{"product_id":"audio-research-i-70-integrated-amplifier","title":"Audio Research I\/70 Integrated Amplifier","description":"\u003ch1\u003eAudio Research I\/70 Integrated Amplifier\u003c\/h1\u003e\n\u003ch3\u003e70 Watts Per Channel of KT120 Tube Power With Auto-Bias, Flexible Preamplifier Outputs, and Optional Phono and Digital Modules\u003c\/h3\u003e\n\u003cp\u003eThe Audio Research I\/70 brings the company's tube preamplifier and power-amplifier expertise together in a single integrated amplifier. Four KT120 output tubes deliver 70 watts per channel, while an output transformer derived from the Reference 75 amplifier connects the I\/70 directly to Audio Research's established separates heritage.\u003c\/p\u003e\n\u003cp\u003eThe I\/70 is designed and built by hand at Audio Research's Minnesota facility, where each amplifier is twice tested and individually auditioned in the company's reference system. Its industrial design takes cues from the REF330M, with anodized top and bottom plinths, a fully enclosed transformer array, machined aluminum, meshwork, and distinctive Audio Research badging.\u003c\/p\u003e\n\u003ch4\u003eTube Power Without Manual Biasing\u003c\/h4\u003e\n\u003cp\u003eAuto-bias eliminates the routine adjustment traditionally associated with many tube power amplifiers. The I\/70 continuously maintains the operating bias of its four KT120 output tubes, making tube ownership considerably more straightforward while maintaining proper operating conditions.\u003c\/p\u003e\n\u003cp\u003eThe amplifier provides dedicated 4-ohm and 8-ohm output taps for matching a range of loudspeakers. Audio Research rates the I\/70 at 70 watts per channel continuously from 20 Hz–20 kHz.\u003c\/p\u003e\n\u003ch4\u003eIndependent Preamplifier and Power-Amplifier Sections\u003c\/h4\u003e\n\u003cp\u003eThe I\/70 incorporates independent tube preamplifier and tube power-amplifier sections. Stereo preamplifier outputs provide additional system flexibility, including the ability to feed powered subwoofers equipped with line-level inputs.\u003c\/p\u003e\n\u003cp\u003eAn active tube preamplifier section and 75-step volume control provide a broad range of level adjustment, particularly useful when moving among sources and recordings with substantially different output levels.\u003c\/p\u003e\n\u003ch4\u003eOptional Phono and Digital Capability\u003c\/h4\u003e\n\u003cp\u003eThe standard analog input complement consists of three sets of single-ended inputs and one balanced XLR input. Optional phono and digital boards expand the I\/70's source capabilities.\u003c\/p\u003e\n\u003cp\u003eThe optional phonostage accommodates both moving-magnet and moving-coil cartridges, with gain settings selectable from the I\/70 remote. Moving-coil loading is adjustable from 50–1,000 ohms.\u003c\/p\u003e\n\u003cp\u003eThe optional digital board uses an AKM Velvet Sound DAC and provides USB, optical, coaxial, and Bluetooth connectivity. Incoming digital signals are upsampled by the DAC section.\u003c\/p\u003e\n\u003ch4\u003eHeadphone Listening From the Main Output Tubes\u003c\/h4\u003e\n\u003cp\u003eRather than relying on a separate convenience headphone circuit, the I\/70's headphone output is driven by its KT120 output tubes. This gives headphone listeners access to the amplifier's primary tube output stage for personal listening.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e70 Wpc continuous tube output from 20 Hz–20 kHz\u003c\/li\u003e\n\u003cli\u003eFour KT120 output tubes with automatic biasing\u003c\/li\u003e\n\u003cli\u003eOutput transformers derived from the Audio Research Reference 75 amplifier\u003c\/li\u003e\n\u003cli\u003eIndependent tube preamplifier and tube power-amplifier sections\u003c\/li\u003e\n\u003cli\u003e75-step volume control\u003c\/li\u003e\n\u003cli\u003eThree single-ended analog inputs and one balanced XLR analog input as standard\u003c\/li\u003e\n\u003cli\u003eStereo preamplifier outputs for external amplification or powered subwoofers with line-level inputs\u003c\/li\u003e\n\u003cli\u003e4-ohm and 8-ohm speaker output taps\u003c\/li\u003e\n\u003cli\u003eHeadphone output driven by the KT120 output tubes\u003c\/li\u003e\n\u003cli\u003eOptional MM\/MC phonostage with remotely selectable gain and adjustable MC loading from 50–1,000 ohms\u003c\/li\u003e\n\u003cli\u003eOptional AKM-based digital board with USB, optical, coaxial, and Bluetooth inputs\u003c\/li\u003e\n\u003cli\u003eEight total inputs with both optional phono and digital boards installed\u003c\/li\u003e\n\u003cli\u003eAvailable with black or silver anodized plinths\u003c\/li\u003e\n\u003cli\u003eHand-built, twice tested, and individually auditioned at Audio Research's Minnesota facility\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cp\u003e\u003cb\u003ePower Output:\u003c\/b\u003e 70 Wpc continuous from 20 Hz–20 kHz; 1 kHz total harmonic distortion typically 1% per channel, below 0.1% at 1 W\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003ePower Bandwidth (-3 dB Points):\u003c\/b\u003e 10 Hz–22 kHz\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eFrequency Response (-3 dB Points At 1 W):\u003c\/b\u003e 7 Hz–30 kHz\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eInput Sensitivity:\u003c\/b\u003e 1.25 V RMS for rated output\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eInput Impedance:\u003c\/b\u003e 100 kohms balanced; 48 kohms single-ended\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eOutput Polarity:\u003c\/b\u003e Non-inverting; balanced input pin 2+ (IEC-268)\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eStandard Analog Inputs:\u003c\/b\u003e Three single-ended, one balanced\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eMaximum Inputs With Optional Phono And Digital Boards:\u003c\/b\u003e 8\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eOutput Taps:\u003c\/b\u003e 8 ohms, 4 ohms\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003ePower Requirements (US):\u003c\/b\u003e 105–130 V AC, 60 Hz; 420 W at rated output, 220 W at idle\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eTubes Required:\u003c\/b\u003e Two matched pairs KT120; three 6922 (one input, two driver)\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eDimensions (H × W × D):\u003c\/b\u003e 8.25\" x 16.5\" x 13.5\" (210 x 420 x 340 mm)\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eWeight:\u003c\/b\u003e 55 lb. (25 kg)\u003c\/p\u003e","brand":"Audio Research","offers":[{"title":"Black \/ No Addons","offer_id":53876967145656,"sku":"ARCI70-BLK","price":9950.0,"currency_code":"USD","in_stock":true},{"title":"Black \/ Optional DAC Card","offer_id":53876967178424,"sku":"ARC-I70-BLK-DAC","price":10950.0,"currency_code":"USD","in_stock":true},{"title":"Black \/ DAC \u0026 Phono Card (Preinstalled)","offer_id":53876967211192,"sku":"ARC-I70-BLK-DAP","price":11450.0,"currency_code":"USD","in_stock":true},{"title":"Black \/ Optional Phono Card","offer_id":53876967243960,"sku":"ARC-I70-BLK-PHN","price":10950.0,"currency_code":"USD","in_stock":true},{"title":"Natural (Silver) \/ No Addons","offer_id":53876967276728,"sku":"ARC-I70-NAT","price":9950.0,"currency_code":"USD","in_stock":true},{"title":"Natural (Silver) \/ Optional DAC Card","offer_id":53876967309496,"sku":"ARC-I70-NAT-DAC","price":10950.0,"currency_code":"USD","in_stock":true},{"title":"Natural (Silver) \/ DAC \u0026 Phono Card (Preinstalled)","offer_id":53876967342264,"sku":"ARC-I70-NAT-DAP","price":11450.0,"currency_code":"USD","in_stock":true},{"title":"Natural (Silver) \/ Optional Phono Card","offer_id":53876967375032,"sku":"ARC-I70-NAT-PHN","price":10950.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1564\/1247\/files\/I-70-1-1500px-1.jpg?v=1786381852","url":"https:\/\/upscaleaudio.pro\/products\/audio-research-i-70-integrated-amplifier","provider":"Upscale Audio","version":"1.0","type":"link"}