The Spheris preamplifier has now been in production for 20 years across 3 generations and has earned the reputation of being one of the finest tube preamplifiers ever built.

With the introduction of the fourth generation in 2024, the new Spheris Evo – Linestage was born and this has been further developed, refined and aimed at audiophiles who accept nothing less than the best as the new reference standard for vacuum tube linestage preamplification. It is a marvel of engineering with its unique tube circuit design and construction. This preamp sets new standards for natural music reproduction with its exceptionally wide bandwidth, ultra-low distortion, colorful superior dynamic range and an airy three-dimensional holographic soundstage.

The Spheris AC~ external regenerator delivers stable, regulated and purified AC power, regardless of the quality of the incoming AC line. This power supply ensures a lower noise floor, more liquidity, better 3D spatial imaging, greater focus, richer colours and less glare and haze.

F e a t u r e s  &  D e s i g n

2 Chassis full-featured Class A – triode/pentode single-ended & true balanced vacuum- tube stereo preamplifier

Unique new pure vacuum tube-circuit design with single gain stage and incorporates only one coupling capacitor at its output stage

Limited production

Vacuum Tubes

The choice of signal and power tubes have a significant influence on the sound and hence on the inspiration and joy of listening. This is not only the decision between good and bad tubes but finally the interaction of the different types of tubes and their combination that are used in the various Ayon amplifiers.

• Special tubes for stereo line-amplification ( tube life min. 10000 hrs )

Signal Path

We believe that the simplest circuits work best together with the shortest signal path. The shorter the signal path is, the less possibility of sonic degradation from various sources, including the wire itself. Even on the circuit boards, the copper traces are kept to a very minimum length. The completely redesigned circuit board provides a more straightforward and direct approach to the signal paths.

• Ultra short signal path ●  Simplest direct circuit path for purest musical sound and high reliability
• Very low output impedance to drive any tube or solid state power amp
• No solid state devices in the signal path ●  High current and low impedance design that operates tubes in the best areas their curves                                                                                                                                     ●  Minimal discrete wiring for optimum signal propagation
• No followers or buffers in the signal path
• High quality parts throughout
• 0dB negative feedback (of any kind )
• All line inputs – impedance > 1MOhm
• Selector switch engages relays located near RCA jacks to switch all inputs
• Special alloy solder used for the best electrical connection

AC~ReGenerator – Power Supply

The power supplies have been further refined with new components and enhanced AC line noise filtration. Separate power transformers, chokes and filters provide total isolation between the input and output stages which makes this a pure power source. We also use electrolytic capacitors with much larger storage capacity to make up for the loss in filtering when using resistors in lieu of inductors.

• Tube rectified power supply with built in AC ~ Regenerator
• Regenerated AC power and low distortion sine wave
• Superior noise reduction
• Low noise – power transformer
• Power transformer is excellent damped and RFI/EMI ultra-shielded
• Innovative power supply provides a high speed energy delivery on transients
• Triple choke filtered power supply for power tubes
• Separate and isolated power supplies over each stage of amplification ●  Regulated DC filament supplies with soft-start power up for extended tube life
• ●  AC power line filter to avoid noise and hash from entering into the unit.
• ●  High capacitance energy storage.
• ●  Frequency meter (60Hz)

Dual Grounding System

The modification of the grounding topology leads to increased rejection of noise from the power supply and other areas. The dual grounding topology used in all of our amplifiers is quite unique to the whole hi-end tube amplification industry. Such extensive topology provides for quieter backdrop for which the music can unfold in its entirety. It further establishes the quick and controlled bass response and the full-bodied expression of the high frequency. The ground leg of the signal has not been neglected and given meticulous attention in its implementation. The importance of proper grounding cannot be over emphasized.

• Ground switch
• Central one-point star earth grounding
• Dual grounding system (switchable)

Components

The type of parts used therefore must have a synergistic relationship to the circuit they are placed in. It is this relationship of which type of part to use where, that ranks our products apart from the mass.

• Ultra selected, absolute best quality passive components used in all applications
• High speed & high quality audiophile grade coupling capacitors
• Special tube sockets with beryllium- copper spring pins, custom made by Ayon
• WBT / High quality – RCA input jack
• Neutrik/Swiss – XLR chassis connectors
• Special isolated – internal wiring
• Premium internal signal cable uses ultra pure, soft annealed copper and super low loss

insulation

• Gold-plated industrial grade PCB
• Elma/Swiss – Input selector switches
• VTC – “volume transformer control”, 4 channels / 42 position – electronic-relay system,

custom made by ayon

• This stepped volume control system has a channel balance within +/- 0.05dB.
• Best sounding precision special resistors 0,5% are used everywhere, best

resolution and lowest noise.

• Rifa – Long life capacitors

Mechanical Construction

The high-grade aluminum chassis impart a richer, more lustrous tonality with a cleaner background and less hash and grain. All brushed anodized anti-vibration-resonance and non-magnetic chassis’s are fully hand assembled to insure the highest level of craftsmanship.

• Improved heat ventilation chassis
• Backlit front panel displays indicate level attenuation & input selection
• The aluminium feet are resonance absorbing types
• All front & rear panel descriptions are engraved
• Ground switch
• Volume & Mute function – RC
• Metal remote commander
• Chassis finish: black / chrome