{"product_id":"igs-audio-one-leveling-amplifier","title":"IGS Audio One Leveling Amplifier","description":"\u003cdiv lang=\"en\"\u003e\n  \u003cp\u003e\u003cstrong\u003eIGS Audio One Leveling Amplifier\u003c\/strong\u003e is a mono tube optical compressor inspired by the Teletronix LA-2A — a fully tube signal path with transformer-balanced input and output and a T4Bx photocell as the gain reduction element. Input transformer is IGS Audio 2510, output transformer IGS 15k\/600; two 6N1P-EW dual triodes in the audio circuit and a 6N2P-EW + 6AQ5 pair in the photocell control circuit. Maximum gain reduction of 36 dB, dynamic range above 110 dB(A), 40 W internal power supply. Stereo Link via rear RCA connector.\u003c\/p\u003e\n\n  \u003ch3\u003eT4Bx Photocell and Tube Topology — LA-2A Character in a New Design\u003c\/h3\u003e\n  \u003cp\u003eThe LA-2A is defined by optical compression: an electroluminescent panel drives a photoresistor, which attenuates the signal proportionally to its illumination. Attack and release timing derive from the photocell's physics rather than potentiometer settings — attack at 1 ms, release from 0.5 to 5 s with the 50% point at 60 ms. This means the compressor breathes with the material: fast attack catches transients, but the long release tail ensures the return to unity is always gradual. IGS Audio uses its own T4Bx photocell as a modern equivalent of the T4B, hand-matched for unit-to-unit consistency. Compress mode produces a soft knee and musical compression — the standard setting for vocals, acoustic guitar, and brass; Limit mode sharpens the knee and responds more aggressively to transients. Three controls complete the interface: Peak Reduction (threshold and depth of gain reduction), Gain (makeup gain to 30 dB), and the Compress\/Limit switch. The VU meter toggles between output level and gain reduction display.\u003c\/p\u003e\n\n  \u003ch3\u003eFull Tube Circuit and Transformer Color\u003c\/h3\u003e\n  \u003cp\u003eFour tubes across the signal path and control circuit mean that every stage — amplification, sidechain, photocell drive — contributes tube harmonics to the output signal. THD+N of 85 dB(A) is typical for a studio-grade tube optical compressor: higher distortion than a transistor design, but harmonically musical and part of the character. The IGS Audio 2510 input transformer and 15k\/600 output transformer add transformer coloration — midrange density and warmth that complements the photocell's organic response. Two One LA units linked via the rear RCA Stereo Link connector operate as a stereo pair with independent per-channel adjustment.\u003c\/p\u003e\n\n  \u003ch3\u003eKEY FEATURES\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eMono tube optical compressor — inspired by the Teletronix LA-2A\u003c\/li\u003e\n    \u003cli\u003eT4Bx photocell (IGS Audio Custom, equivalent of T4B) — hand-matched per unit\u003c\/li\u003e\n    \u003cli\u003eFull tube circuit: 2 × 6N1P-EW (audio) + 6N2P-EW + 6AQ5 (sidechain control)\u003c\/li\u003e\n    \u003cli\u003eTransformers: IGS Audio 2510 (input) + IGS 15k\/600 (output)\u003c\/li\u003e\n    \u003cli\u003eCompress and Limit modes (switchable)\u003c\/li\u003e\n    \u003cli\u003eControls: Peak Reduction, Gain, Compress\/Limit switch\u003c\/li\u003e\n    \u003cli\u003eMax gain: 30 dB; max gain reduction: 36 dB\u003c\/li\u003e\n    \u003cli\u003eAttack: 1 ms; release: 0.5–5 s (50% at 60 ms)\u003c\/li\u003e\n    \u003cli\u003eInput and output impedance: 600 Ω (balanced)\u003c\/li\u003e\n    \u003cli\u003eMax input: +16 dBu; max output: +18 dBu\u003c\/li\u003e\n    \u003cli\u003eDynamic range: \u0026gt;110 dB(A) at 1 kHz, +24 dBu\u003c\/li\u003e\n    \u003cli\u003eVU meter: output level or gain reduction (switchable)\u003c\/li\u003e\n    \u003cli\u003eStereo Link: RCA connector (rear panel)\u003c\/li\u003e\n    \u003cli\u003eInternal power supply, 115\/230 V AC, 40 W\u003c\/li\u003e\n    \u003cli\u003eChannel configuration: mono (stereo pair via Stereo Link)\u003c\/li\u003e\n    \u003cli\u003eMade in: Poland\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eTECHNICAL SPECIFICATIONS\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eType: mono tube optical compressor\/leveling amplifier\u003c\/li\u003e\n    \u003cli\u003eCompression element: T4Bx photocell (IGS Audio Custom)\u003c\/li\u003e\n    \u003cli\u003eTubes: 2 × 6N1P-EW (audio), 1 × 6N2P-EW (sidechain), 1 × 6AQ5 (sidechain)\u003c\/li\u003e\n    \u003cli\u003eInput transformer: IGS Audio 2510\u003c\/li\u003e\n    \u003cli\u003eOutput transformer: IGS 15k\/600\u003c\/li\u003e\n    \u003cli\u003eInput impedance: 600 Ω (balanced)\u003c\/li\u003e\n    \u003cli\u003eOutput impedance: 600 Ω (balanced)\u003c\/li\u003e\n    \u003cli\u003eOperating level: +4 dBu\u003c\/li\u003e\n    \u003cli\u003eMax input level: +16 dBu\u003c\/li\u003e\n    \u003cli\u003eMax output level: +18 dBu\u003c\/li\u003e\n    \u003cli\u003eDynamic range: \u0026gt;110 dB(A) at 1 kHz, +24 dBu\u003c\/li\u003e\n    \u003cli\u003eMax gain: 30 dB\u003c\/li\u003e\n    \u003cli\u003eMax gain reduction: 36 dB\u003c\/li\u003e\n    \u003cli\u003eAttack: 1 ms\u003c\/li\u003e\n    \u003cli\u003eRelease: 0.5–5 s (50% at 60 ms)\u003c\/li\u003e\n    \u003cli\u003eTHD+N: 85 dB(A)\u003c\/li\u003e\n    \u003cli\u003eStereo Link: RCA (rear panel)\u003c\/li\u003e\n    \u003cli\u003ePower: internal, 115\/230 V AC, 40 W\u003c\/li\u003e\n    \u003cli\u003eMade in: Poland\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e","brand":"IGS Audio","offers":[{"title":"Default Title","offer_id":54001626808657,"sku":"47369","price":1584.44,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8741\/0769\/files\/IGSAudioOneLevelingAmplifier.jpg?v=1781115368","url":"https:\/\/wrdtunes.com\/fr\/products\/igs-audio-one-leveling-amplifier","provider":"Wired Tunes","version":"1.0","type":"link"}