{"product_id":"cayin-c9ii-dual-nutube-portable-tube-headphone-amplifier-demo-unit","title":"Cayin C9ii Dual NuTube Portable Tube Headphone Amplifier [DEMO UNIT]","description":"\u003cdiv\u003e\u003cspan style=\"color: #cc0000;\"\u003e\u003cb\u003eDEMO UNIT\u003cbr\u003e\u003cbr\u003eThis product has been tested and assessed by our team, and is sold in working and resellable condition.\u003c\/b\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan style=\"color: #cc0000;\"\u003eThis product may feature minor physical blemishes, and may therefore not be in pristine physical condition. If there is any\u003cspan\u003e \u003c\/span\u003e\u003ci\u003enotable\u003c\/i\u003e\u003cspan\u003e \u003c\/span\u003eblemish present however, we will provide additional information below this disclaimer, accompanied with photos above which highlight the notable imperfections listed.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"color: #cc0000;\"\u003eWe cannot provide any further photos of the unit's current physical condition beyond those available in this listing.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"color: #cc0000;\"\u003e\u003ci\u003e*If applicable*\u003c\/i\u003e\u003cspan\u003e \u003c\/span\u003e- This product has been tested to ensure that the device functions, and the battery discharges properly. Unfortunately we cannot provide any exact charging or battery life information.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"color: #cc0000;\"\u003eIf this product is missing any factory accessories, the missing accessories will be listed under this disclaimer.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"color: #cc0000;\"\u003eThis product is strictly available for online purchase only, and cannot be viewed, purchased or collected in store.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan style=\"color: #cc0000;\"\u003eThis product comes with full warranty as per the Warranty section on this listing unless otherwise specified. If there is no warranty period outlined in the Warranty section below, please\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"mailto:info@addictedtoaudio.com.au\" rel=\"noreferrer\" target=\"_blank\"\u003eget in touch with our Customer Care team\u003c\/a\u003e\u003cspan style=\"color: #cc0000;\"\u003e for more information.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eGen5 Nutube 6P1 Vacuum Tube Audio Circuit \u003cbr\u003e\u003c\/strong\u003eCayin has applied this vacuum tube to multiple products, including the N8, C9, N8ii, and N30LE, and now the C9ii. After years of continuous circuit experimentation and technical refinement, Cayin has equipped the C9ii with an adjustable anode (plate) voltage feature and the highly praised Classic and Modern dual tube timbre. This adjustable plate voltage feature offers two levels: high and low.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDual Tube Timbre Circuit\u003c\/strong\u003e\u003cbr\u003eModern Sound: Introduces a large-loop negative feedback system, with total gain determined by the large-loop negative feedback circuit. By incorporating negative feedback over multiple amplification stages, the total harmonic distortion (THD) will be reduced significantly. The harmonic distortion characteristics and sound signature lean more toward a modern style, with greatly reduced thermal noise and a slightly cleaner tube sound. The original C9 was designed with a similar NFB circuit. \u003c\/p\u003e\n\u003cp\u003eClassic Sound: No large-loop negative feedback; each stage operates independently through local feedback, with the overall gain determined by the cumulative gain of each stage. The distortion characteristics of the tube amplification circuit dominate the sound signature, resulting in a higher THD value. The distribution of harmonic distortion and the sensor signature exhibit a classic vacuum tube amplification circuit, with relatively more thermal noise and a richer vacuum tube presentation. The N8 DAP was designed with a similar NFB circuit. \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAnode (High\/Low) \u003c\/strong\u003e\u003cbr\u003eCayin introduces a new feature, “Anode” to C9ii. The High\/Low adjustable anode (plate) voltage further enriches and refines the range of vacuum tube timbre. The working principle is that applying different operating voltages to the plate of the vacuum tube alters its operating state, ultimately affecting the sound signature of the timbre circuit. This mainly manifests in changes in audio linearity, and it will adjust the overlay, spectrum, amplitude, and ratio of second-order harmonic, resulting in perceptible audible differences.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eClassic + Anode (H): The richest tube sound, with intense emotional depth, suitable for vocal music with a lot of details.\u003c\/li\u003e\n\u003cli\u003eClassic + Anode (L): Slightly lighter tube sound, suitable for vocals with thicker tones.\u003c\/li\u003e\n\u003cli\u003eModern + Anode (H): Less tube character, with moderate smoothing in the midrange and a slight sweetness added.\u003c\/li\u003e\n\u003cli\u003eModern + Anode (L): Minimal tube coloration, without affecting resolution and definition.\u003c\/li\u003e\n\u003cli\u003eSolid State sound: Balanced across the entire frequency range, musical without tube coloration.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eFully Discrete, Fully Symmetric Differential Headphone Amplifier \u003c\/strong\u003e\u003cbr\u003eThe C9ii's headphone amplification circuit is significantly different from that of the first-generation C9. While both amplifiers employ a fully discrete, fully differential four-channel headphone amplification circuit, the C9ii adopts a fully symmetrical circuit architecture. \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFully-symmetric Headphone Amplifier\u003c\/strong\u003e\u003cbr\u003eCayin has designed a three-stage amplification circuit to embrace the fully symmetric design into C9ii: a differential input stage, a voltage amplification stage, and a power driver stage. \u003c\/p\u003e\n\u003cp\u003eStage One: Symmetric JFET Common-source Differential input amplifier.\u003c\/p\u003e\n\u003cp\u003eStage Two: Symmetric BJT Common-emitter Push-Pull Differential Voltage Amplifier. \u003c\/p\u003e\n\u003cp\u003eStage Three: Symmetric BJT Common-collector Push-Pull Parallel Current Amplifier(emitter follower).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNegative FeedBack (NFB)\u003c\/strong\u003e \u003cbr\u003eThe C9ii has an integrated precision control circuit that allows the headphone amplifier to operate in various modes such as NFB\/LFB, Class A\/Class AB, Hyper, single-ended, and balanced input\/output modes.\u003c\/p\u003e\n\u003cp\u003eOn the C9ii, when NFB is on (indicator light on), the audio output presents more spatiality with stellar dynamic range, excellent transient response, and relatively fewer harmonics, delivering more neutral sound with impressive detail and speed. Audiophiles frequently associate these changes with “higher resolution.” On the other hand, when NFB is off (indicator light off), the audio output displays richer harmonics. You can hear a more cohesive and full-bodied presentation, with stronger imaging and more textured and elastic mid-bass frequencies. \u003c\/p\u003e","brand":"Cayin","offers":[{"title":"Default Title","offer_id":44009214181510,"sku":"CAYIN.C9II.DEMO.9IIAF8T8","price":3199.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0875\/3864\/files\/cayin-c9ii-dual-nutube-portable-tube-headphone-amplifier.jpg?v=1727320827","url":"https:\/\/addictedtoaudio.com.au\/products\/cayin-c9ii-dual-nutube-portable-tube-headphone-amplifier-demo-unit","provider":"Addicted To Audio","version":"1.0","type":"link"}