{"product_id":"thoress-f2a11-integrated-amplifier","title":"THÖRESS F2a11 Integrated Amplifier","description":"\u003cp\u003eThe THÖRESS F2a11 Integrated Amplifier is a purist, all-tube statement piece built around the legendary F2a11 power tube. Originally designed by Siemens \u0026amp; Halske for demanding post and telegraph applications (Postleitröhre), the F2a11 is revered for its unmatched build quality and sonic neutrality. In this amplifier, THÖRESS utilizes these vintage professional pentodes in \u003cstrong\u003eSingle-Ended Triode (SET) operation\u003c\/strong\u003e, delivering 6 watts of exquisite, class-A power. Designed specifically for high-efficiency loudspeakers, the F2a11 Integrated offers a sonic presentation that rivals classic 300B or 2A3 designs but with a distinctively powerful, clear, and natural character. Handcrafted in Germany with meticulous point-to-point wiring, this amplifier is not merely an audio component; it is a lifetime investment in musical truth.\u003c\/p\u003e\n\u003ch5\u003eKey Features:\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eF2a11 Single-Ended Triode Mode:\u003c\/strong\u003e Utilizes NOS Siemens F2a11 power pentodes wired in triode mode for 2x 6 Watts of pure Class-A output.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eZero Feedback Topology:\u003c\/strong\u003e A minimalist circuit design with absolutely no global negative feedback ensures dynamic integrity and phase coherence.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVintage Driver Stage:\u003c\/strong\u003e employs a highly linear 12SN7GT double-triode (octal base) driver tube for perfect synergy with the output stage.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManual Dual-Mono Volume:\u003c\/strong\u003e Features separate high-grade ALPS rotary potentiometers for each channel, allowing precise balance adjustment without a dedicated balance circuit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIn-House C-Core Transformers:\u003c\/strong\u003e Equipped with proprietary output transformers (OPT) and a mains transformer wound in-house by THÖRESS for ultra-low noise and optimal load matching.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVersatile Load Matching:\u003c\/strong\u003e Solderable jumpers on the output transformers allow precise matching to 4, 8, or 16-ohm loudspeakers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustrial Build Quality:\u003c\/strong\u003e Non-magnetic aluminum chassis with a powder-coated finish and anodized printing, evoking the aesthetic of 1950s professional laboratory equipment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003eThe F2a11 Advantage\u003c\/h5\u003e\n\u003cp\u003eThe F2a11 tube is a marvel of German engineering, originally built to last 10,000 hours in critical telecommunications repeaters. When strapped in triode mode, it exhibits linearity comparable to the finest directly heated triodes (DHTs). THÖRESS exploits this to create an amplifier that combines the \"glow\" and texture of a SET amp with the speed and resolution typical of professional gear. It is the perfect engine for high-sensitivity horns or full-range drivers (93dB+ recommended).\u003c\/p\u003e\n\u003ch5\u003ePurist Control\u003c\/h5\u003e\n\u003cp\u003eTo maintain the integrity of the signal, the F2a11 Integrated eschews remote control and complex switching. Volume is controlled via two independent knobs (one for left, one for right), allowing the user to set perfect channel balance manually. The input selector is a high-quality rotary switch located near the rear jacks to minimize signal path length, operated via an extension shaft.\u003c\/p\u003e\n\u003ch5\u003eMeticulous Construction\u003c\/h5\u003e\n\u003cp\u003eInside the retro-styled chassis lies a work of art. The circuit is constructed entirely by hand using point-to-point air wiring—no printed circuit boards interfere with the signal. High-grade foil-in-oil capacitors and precision resistors are used throughout. The power supply features a vibration-isolated mains transformer and high-grade electrolytic capacitors made in Germany, ensuring a noise floor that is virtually non-existent.\u003c\/p\u003e\n\u003ch5 class=\"p1\"\u003eThe Listening Room Difference\u003c\/h5\u003e\n\u003cp class=\"p1\"\u003eWe’re a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on trust, not hype. Whether you’re visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don’t just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.\u003c\/p\u003e\n\u003ch5\u003eSpecifications\u003c\/h5\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eTopology\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003eSingle-Ended Triode (SET), Zero Feedback\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eOperation Class\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003ePure Class A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003ePower Output\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e2 x 6 Watts (into 4, 8, or 16 Ohms)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eOutput Tubes\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e2 x Siemens F2a11 (NOS)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eDriver Tube\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e1 x 12SN7GT (Octal Double-Triode)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eInputs\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e3 x Line Level RCA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eVolume Control\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003eDual Mono Manual Rotary Potentiometers (ALPS)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eOutput Matching\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e4, 8, 16 Ohm (via internal soldered jumpers)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eTransformers\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003eIn-house Hand-wound C-Core Output and Mains Transformers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eDimensions (W x D x H)\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e150 x 595 x 330 mm (Depth includes terminals)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eWeight\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003e18 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cb\u003eOrigin\u003c\/b\u003e\u003c\/td\u003e\n\u003ctd\u003eHandmade in Aachen, Germany\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"THÖRESS","offers":[{"title":"Default Title","offer_id":67848638169457,"sku":"THF2A11","price":7929.39,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0923\/5215\/1921\/files\/thoeress-f2a11-1-Photoroom.jpg?v=1792518784","url":"https:\/\/sliyden.store\/products\/thoress-f2a11-integrated-amplifier","provider":"sliyden.store","version":"1.0","type":"link"}