{"product_id":"parasound-halo-a21","title":"Parasound Halo A21+ Stereo Power Amplifier","description":"\u003ch3 data-start=\"319\" data-end=\"375\"\u003eHalo A21+ — Power You Can Feel, Control You’ll Love\u003c\/h3\u003e\n\u003cp data-start=\"377\" data-end=\"640\"\u003e\u003cbr\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-start=\"381\" data-end=\"404\"\u003eParasound Halo A21+\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003edelivers commanding power with effortless musicality. At 300 W per channel into 8 Ω (500 W into 4 Ω), and up to 1,000 W bridged, it drives any loudspeaker with authority while keeping the sound spacious, controlled, and fatigue-free.\u003c\/p\u003e\n\u003cp data-start=\"642\" data-end=\"949\"\u003eBased on\u003cspan\u003e \u003c\/span\u003e\u003cstrong data-start=\"651\" data-end=\"691\"\u003elegendary John Curl’s circuit design\u003c\/strong\u003e, the A21+ refines Parasound’s most celebrated power amp for today’s systems—blending raw performance with elegant simplicity. Balanced XLR and RCA inputs, 2 Ω stability, and flexible bridging make it an ideal match for both stereo and home theater setups.\u003c\/p\u003e\n\u003cp data-start=\"951\" data-end=\"996\"\u003ePraised by audiophiles and reviewers alike:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"999\" data-end=\"1076\"\u003e\u003cem data-start=\"999\" data-end=\"1074\"\u003e“The soundstage just bloomed. Bass is crisp… mids and highs are singing.”\u003c\/em\u003e\u003c\/li\u003e\n\u003cli data-start=\"1079\" data-end=\"1156\"\u003e\u003cem data-start=\"1079\" data-end=\"1154\"\u003e“Ridiculously high damping… bass is tight and controlled at all volumes.”\u003c\/em\u003e\u003c\/li\u003e\n\u003cli data-start=\"1159\" data-end=\"1232\"\u003e\u003cem data-start=\"1159\" data-end=\"1230\"\u003e“Delightful and satisfying from the first note… impossible to fault.”\u003c\/em\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1234\" data-end=\"1293\"\u003eWinner of multiple awards and recommendations, including:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong data-start=\"1349\" data-end=\"1392\"\u003eSecrets of Home Theater \u0026amp; High Fidelity\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e–\u003cspan\u003e \u003c\/span\u003e\u003cem data-start=\"1395\" data-end=\"1424\"\u003eBest Stereo Power Amplifier\u003c\/em\u003e\u003cspan\u003e \u003c\/span\u003e(2024)\u003cstrong data-start=\"1296\" data-end=\"1311\"\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1296\" data-end=\"1346\"\u003e\n\u003cstrong data-start=\"1296\" data-end=\"1311\"\u003eStereophile\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e–\u003cspan\u003e \u003c\/span\u003e\u003cem data-start=\"1314\" data-end=\"1337\"\u003eRecommended Component\u003c\/em\u003e \u003c\/li\u003e\n\u003cli data-start=\"1436\" data-end=\"1507\"\u003e\n\u003cstrong data-start=\"1436\" data-end=\"1457\"\u003eFuture Audiophile\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e– \"\u003cem data-start=\"1460\" data-end=\"1498\"\u003eBest Affordable Audiophile Power Amp\"\u003c\/em\u003e\u003cem data-start=\"1460\" data-end=\"1498\"\u003e\u003c\/em\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eSpecifications: \u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePower Output – Stereo Mode (0.1% THD)\u003c\/strong\u003e\u003cbr\u003e300 watts x 2, 8 Ω both channels driven\u003cbr\u003e500 watts x 2, 4 Ω both channels driven\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePower Output – Bridged Mode (0.1% THD)\u003c\/strong\u003e\u003cbr\u003e1000 watts x 1, 8 Ω\u003cbr\u003eBridged 4 Ω operation is not recommended\u003cbr\u003e\u003cbr\u003ePower measurement are at 120 VAC:\u003cbr\u003e0.1% THD, RMS continuous power,\u003cbr\u003efull audio band (20 Hz - 20 kHz)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCurrent Capacity\u003c\/strong\u003e\u003cbr\u003e60 amps peak, per channel\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSlew Rate\u003c\/strong\u003e\u003cbr\u003e\u0026gt; 130 volts per microsecond\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFrequency Response\u003c\/strong\u003e\u003cbr\u003e5 Hz - 100 kHz, +0\/-3 dB\u003cbr\u003e20 Hz - 20 kHz, +0\/-0.25 dB\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTotal Harmonic Distortion (THD)\u003c\/strong\u003e\u003cbr\u003e\u0026lt; 0.1 % at full power\u003cbr\u003e\u0026lt; 0.03 % at typical listening levels\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIM Distortion\u003c\/strong\u003e\u003cbr\u003e\u0026lt; 0.04 %\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTIM\u003c\/strong\u003e\u003cbr\u003eUnmeasurable\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eInter-channel Crosstalk\u003c\/strong\u003e\u003cbr\u003e\u0026gt; 80 dB at 1 kHz\u003cbr\u003e\u0026gt; 70 dB at 20 kHz\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eInput Impedance\u003c\/strong\u003e\u003cbr\u003eUnbalanced: 33 kΩ\u003cbr\u003eBalanced: 66 kΩ,(33 kΩ per leg)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTotal Gain\u003c\/strong\u003e\u003cbr\u003e29 dB\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eInput Sensitivity for 28.28 V Output into 8 Ω\u003c\/strong\u003e\u003cbr\u003eUnbalanced: 1 V\u003cbr\u003eBalanced: 1 V per leg\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eS\/N Ratio\u003c\/strong\u003e\u003cbr\u003e\u0026gt; 115 dB, input shorted, IHF A-weighted\u003cbr\u003e\u0026gt; 110 dB, input shorted, unweighted\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDamping Factor\u003c\/strong\u003e\u003cbr\u003e\u0026gt; 1100 at 20 Hz\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDC Trigger Requirements\u003c\/strong\u003e\u003cbr\u003e+9 Vdc to +12 Vdc, 5 mA\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAudio Trigger Requirements\u003c\/strong\u003e\u003cbr\u003e2 mV - 10 mV\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eXLR Pin Identification\u003c\/strong\u003e\u003cbr\u003e1 = Ground (Shield)\u003cbr\u003e2 = Positive\u003cbr\u003e3 = Negative (Return)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003cbr\u003eWidth: 17-5\/8\" (448 mm)\u003cbr\u003eHeight without feet: 7-1\/8\" (181 mm)\u003cbr\u003eHeight with feet: 7-3\/4\" \" (197 mm)\u003cbr\u003eDepth: 20\" (508 mm)\u003cbr\u003eDepth with cables: 21-1\/2\" (546 mm)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNet Weight\u003c\/strong\u003e\u003cbr\u003e71 lb. (32.2 kg)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShipping Weight\u003c\/strong\u003e\u003cbr\u003e88 lb. (39.9 kg)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePower Requirement\u003c\/strong\u003e\u003cbr\u003eStandby: 1 Watt\u003cbr\u003eIdle (no music playing): 160 Watts\u003cbr\u003eTypical Listening levels: 300 Watts\u003cbr\u003eMaximum: 1400 Watts\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFeatures:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e300 watts x 2 @ 8 Ω RMS, both channels driven\u003c\/li\u003e\n\u003cli\u003e500 watts x 2 @ 4 Ω RMS, both channels driven\u003c\/li\u003e\n\u003cli\u003e1000 watts x 1 @ 8 Ω, in bridged mode\u003c\/li\u003e\n\u003cli\u003eCircuitry designed by legendary John Curl\u003c\/li\u003e\n\u003cli\u003eHigh bias Class A\/AB operation\u003c\/li\u003e\n\u003cli\u003e60 amperes peak current per channel\u003c\/li\u003e\n\u003cli\u003eStable with speaker impedance dips to 1.5 Ω\u003c\/li\u003e\n\u003cli\u003eBalanced inputs with discrete circuits\u003c\/li\u003e\n\u003cli\u003eCHK Infinium, custom 5-way speaker binding posts\u003c\/li\u003e\n\u003cli\u003eGold-plated RCA input \u0026amp; loop output jacks\u003c\/li\u003e\n\u003cli\u003eDirect-coupled signal path, no capacitors or inductors\u003c\/li\u003e\n\u003cli\u003eDC Servo and relay protection circuits\u003c\/li\u003e\n\u003cli\u003eAC turn-on inrush surge protection with relay bypass\u003c\/li\u003e\n\u003cli\u003eJFET input stage, MOSFET driver stage\u003c\/li\u003e\n\u003cli\u003e16 beta-matched 15 ampere, 60 MHz bipolar output transistors\u003c\/li\u003e\n\u003cli\u003e1.3 kVA shielded toroid transformer w\/ independent windings for each channel\u003c\/li\u003e\n\u003cli\u003eIndependent power supplies for input stage, driver stage and output stage\u003c\/li\u003e\n\u003cli\u003e108,000 µF filter capacitors for output stages\u003c\/li\u003e\n\u003cli\u003eFull power is rated all the way down to 5Hz for unrestricted low-end bass\u003c\/li\u003e\n\u003cli\u003eHarris hyper-fast soft-recovery bridge diode rectifiers\u003c\/li\u003e\n\u003cli\u003eAutomatic turn-on by 12 V trigger or audio sensing\u003c\/li\u003e\n\u003cli\u003e4 rack space chassis with rear carry handles\u003c\/li\u003e\n\u003cli\u003eRack mount hardware is included\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Parasound","offers":[{"title":"Default Title","offer_id":62769415192735,"sku":null,"price":7350.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0555\/5532\/6111\/files\/a21__front_black_57ce9b30-ae6d-433a-b399-b33e8fca262d.jpg?v=1776118689","url":"https:\/\/altitudoaudio.ca\/products\/parasound-halo-a21","provider":"Altitudo Audio","version":"1.0","type":"link"}