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Description
The Feliks Audio Envy Susvara Edition is the most powerful Feliks Audio headphone amplifier to date, purpose-built for the most demanding headphones in the world. Based on the flagship Envy platform, this Class-A, single-ended, transformer-coupled tube amplifier was developed around one of the most celebrated pairings in high-end headphone audio: Feliks Envy and the HIFIMAN Susvara.
The original Envy was already known for its ability to bring power, scale, tone, and refinement to summit-fi headphone systems. The Susvara Edition pushes that formula further with up to 9 watts of output power, new gain settings, premium Stradi S300B power tubes, amorphous-core output transformers, and upgraded signal-critical components inspired by Feliks Audio’s 25th Anniversary Edition. The result is an amplifier built not only for Susvara, but for any headphone that needs serious drive, control, and musical authority.
Designed for Susvara, Built for Any Demanding Headphone
The HIFIMAN Susvara has a reputation for being one of the most demanding headphones ever made. It rewards amplifiers that can deliver real current, voltage swing, dynamic headroom, and control without flattening the character of the music. That is exactly where the Envy Susvara Edition is focused.
Feliks Audio redesigned the gain structure with Low, High, and Susvara settings, with the dedicated Susvara mode delivering up to a 12% increase in power output compared to the Envy Performance. In practice, the Envy Susvara Edition outputs up to 9 watts of Class-A power, giving it the headroom to handle difficult planar magnetic headphones while still preserving the tone, dimensionality, and natural flow that make 300B tube amplifiers special.
More Than a Power Upgrade
The Envy Susvara Edition is not simply a louder Envy. Feliks Audio brought it closer to the technical level of the Envy 25th Anniversary Edition with upgraded output transformers, improved internal wiring, enhanced interference handling, and higher-grade signal components throughout the circuit.
That matters because high-end headphone amplification is not just about raw wattage. The best amplifiers control difficult headphones while preserving low-level detail, texture, dynamics, and spatial information. The Susvara Edition is designed to deliver that combination: more authority when the music demands it, and more finesse when the recording calls for restraint.
Amorphous-Core Output Transformers
One of the most important upgrades in the Envy Susvara Edition is the use of custom amorphous-core output transformers. These transformers are designed to provide ultra-low noise, strong dynamics, and extended frequency response, giving the amplifier the bandwidth and control expected from a true endgame headphone amp.
For listeners, that translates into more effortless swings in volume, a quieter background, stronger bass grip, and a more open sense of space. It is the kind of upgrade that supports both technical performance and musical realism, especially with headphones capable of revealing every change upstream.
Premium Stradi S300B Tubes
The Envy Susvara Edition comes equipped with carefully matched Stradi S300B power tubes, chosen for their precise, detailed, and airy presentation. A great 300B amplifier depends heavily on the quality of its tubes, and Feliks Audio includes a tube set that is ready for serious listening right out of the box.
The amplifier is also compatible with standard 300B power tubes using a 5V filament voltage, giving listeners room to shape the sound over time through tube rolling. That means the Susvara Edition can serve as both an endgame amplifier out of the box and a long-term platform for listeners who enjoy fine-tuning their system.
Signal-Critical Component Upgrades
Beyond the tubes and transformers, Feliks Audio upgraded several signal-critical parts of the Envy Susvara Edition, including capacitors, resistors, and internal wiring. High-precision components from brands such as Jantzen, Vishay, Nichicon, and Dale are used to improve signal clarity, repeatability, and overall circuit performance.
Feliks also made additional refinements to tube parameter stabilization, tube-related failure protection, and the preamp output stage. The preamp section has been modified to reduce noise and better handle higher signal levels, making the Envy Susvara Edition a stronger centerpiece for both headphone and two-channel systems.
Handcrafted in Poland
The Envy Susvara Edition is handcrafted by Feliks Audio in Lubliniec, Poland, with the kind of build quality expected from the brand’s flagship line. Its solid Wenge wood finish gives the amplifier a warm, architectural presence that matches its sonic character. Custom wood finishes may also be available by request.
Visually, the Susvara Edition shares a clear family resemblance with the Envy Anniversary Edition, but replaces the piano-black finish with solid wood for a more classic Feliks Audio identity. It is substantial, elegant, and unmistakably built for a system where the amplifier is meant to be seen as much as heard.
Key Features
Flagship Class-A, single-ended, transformer-coupled tube headphone amplifier
Most powerful Feliks Audio headphone amplifier to date
Designed as the ultimate pairing for HIFIMAN Susvara and other demanding headphones
Up to 9 watts of maximum output power
Low, High, and Susvara gain settings
Susvara gain mode delivers up to a 12% power increase over Envy Performance
Carefully matched premium Stradi S300B power tubes included
PsVane CV-181 Mk. 2 driver tubes included
Custom amorphous-core output transformers for low noise, dynamics, and extension
Signal-critical component upgrades inspired by the Envy 25th Anniversary Edition
High-precision components from Jantzen, Vishay, Nichicon, and Dale
Improved internal wiring and interference handling
Modified preamp output stage for reduced noise and higher signal levels
6.3mm and 4-pin XLR headphone outputs
RCA and XLR inputs
RCA and XLR preamp outputs
Solid Wenge wood finish by default
Handcrafted in Lubliniec, Poland
Technical Specs
Product Type
Class-A, single-ended, transformer-coupled tube headphone amplifier and preamp
Power Tubes
Stradi S300B
Driver Tubes
PsVane CV-181 Mk. 2 / 6SN7
Maximum Output Power
9 W
Inputs
2 x unbalanced RCA inputs, 1 x balanced XLR input
Input Sensitivity
1 V RMS
Input Impedance
100 kΩ for RCA inputs, 10 kΩ for XLR input
Preamp Outputs
1 x pair RCA, 1 x pair XLR
Preamp Output Level
Maximum 5 V RMS at 600 Ω output impedance and THD < 0.5%
Headphone Outputs
6.3mm and 4-pin XLR
Amplifier Impedance
Low: 3.8Ω at 32Ω load; High: 20Ω at 600Ω load; Susvara: 22Ω at 600Ω load
Frequency Response
7 Hz to 100 kHz +/- 3 dB; 15 Hz to 43 kHz +/- 1 dB
AC Voltage
115 V or 230 V, 50 / 60 Hz
Power Consumption
110 VA
Finish
Wenge solid wood by default
Weight
15.1 kg
Dimensions
35 x 33 x 18.5 cm
What’s in the Box
Feliks Audio Envy Susvara Edition headphone amplifier
2 Stradi S300B tubes
2 PsVane CV-181 Mk. 2 tubes
AC power cord
User manual
Warranty card
The original Envy was already known for its ability to bring power, scale, tone, and refinement to summit-fi headphone systems. The Susvara Edition pushes that formula further with up to 9 watts of output power, new gain settings, premium Stradi S300B power tubes, amorphous-core output transformers, and upgraded signal-critical components inspired by Feliks Audio’s 25th Anniversary Edition. The result is an amplifier built not only for Susvara, but for any headphone that needs serious drive, control, and musical authority.
Designed for Susvara, Built for Any Demanding Headphone
The HIFIMAN Susvara has a reputation for being one of the most demanding headphones ever made. It rewards amplifiers that can deliver real current, voltage swing, dynamic headroom, and control without flattening the character of the music. That is exactly where the Envy Susvara Edition is focused.
Feliks Audio redesigned the gain structure with Low, High, and Susvara settings, with the dedicated Susvara mode delivering up to a 12% increase in power output compared to the Envy Performance. In practice, the Envy Susvara Edition outputs up to 9 watts of Class-A power, giving it the headroom to handle difficult planar magnetic headphones while still preserving the tone, dimensionality, and natural flow that make 300B tube amplifiers special.
More Than a Power Upgrade
The Envy Susvara Edition is not simply a louder Envy. Feliks Audio brought it closer to the technical level of the Envy 25th Anniversary Edition with upgraded output transformers, improved internal wiring, enhanced interference handling, and higher-grade signal components throughout the circuit.
That matters because high-end headphone amplification is not just about raw wattage. The best amplifiers control difficult headphones while preserving low-level detail, texture, dynamics, and spatial information. The Susvara Edition is designed to deliver that combination: more authority when the music demands it, and more finesse when the recording calls for restraint.
Amorphous-Core Output Transformers
One of the most important upgrades in the Envy Susvara Edition is the use of custom amorphous-core output transformers. These transformers are designed to provide ultra-low noise, strong dynamics, and extended frequency response, giving the amplifier the bandwidth and control expected from a true endgame headphone amp.
For listeners, that translates into more effortless swings in volume, a quieter background, stronger bass grip, and a more open sense of space. It is the kind of upgrade that supports both technical performance and musical realism, especially with headphones capable of revealing every change upstream.
Premium Stradi S300B Tubes
The Envy Susvara Edition comes equipped with carefully matched Stradi S300B power tubes, chosen for their precise, detailed, and airy presentation. A great 300B amplifier depends heavily on the quality of its tubes, and Feliks Audio includes a tube set that is ready for serious listening right out of the box.
The amplifier is also compatible with standard 300B power tubes using a 5V filament voltage, giving listeners room to shape the sound over time through tube rolling. That means the Susvara Edition can serve as both an endgame amplifier out of the box and a long-term platform for listeners who enjoy fine-tuning their system.
Signal-Critical Component Upgrades
Beyond the tubes and transformers, Feliks Audio upgraded several signal-critical parts of the Envy Susvara Edition, including capacitors, resistors, and internal wiring. High-precision components from brands such as Jantzen, Vishay, Nichicon, and Dale are used to improve signal clarity, repeatability, and overall circuit performance.
Feliks also made additional refinements to tube parameter stabilization, tube-related failure protection, and the preamp output stage. The preamp section has been modified to reduce noise and better handle higher signal levels, making the Envy Susvara Edition a stronger centerpiece for both headphone and two-channel systems.
Handcrafted in Poland
The Envy Susvara Edition is handcrafted by Feliks Audio in Lubliniec, Poland, with the kind of build quality expected from the brand’s flagship line. Its solid Wenge wood finish gives the amplifier a warm, architectural presence that matches its sonic character. Custom wood finishes may also be available by request.
Visually, the Susvara Edition shares a clear family resemblance with the Envy Anniversary Edition, but replaces the piano-black finish with solid wood for a more classic Feliks Audio identity. It is substantial, elegant, and unmistakably built for a system where the amplifier is meant to be seen as much as heard.
Key Features
Flagship Class-A, single-ended, transformer-coupled tube headphone amplifier
Most powerful Feliks Audio headphone amplifier to date
Designed as the ultimate pairing for HIFIMAN Susvara and other demanding headphones
Up to 9 watts of maximum output power
Low, High, and Susvara gain settings
Susvara gain mode delivers up to a 12% power increase over Envy Performance
Carefully matched premium Stradi S300B power tubes included
PsVane CV-181 Mk. 2 driver tubes included
Custom amorphous-core output transformers for low noise, dynamics, and extension
Signal-critical component upgrades inspired by the Envy 25th Anniversary Edition
High-precision components from Jantzen, Vishay, Nichicon, and Dale
Improved internal wiring and interference handling
Modified preamp output stage for reduced noise and higher signal levels
6.3mm and 4-pin XLR headphone outputs
RCA and XLR inputs
RCA and XLR preamp outputs
Solid Wenge wood finish by default
Handcrafted in Lubliniec, Poland
Technical Specs
Product Type
Class-A, single-ended, transformer-coupled tube headphone amplifier and preamp
Power Tubes
Stradi S300B
Driver Tubes
PsVane CV-181 Mk. 2 / 6SN7
Maximum Output Power
9 W
Inputs
2 x unbalanced RCA inputs, 1 x balanced XLR input
Input Sensitivity
1 V RMS
Input Impedance
100 kΩ for RCA inputs, 10 kΩ for XLR input
Preamp Outputs
1 x pair RCA, 1 x pair XLR
Preamp Output Level
Maximum 5 V RMS at 600 Ω output impedance and THD < 0.5%
Headphone Outputs
6.3mm and 4-pin XLR
Amplifier Impedance
Low: 3.8Ω at 32Ω load; High: 20Ω at 600Ω load; Susvara: 22Ω at 600Ω load
Frequency Response
7 Hz to 100 kHz +/- 3 dB; 15 Hz to 43 kHz +/- 1 dB
AC Voltage
115 V or 230 V, 50 / 60 Hz
Power Consumption
110 VA
Finish
Wenge solid wood by default
Weight
15.1 kg
Dimensions
35 x 33 x 18.5 cm
What’s in the Box
Feliks Audio Envy Susvara Edition headphone amplifier
2 Stradi S300B tubes
2 PsVane CV-181 Mk. 2 tubes
AC power cord
User manual
Warranty card
SKU: FLA-ENVY-SUS
