{"product_id":"threshold-t50-class-a-amplifier","title":"Threshold T50 Class A Amplifier - 50 Watts","description":"\u003cp\u003e\u003cb\u003eGeneral:\u003c\/b\u003e\u003cbr\u003eThe T-50 is an interesting amplifier in the Threshold range, delivering pure Class A operation with 50 watts into 8 ohms and 100 watts into 4 ohms.\u003cbr\u003e\u003cbr\u003eIt came later than the more famous Stasis series, representing a shift in design philosophy away from hybrid topologies toward a more minimalist, purist approach. Rather than combining a Class A front end with a high-power output stage, the T-50 operates fully in Class A,\u003cbr\u003e\u003cbr\u003eThe result is an excellent sound with typical class A smoothness, musicality (and heat). We really enjoyed the way this amplifier sounded at our test rig. \u003cbr\u003e\u003cbr\u003eIn addition to its sound we also like its compact chassis and overall design, It can fit on narrow shelfs that other class A amplifiers cannot.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eSkyFi Cosmetic Notes:\u003c\/b\u003e\u003cbr\u003eFaceplate wear is present. All other surfaces also show wear. Overall the condition is presentable.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eSkyFi Technical Notes:\u003c\/b\u003e\u003cbr\u003eThis amplifier came in with a bad single ended \/ balanced switch on the left channel. We replaced the defective switch and set the DC offset and Bias. While we had the unit on the bench we noticed that the right channel appears to have been serviced at some point in the past.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eOwnership:\u003c\/b\u003e\u003cbr\u003eSecond Owner\u003cbr\u003e\u003cbr\u003e\u003cb\u003eConnections:\u003c\/b\u003e\u003cbr\u003eRCA, XLR, IEC Power\u003cbr\u003e\u003cbr\u003e\u003cb\u003eGeneral Sound:\u003c\/b\u003e\u003cbr\u003eSmooth, uncolored, undistorted natural and clean\u003cbr\u003e\u003cbr\u003e\u003cb\u003eCosmetic Condition:\u003c\/b\u003e\u003cbr\u003e6\/10 = Fair. Three to four minor scratches, or one major scratch. 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\u003eJust the unit 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\u003e- Power Output: 50 Watts per channel into 8 ohms (Pure Class A).\u003cbr\u003e- Design: Bipolar output transistors (8 per channel).\u003cbr\u003e- Transformer: 500 VA Transformer.\u003cbr\u003e- Frequency Response: 20 Hz – 20 kHz, ±0.1 dB.\u003cbr\u003e- Voltage Gain: 26.8 dB.\u003cbr\u003e- Input Impedance: 100k ohms balanced, 50k ohms single-ended.\u003cbr\u003e- Damping Factor: \u0026gt;800, 20 Hz – 20 kHz into 8 ohms.\u003cbr\u003e- Signal to Noise Ratio: \u0026gt;80 dB (ref. 1W).\u003cbr\u003e\u003cbr\u003e\u003cb\u003eDimensions:\u003c\/b\u003e\u003cbr\u003eHeight: 50mm (1.97 inches) Width: 400mm (15.75 inches) Length: 1140mm (44.88 inches)\u003cbr\u003e\u003cbr\u003e\u003cb\u003eWeight:\u003c\/b\u003e\u003cbr\u003e45 lbs.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eApproximate Age:\u003c\/b\u003e\u003cbr\u003e1994\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\/collections\/our-kimber-kable-collection\/products\/kimber-kable-ascent-series-hero-analog-interconnects-pair-balanced-xlr-connectors-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Kable - BALANCED XLR Connectors\u003c\/a\u003e - Better\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https:\/\/skyfiaudio.com\/collections\/our-kimber-kable-collection\/products\/kimber-kable-summit-series-silver-streak-analog-interconnects-pair-balanced-xlr-connectors-new\" rel=\"noopener\" target=\"_blank\"\u003eKimber Kable - BALANCED XLR Connectors\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":47931681243390,"sku":"107504","price":3605.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0003\/3275\/9084\/files\/threshold-t50-class-a-amplifier-50-watts-700.jpg?v=1773779116","url":"https:\/\/skyfiaudio.com\/en-au\/products\/threshold-t50-class-a-amplifier","provider":"SkyFi Audio","version":"1.0","type":"link"}