass-designed","provider":"SkyFi Audio","version":"1.0","type":"link"}