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"There was a time when sound didn’t roll off automated assembly lines, but instead took shape amidst the scent of molten solder and the glow of vacuum tubes in small workshops within the province of Vicenza (Italy). The first sign is always the same: that orange glow filtering through the glass of the tube, a breath of light that heralds the music. Within this landscape of electric ferment, the figure of Andy Roman emerges. To enter his world is to rediscover a devotion to detail that feels legendary today: hand-wired circuits where every solder joint was a signature, and every transformer a jealously guarded secret."
Today, that electric fervor has evolved into a tangible legacy. Years spent chasing harmonic perfection have yielded a definitive collection of instruments: from the dynamic roar of the Fat Boy to the absolute transparency of the 300B Dual Mono power amp, and the visceral presence of the Onken systems.
These are no longer projects in progress, but completed works resting in their state of grace. This space is the diary of an acoustic journey spanning over twenty years. We present here what has been built, so that the orange glow of the tubes may continue to tell its story to those who, even today, seek the soul beyond the signal.
🔊 Andy Roman Hi-Fi
Reference Inductive Load Preamplifier
"A state-of-the-art control component engineered for absolute high-fidelity home reproduction. This preamplifier stands as the nerve center of a linear playback system, where extreme point-to-point craftsmanship converges with an esoteric circuit topology to guarantee absolute signal transparency."
📐 ARCHITECTURE & CIRCUIT PHILOSOPHY
• The Core of Gain: The circuit architecture centers on the strictly matched, ultra-high transconductance 6S45 single triode. This specific selection ensures linear voltage amplification, stable coupling, and microscopic resolution completely free from harshness.
• Anode Choke (Inductive Loading): Unlike conventional preamplifiers that dissipate energy across a load resistor—compromising dynamics—this model utilizes a dedicated anode choke. This configuration maintains a nearly horizontal dynamic load line, reducing intrinsic harmonic distortion to near-zero levels while unlocking unprecedented dynamic headroom and voltage swing.
• Vacuum Tube Rectification: The implementation of a dedicated rectifier tube guarantees a progressive turn-on ramp for the plate voltage, securing absolute immunity against the high-frequency switching noise typical of solid-state diodes.
• Extreme Passive Filtration: A complex multi-stage CLCL (Inductor-Capacitor-Inductor-Capacitor) filter network combined with CR stages completely neutralizes residual AC ripple. Working in perfect synergy with stabilized DC-lit filaments, the circuit guarantees an absolute black background and a virtually non-existent noise floor.
📐 THE SUBSTANCE OF TONE: ELITE COMPONENT SELECTION
Every passive component is selected following strict laboratory testing to perfect the overall frequency response:
• Resistors: A calibrated coupling of carbon composition Allen Bradley resistors (preserving linearity and timbral density) and high-precision Tantalum resistors engineered for ultra-low thermal noise.
• Capacitors: A shielded blend of premium Metallized Polypropylene, Paper-in-Oil (PIO), and Elna electrolytic capacitors, chosen to maintain a natural harmonic decay and a transparent midrange register.
• Mechanical Control Interface: Alps plastic film potentiometer and an ultra-precision Eizz rotary selector featuring gold-plated contacts, configured to safeguard perfect channel balancing and long-term performance consistency.
🛠 OFFICIAL TECHNICAL SPECIFICATIONS – REFERENCE PREAMPLIFIER
• Circuit Architecture: Single Triode Preamplifier featuring Anode Choke Inductive Loading
• Signal Tube: 6S45 (Ultra-high transconductance single triode)
• Rectifier Tube: Dedicated vacuum tube for high-voltage plate rectification
• Power Supply Module: Multi-stage CLCL / CR filtration network with isolated, stabilized DC-lit filaments
• Input Impedance: 25 kOhm (determined by the precision attenuation stage)
• Output Impedance: ~450 Ohm (an exceptionally low rating achieved via the high native transconductance of the 6S45 tube coupled to the inductive load)
• Max Output Voltage: > 40V RMS (Massive dynamic swing before saturation or clipping)
• Output Coupling: 4uF capacitive module optimized for downstream loads of 100kOhm
• Chassis & Construction: 100% Handcrafted 3D Point-to-Point air-wired circuit inside a non-magnetic chassis
⚖️ THE EVOLUTION OF SOUND: SYNERGY BETWEEN CRAFTSMANSHIP AND ARTIFICIAL INTELLIGENCE
"Transferring my reference system into a new listening environment—characterized by a smaller footprint and an asymmetrical geometry with a sloped ceiling—had severely compromised the delicate electroacoustic balance developed over the years. The midrange spectrum felt overly forward, and the physical impact of the Onken loading appeared partially blurred by room reflections.
After verifying in the field that common equalizers or traditional ground-connected RC shunt networks introduced more alterations than benefits—since they dissipate part of the signal energy to ground, causing micro-dynamic attenuation and a loss of tonal vitality—I chose to pioneer a new path.
Collaborating with the analytical computing power of Artificial Intelligence (Google AI), we modeled and simulated a geometric solution that does not attenuate the signal, but instead preserves and shapes its integrity. The process seamlessly merged the analog intuition of pen and paper with ultimate digital precision: the algorithm generated complex Python scripts, while Andy translated and refined the models using CAD software and specific design programs. Through this synergy between my musician’s sensibility and advanced algorithmic processing, a strictly in-series LCR (Inductance-Capacitance-Resistance) compensation network was born.
Unlike traditional passive filters, this system acts on the electrical phase to harmonize the acoustic phase response of the loudspeakers within the room, temporally realigning the midrange register with the submarine descent of the Onken bass, without any loss of gain or transparency.
The definitive test was performed on Roger Waters' holophonic masterpiece 'Amused to Death': the soundstage reconstruction achieved millimeter-level geometric precision, where details float in the surrounding space with three-dimensional realism. It is the ultimate confirmation: when the noble tube tradition marries the frontiers of modern computational technology, sound reproduction rediscovers its deepest truth."
🔊 Andy Roman Hi-Fi
Reference 300B Dual Mono System
"A pure Class A reference thermionic amplification architecture, engineered for the geometric and holographic reconstruction of the original acoustic event through extreme Point-to-Point craftsmanship."
📐 DESIGN PHILOSOPHY: TRUE DUAL MONO ARCHITECTURE
The system is developed according to the strict principles of absolute True Dual Mono design. The power supply section, signal paths, and filtration modules are symmetrically and independently structured for each channel within the same chassis. This radical electromechanical isolation completely eliminates crosstalk (interchannel diafonia), securing elite soundstage separation and a three-dimensional field where every source is focused with millimeter precision.
📐 HIGH-TRANSCONDUCTANCE SIGNAL ENGINEERING & DRIVING STAGE
• Triode Core: The power stage relies on the legendary 300B directly-heated triode, driven by the ultra-high transconductance 6S45 single triode (high-performance NOS selection).
• Inductive Loading (Anode Choke): In both the preamplifier stage and the power amp's driver section, traditional plate resistors are replaced by Hammond inductive chokes. This esoteric solution maintains a nearly horizontal dynamic load line, yielding massive dynamic headroom and linearity unattainable by conventional circuits.
• Galvanic Input Interface: The implementation of shielded Hammond input transformers ensures perfect galvanic isolation and a balanced, linear signal transfer entirely free from thermal coloration.
📐 POWER SUPPLY & PASSIVE ENERGY MANAGEMENT
• Vacuum Tube Rectification: The utilization of dedicated rectifier tubes guarantees a progressive turn-on voltage ramp for the plates, establishing total immunity against the high-frequency switching noise typical of solid-state components.
• Multi-Stage Filtration: A massive filtration architecture configured around a dual CL (Inductor-Capacitor) Pi-network, coupled to a dual RC stage. The negative bias voltage is further stabilized and isolated via a dedicated, independent CLC filter cell.
• Zero Noise Floor: Filament power entirely converted into stabilized Direct Current (DC) neutralizes residual AC ripple, allowing ambient micro-details to seamlessly emerge from a deep and sharp "acoustic blackness."
📐 THE SUBSTANCE OF TONE: ESOTERIC MATERIALS & GEOMETRIC WIRING
• Premium Component Selection: Acoustic synergy integrating Mundorf Paper-in-Oil (PIO) capacitors, Nichicon Muse cathode capacitors, Elna Cerafine, and high-velocity Polypropylene modules.
• Resistors: Targeted coupling of carbon composition Allen Bradley resistors (preserving timbral density and linearity) and high-precision wirewound resistors engineered for exceptional thermal stability.
• High-End Differentiated Wiring: Three-dimensional, handcrafted point-to-point layout employing a calculated combination of Solid Core, Multi-strand, and Litz conductors, geometrically optimized based on the current and frequency traveling through each specific circuit node.
• Mechanical Control: Alps plastic film potentiometer configured to safeguard flawless channel balancing and long-term performance consistency.
🛡️ OPERATIONAL SAFETY & STABILITY
A passive protection circuit, equipped with safety resistors and an isolation fuse on the ground path, preserves the integrity of the premium 300B triodes from any electrical anomaly or voltage surge, ensuring uncompromised long-term performance stability.
🛠 OFFICIAL TECHNICAL SPECIFICATIONS – REFERENCE 300B DUAL MONO POWER AMP
• Circuit Architecture: True Dual Mono (100% independent power supplies and signal paths per channel)
• Power Configuration: Single-Ended Pure Class A
• Power Tube: 300B directly-heated triode
• Driver Tube: 6S45 high-transconductance triode (NOS)
• Power Output: ~7 Watt RMS per channel
• Input Sensitivity: ~1V RMS (for maximum power displacement)
• Nominal Input Impedance: 100 kΩ
• Output Impedance: ~1.5 Ω (Damping Factor optimized for a natural, tight membrane control)
• Output Transformers: Ikarus Audio - Favero featuring high-magnetic-permeability "Double C" cores
• Negative Feedback (NFB): No NFB (Zero Negative Feedback) for ultimate transient linearity
• Load Impedance (Z): 5 kΩ nominal (6.5 kΩ reflected into an 8 Ohm load)
• Input Transformers: Hammond (Galvanic isolation and signal balancing)
• Anodic Supply: 340V - Vacuum Rectified via a dedicated rectifier tube
• Plate Filtration: Multi-stage architecture consisting of dual CL Pi-networks + dual RC modules
• Bias Management: Stabilized Negative Bias voltage featuring an independent CLC filter cell
• Construction: 100% Handcrafted tridimensional 3D Point-to-Point air-wired circuit
"To Gianfranco Pellas, master and friend. Thank you for teaching me to seek the truth in sound."
EL84 Push-Pull – Purity and Control
This power amplifier represents the perfect balance between tube sweetness and crystalline precision. Designed for those seeking a refined listening experience, the heart of this project beats around a quartet of EL84 tubes in triode configuration, a choice made to maximize linearity and harmonic richness.
Architecture and Circuitry
The preamplification and phase inverter section is powered by the historic 6SN7, iconic tubes known for their natural tone. In line with the Andy Roman philosophy, the circuit is strictly No NFB (No Negative Feedback): no global feedback is applied, allowing the signal to express itself with its full original dynamics.
High-End Components
The quality of an amplifier lies in the details. We have selected only the finest components:
Audio Note Output Transformers: The absolute benchmark for bandwidth and micro-detail.
Favero Power Transformer: Oversized to ensure maximum stability and silent operation.
Vintage & Modern Core: Allen Bradley resistors for that inimitable warmth, Wima capacitors, and the legendary Black Gate for lightning-fast transient response.
Control: Alps RK27 (Blue Velvet) potentiometer for smooth and precise volume adjustment.
Handcrafted "Point-to-Point" Construction
Like every one of our creations, the wiring is entirely hand-done point-to-point. The assembly is performed on a custom plexiglass board, which provides superior structural rigidity while isolating components to reduce mechanical interference.
Power Management
The power supply is meticulously engineered to eliminate background noise:
Fast Diodes for precise rectification without switching noise.
Power tubes (EL84) supplied in AC to preserve their vibrant character.
Preamp section (6SN7) supplied in DC to guarantee absolute silence during the most delicate musical passages.
A power amplifier that doesn't just play music—it stages it.
🛠 OFFICIAL TECHNICAL SPECIFICATIONS – EL84 PUSH-PULL POWER AMPLIFIER
Feature
Official Technical Details
Architecture
Triode Push-Pull (EL84 triode-strapped)
Power Tubes
Matched quad of EL84
Preamp / Phase Inverter
6SN7 (dual triode)
Feedback (NFB)
No NFB (Zero Negative Feedback)
Output Transformers
Audio Note (Benchmark for bandwidth and detail)
Power Transformer
Favero (Oversized for high stability)
Load Impedance (Z)
10 kΩ (Optimized for maximum linearity and low distortion)
Speaker Outputs
4 Ohm / 8 Ohm
Input
Alps Blue Velvet 100 kΩ potentiometer
Power Supply
Fast diodes; Preamp section in DC (Zero Noise); Power section in AC
Components
Black Gate, Wima, Allen Bradley Resistors
Construction
Point-to-Point wiring on an insulating Plexiglass base
Andy Roman Hi-Fi
Reference 2-Way "Onken-Jensen" Loudspeakers
"A high-efficiency two-way loudspeaker system, engineered as a symbiotic union between the purity of direct radiation designs and the linear precision of large-scale studio monitors. Developed to guarantee absolute transparency of the audio signal and a presentation entirely free from artifacts."
📐 ACOUSTIC ENGINEERING: THE INTEGRATED JENSEN-ONKEN LOADING
• Low-Frequency Section: Featuring a massive 15-inch Eminence transducer, deeply modified in-house to optimize and recalibrate its native electroacoustic parameters (Thiele & Small parameters). The proprietary Jensen-Onken loading guarantees a rigorous, tight low-end extension characterized by extraordinary transient velocity, eliminating the overhang and artificial resonances common in traditional ports.
• High-Frequency Section: The upper register is driven by a Ciare compression driver equipped with a high-flux Neodymium magnetic circuit, coupled to a calculated exponential horn. This configuration ensures controlled angular dispersion, minimal intermodulation distortion, and surgical resolution of micro-details within the signal.
🎛️ CORE OF THE SYSTEM: THE PROPRIETARY CROSSOVER NETWORK
The integrity of the acoustic soundstage relies upon a sophisticated 3rd-order partition filter (18 dB/octave). Far from a common passive divider, it is a complex compensation network engineered for:
• Phase and Time Coherence: Neutralizing phase rotation at the acoustic crossover point, securing a perfect temporal alignment between the woofer and driver emissions.
• Holographic Reconstruction: Preserving the three-dimensional development of the soundstage in height, width, and depth. The physical boundaries of the loudspeakers dissolve into the room, delivering a geometrically accurate focus of individual elements within the sonic field.
🛠 Construction & Materials
• Enclosure: Built entirely from premium, cross-laminated Swedish Birch Plywood, selected for its superior mechanical damping coefficient and structural rigidity. Internal resonances and standing waves are geometrically neutralized, keeping the tone unpolluted by unwanted colorations.
• Electroacoustic Synergy: Thanks to an elite sensitivity rating and a linear impedance module, this system represents the ideal coupling to maximize the harmonic purity, micro-dynamics, and tonal refinement of Single-Ended Pure Class A amplifiers, such as our Reference 300B platform.
🛠 OFFICIAL TECHNICAL SPECIFICATIONS – REFERENCE 2-WAY LOUDSPEAKERS
• System Typology: 2-Way high-efficiency direct-radiation monitor loudspeaker
• Acoustic Alignment: Calculated lower Jensen-Onken loading
• Low Transducer: 15" Eminence Woofer (Electroacoustic parameters custom-modified by Andy Roman)
• High Transder: Ciare Neodymium compression driver with dedicated Exponential Horn
• Crossover Architecture: 3rd-order filter (18 dB/octave slope), phase-coherent with impedance compensation networks
• Nominal Sensitivity: ~100-102 dB SPL (Optimized for Single-Ended vacuum tube sections and elite low-power amplification)
• Enclosure Construction: Integral high-density Swedish Birch Plywood chassis
• Sonic Profile: Holographic acoustic space reconstruction, zero phase rotation, and linear transient dynamics
Andy Roman Hi-Fi "Master Series" Standmount Monitors
"A compact standmount loudspeaker system engineered to redefine the boundaries of resolution and linearity within its class. An elite platform where the transducer excellence of Dynaudio is seamlessly integrated into a total inertial damping enclosure, explicitly designed to eliminate structural resonances."
📐 TRANSDUCER EXCELLENCE
• Dynaudio MW170 Mid-Woofer: A reference transducer featuring a proprietary MSP (Magnesium Silicate Polymer) cone and an oversized aluminum voice coil. It guarantees linear displacement and an authoritative low-end response, paired with a midrange register characterized by absolute transparency and zero thermal compression.
• Dynaudio D260 Esotec Tweeter: One of the most acclaimed soft-dome transducers in high-fidelity history. It delivers optimal angular dispersion, ultra-low harmonic distortion, and microscopic resolution of fine detail, entirely preventing acoustic fatigue.
📐 ENCLOSURE ENGINEERING: HIGH-DENSITY SANDWICH ARCHITECTURE GROUNDED IN ACOUSTIC INERTIA
To allow the transducers to operate completely unpolluted by cabinet-wall colorations, the enclosure deploys advanced mechanical solutions:
• Multi-Layer Composite Structure: A sandwich architecture coupling high-density MDF with external sections of selected solid Oak, maximizing rigidity while scattering the materials' resonance frequencies.
• Lead Mechanical Damping: Enclosure interior walls are fully lined with heavy-gauge Lead sheeting. This configuration drastically increases total cabinet mass and maximizes kinetic inertia, dissipating vibrational energy and ensuring the complete suppression of standing waves. The loudspeaker boundaries dissolve into the room, leaving the integrity of the acoustic event intact.
🎛️ NETWORK COHERENCE: CROSSOVER ARCHITECTURE
The network partition is calibrated to track the natural frequency response of individual transducers while safeguarding phase integrity:
• Low-Pass Section (Woofer): 1st-order filter featuring a gentle 6 dB/octave slope, configured to secure minimal phase rotation and an exceptionally smooth, progressive transition.
• High-Pass Section (Tweeter): 3rd-order filter featuring an 18 dB/octave slope, calculated to guarantee proper thermo-mechanical damping at the acoustic crossover point and surgical accuracy in soundstage reconstruction.
🛠 OFFICIAL TECHNICAL SPECIFICATIONS – "MASTER SERIES" MONITOR
• System Typology: 2-Way high-resolution standmount monitor loudspeaker
• Low-Mid Transducer: Dynaudio MW170 (MSP cone, aluminum voice coil)
• High Transducer: Dynaudio D260 Esotec (Premium treated soft-dome)
• Enclosure Construction: Composite Sandwich architecture (High-density MDF + Solid Oak)
• Vibration Dissipation: Complete internal lining via high-mass Lead sheeting (Total acoustic inertia)
• Crossover Low Channel: Proprietary 1st-order filter for minimal phase rotation
• Crossover High Channel: Proprietary 3rd-order filter for maximum crossover coherence and micro-detail focus
• Nominal Sensitivity: ~86-88 dB SPL (Native specification characteristic of elite Dynaudio alignment parameters)
• Electroacoustic Profile: Absolute elimination of parasitic vibrations and strict timbral accuracy of the signal
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