Sheet 02 of 05
Signal chain
A flagship headphone only shows what it can do when the electronics in front of it can deliver what it asks for. Start with the calculator, then choose the parts.
- Headphones modelled
- 25
- Components indexed
- 31
- Levels
- 100, 110 and 120 dB
- Method
- Published output into rated loads
Synergy calculator
Choose a headphone and a listening level. It works out the power, voltage and current required, then ranks every amplifier and DAC with a headphone output in the index by how much headroom it leaves. Amplifiers whose makers publish no output rating are listed below the calculator but not ranked.
- Power
- 501mW
- Voltage
- 5.48V rms
- Current
- 91.4mA
Susvara is rated 83 dB/mW into 60 ohms. 110 dB, peaks in dynamic music.
Amplifiers in the index, by headroom
ampsandsound Bigger Ben (Rev 3, 2026): Single-ended Class A, zero feedback, tube (6SL7 input; output tubes 6L6GC, EL34, KT66, KT77, KT88, 6550 or KT90), cathode bias; input transformers and custom output transformers with 8/16/32/100/300 ohm headphone taps plus an 8 ohm speaker tap. $6,400
Drive map at 110 dB. Click a point to select it.
Points up and to the right need more from an amplifier. The shaded region is what the highlighted amplifier can deliver, estimated from its published output into rated loads, so anything inside it is covered. Open the Susvara
Table view
| Headphone | dB/mW | Ohms | V | mA |
|---|---|---|---|---|
| Meze Audio ARTA | 98 | 225 | 1.89 | 8.39 |
| HIFIMAN Susvara | 83 | 60 | 5.48 | 91.4 |
| Abyss AB-1266 Phi TC | 88 | 50 | 2.82 | 56.3 |
| Yamaha YH-5000SE | 98 | 34 | 0.73 | 21.6 |
| Focal Utopia (2022) | 104 | 80 | 0.56 | 7.05 |
| Abyss Diana TC Signature | 90 | 72 | 2.68 | 37.3 |
| Audeze LCD-5s | 90 | 35 | 1.87 | 53.5 |
| Dan Clark Audio Stealth | 90 | 23 | 1.52 | 65.9 |
| Dan Clark Audio Expanse | 90 | 26 | 1.61 | 62.0 |
| Final D8000 Pro Edition | 98 | 60 | 0.98 | 16.3 |
| Meze Audio Elite | 101 | 32 | 0.50 | 15.8 |
| ZMF Caldera | 95 | 60 | 1.38 | 23.0 |
| Focal Stellia | 106 | 35 | 0.30 | 8.47 |
| Meze Audio Empyrean II | 90 | 32 | 1.79 | 55.9 |
| Grado Signature HP100 SE | 117 | 38 | 0.09 | 2.29 |
| Sennheiser HD 820 | 97.8 | 300 | 2.23 | 7.44 |
| Audio-Technica ATH-ADX5000 | 100 | 420 | 2.05 | 4.88 |
| Sennheiser HD 800 S | 96.8 | 300 | 2.50 | 8.35 |
| HIFIMAN HE1000se | 96 | 35 | 0.94 | 26.8 |
| Audeze MM-520 | 102 | 18 | 0.34 | 18.7 |
| Focal Clear MG | 104 | 55 | 0.47 | 8.51 |
| Rosson Audio Design RAD-0 | 98 | 29 | 0.68 | 23.4 |
| ZMF Vérité Closed | 99 | 300 | 1.94 | 6.48 |
| Sony MDR-Z1R | 100 | 64 | 0.80 | 12.5 |
| Fostex TH900mk2 | 100 | 25 | 0.50 | 20.0 |
Clean power
Regenerators and conditioners that feed everything downstream from a quieter supply.
- PS AudioPowerPlant 12AC regenerator: rebuilds the AC with amplifier-style active stages, 1,200 VA output, 8 US outlets, 15 A input, adjustable output voltage and MultiWave waveform selectionRegenerated output is 100% rebuilt AC, with a front-panel THD meter and 95 to 145 VAC input range in the US version.AC regenerator: rebuilds the AC with amplifier-style active stages, 1,200 VA output, 8 US outlets, 15 A input, adjustable output voltage and MultiWave waveform selectionMade in USA$5,999
- Niagara 7000Patented dielectric-biased symmetrical isolation transformers (2 source-component banks), Level-X ultra-linear noise dissipation, Transient Power Correction (90 A peak); 8 source and 4 high-current outlets; 20 A inputNon-sacrificial surge protection is rated to withstand repeated surges up to 6,000 V / 3,000 A.Patented dielectric-biased symmetrical isolation transformers (2 source-component banks), Level-X ultra-linear noise dissipation, Transient Power Correction (90 A peak); 8 source and 4 high-current outlets; 20 A input$12,500
- Torus PowerRM 20Toroidal isolation transformer (single 2,400 VA toroid) with series-mode surge suppression; 120 V at 20 A; 10 outlets; IEC 20 A inletOutlets are Hubbell medical-grade types, and the unit has a 20 A circuit breaker as its power switch.Toroidal isolation transformer (single 2,400 VA toroid) with series-mode surge suppression; 120 V at 20 A; 10 outlets; IEC 20 A inletBlack or silver faceplate; 3U chassis, 19 x 16.5 x 6.3 in$4,999
- Everest-XPassive power distributor with six isolation zones; patented NIC and QR/BB, plus HARP, GPNR and CMode filtering; 8 NEMA 5-20R outlets; 30 A input; 40,000 A transient protectionShunyata states its products are built by hand at its factory in Poulsbo, Washington.Passive power distributor with six isolation zones; patented NIC and QR/BB, plus HARP, GPNR and CMode filtering; 8 NEMA 5-20R outlets; 30 A input; 40,000 A transient protectionAluminium and steel chassis with anodised aluminium faceplate; tower (16 kg) or shelf (12.7 kg) form factorMade in USAPrice on request
Conversion
Digital to analogue, built several ways: discrete resistor ladders, programmed FPGAs, dCS's Ring DAC and delta-sigma chips.
- Holo AudioMay DAC (KTE)Dual-mono, dual-chassis with external power supply; discrete resistor-network DAC modules with linear compensation; NOS plus three oversampling modesAn additional digitally controlled R-2R network compensates resistor tolerance in the main ladder, which Holo says reaches 0.00005% accuracy.Discrete R-2R resistor ladder with linear compensation (no DAC chip), 1536 kHz PCM, DSD1024 (native)Dual-chassis; KTE adds pure OCC silver wiring and hand-selected DAC modules (finish/material not published)Made in China$6,098
- Discrete DACTwo Prime DAC modules, fully balanced; modular input cards (Pro USB, Pro ISL, renderer); Femto clock; separate Discrete Power SupplyMSB says the analog output is low impedance and drives amplification directly without a buffer stage.Fully balanced, ultra-high precision discrete ladder DAC (Prime DAC module), 768 kHz PCM, DSD512 (8x DSD, Pro USB module)CNC unibody aluminium chassis on the power supply; LED display in a shielded CNC pocket; California craftedMade in USAPrice on request
- M11 Series II R-2RFully balanced XLR and RCA outputs; MDx digital processor platform; optional network and I2S cards; 8 ps jitter at 48 kHz (maker spec)Bricasti says the ladder DAC circuit is derived from its flagship M21 and builds on M1 Series II power supply technology.20-bit R-2R ladder DAC, 384 kHz PCM, DSD256 (native and DoP, USB)Classic (black), Argento (silver) or real Platinum finishMade in USA$12,500
- DAVEDesktop DAC, preamp and headphone amplifier; 4x BNC coax, AES, 2x Toslink, USB; balanced XLR, RCA and 6.35 mm headphone outputsChord says DAVE's FPGA runs over a million lines of code and applies a 164,000-tap filter.FPGA DAC (Spartan 6 FPGA, 164,000-tap filter; no off-the-shelf DAC chip), 768 kHz PCM, DSD512 (native and DoP)Solid aluminium chassis, black or silverMade in UK$14,900
- dCSBartok APEX DAC / Headphone AmplifierUpsampling network DAC with Class A headphone amplifier; DXD upsampling standard with optional DSD upsampling; separate power supplies for DAC and headphone amp; internal master clockThe APEX revision reworked the Ring DAC board with a new analog output stage built on compound-pair transistors.Ring DAC (APEX): dCS proprietary discrete multi-bit topology on a network of FPGAs, not a ladder DAC, no off-the-shelf DAC chip, 384 kHz PCM, DSD128 (DoP)Aerospace-grade machined aluminium chassis with internal acoustic damping panels, black or silverMade in UK$24,100
- DAC3 HGCFour balanced 32-bit converter channels summed per balanced output (4:1 summation); Hybrid Gain Control; UltraLock3 jitter attenuation; 32-bit DSP with 3.5 dB headroomThe ES9028PRO is an 8-channel converter, and Benchmark sums four of its channels in the analog domain for each output channel to cut noise by 6 dB.Delta-sigma (ESS ES9028PRO, four channels summed per output), 192 kHz PCM, DSD64 (DoP 1.1)Black or silver faceplate, half-rack width, 1 RUMade in USA$2,399
- N-05XENetwork player, DAC and preamp with dual-mono parallel single-ended headphone amplifier (4-pin XLR and 6.3 mm); separate FPGA algorithms for PCM and DSDEsoteric says the XE revision redesigned the resistor network at the first stage of the analog domain.Master Sound Discrete DAC G2: FPGA-based multi-level delta-sigma with discrete components, 768 kHz PCM, DSD512 (22.5 MHz native)Semi-floating top panel, laser-cut chassis slits, solid aluminium volume knob; silver or blackMade in Japan$13,000
- PS AudioPMG Signature 512 DACPureStream DSD512 engine upsamples every input to 8x DSD, then SpectraWave 64-tap sequencer, then fully balanced direct-coupled Class A analog output stage; galvanically isolated inputs; built-in streamerPS Audio states the design is a departure from PCM-based architectures and from off-the-shelf chip solutions, with SINAD better than -100 dB.PureStream DSD512 (proprietary, all inputs converted to 8x DSD; no off-the-shelf DAC chip), 768 kHz PCM, DSD512Black or silver$8,999
Valve amplification
Triodes, output transformers and point-to-point wiring, for the headphones that reward them.
Woo AudioWA33 (2nd generation)Fully balanced, push-pull, Class A, transformer-coupled, point-to-point wiring; 4x 6C45 drivers, 4x 2A3 power tubes, 5U4G rectifier; self-biasingThe 2nd generation adds a direct-drive current output (TR mode, 3.3 A) for True Ribbon headphones alongside the standard HP mode.10 W into 32 ohmsAnodized aluminium chassis (black or silver), PTFE tube socketsMade in USAfrom $9,999- Woo AudioWA5-LE (2nd generation)Single-ended triode, Class A, transformer-coupled, point-to-point wiring; 2x 300B power tubes, 2x 6SN7 drivers, 2x 5U4G rectifiers; pseudo-dual power supply, two-chassis designDedicated headphone version of the WA5; the amplifier and power supply sit in separate chassis of 35 lb each.Single-ended triode, Class A, transformer-coupled, point-to-point wiring; 2x 300B power tubes, 2x 6SN7 drivers, 2x 5U4G rectifiers; pseudo-dual power supply, two-chassis designAnodized aluminium chassis (black or silver), PTFE tube socketsMade in USAfrom $4,499
- EnvySingle-ended Class A, transformer-coupled; directly heated 300B power tubes, CV-181 (6SN7) driver tubes; zero global feedback, fully automatic bias, point-to-point wiringThe 300B filaments are heated with DC from a circuit separate from the audio supply path, and the anode supply is built on MOSFET transistors and low-noise current sources.5 W into 16 ohmsSolid metal chassis with oiled natural wood (oak or American walnut)Made in Poland$8,899
- HA-300 MK3Single-ended triode (SET), pure Class A; 2x Genalex Gold Lion PX300B, 2x JJ 6SN7, 2x JJ GZ34/5AR4; two-box (amplifier plus outboard power supply), point-to-point hand wiring, EI-core output transformersThe third generation uses Duelund coupling capacitors and a JRC MUSES 72320 electronic volume chip with an ALPS 41-step attenuator.Single-ended triode (SET), pure Class A; 2x Genalex Gold Lion PX300B, 2x JJ 6SN7, 2x JJ GZ34/5AR4; two-box (amplifier plus outboard power supply), point-to-point hand wiring, EI-core output transformersFine sandblasted chassis, black or silver; separate power supply chassis$4,399
- Bigger Ben (Rev 3, 2026)Single-ended Class A, zero feedback, tube (6SL7 input; output tubes 6L6GC, EL34, KT66, KT77, KT88, 6550 or KT90), cathode bias; input transformers and custom output transformers with 8/16/32/100/300 ohm headphone taps plus an 8 ohm speaker tapThe same amplifier also drives loudspeakers through an 8 ohm tap, and its large output transformers provide dedicated taps for headphones.6.5 W into 8 ohms, 5 W into 32 ohmsWood chassis, 15.75 in wide by 9.75 in deepMade in USA$6,400
- Manley LabsAbsolute Headphone AmplifierAll-tube, switchable single-ended or push-pull output stage; custom hand-wound Manley IRON output transformers with Low/Mid/High impedance taps; variable negative feedback 0 to 10 dB; 2x 12AX7 and 4x 6AQ5A (EL90)Volume uses a stepped relay ladder attenuator in 0.5 dB steps, with defeatable Baxandall bass and treble shelving controls.1 W into 12 ohmsBlack, copper or silver (Moon Audio variants)$5,499
- Woo AudioWA22 (2nd gen)Fully balanced, Class-A, transformer-coupled tube design with point-to-point wiring, driving 6SN7 and 6080 tubes.Anodized aluminum chassis, PTFE tube sockets, ALPS RK27 potMade in USAfrom $2,699
- Euforia EvoOutput-transformerless (OTL) tube amplifier with point-to-point wiring, weighing 7 kg.UPOCC point-to-point wiring; PsVane CV-181 Mk2 + NOS 6N13S tubesPrice on request
- EliseHand-built tube amplifier rated at 200 mW, recommended for 32 to 600 ohm headphones.PsVane 6SN7 driver tubes, matched NOS 6N13S power tubesPrice on request
Solid-state amplification
Transistor and Class-A designs with the current reserves hard planars ask for.
- FerrumOORFully balanced, proprietary discrete power amp technology; four-wire Ferrum Power Link DC input with sense lines; output transistors biased never to turn offPower link cable carries two power wires and two feedback wires so the supply voltage stays flat at the amplifier input.8 W into 60 ohms, 1.6 W into 300 ohmsMade in Poland$2,275
- HPA4THX-888 (Achromatic Audio Amplifier) feed-forward error-correction amplifier; 100% analog signal path; 256-step relay gain controlUses the same patented THX AAA topology as the Benchmark AHB2 power amplifier and rates bandwidth from 0.01 Hz to above 500 kHz.6 W into 16 ohmsMilled aluminium faceplate and sides, brushed aluminium top, bottom and rear; black or silver faceplateMade in USA$3,499
- GS-X mk2Balanced, dual-mono, Class A, discrete transistor; +/-20 V rails; low/medium/high gain; doubles as a line preampHeadAmp states every unit is designed, assembled and serviced at its shop in Charlottesville, Virginia.8 W into 25 ohms, 6 W into 50 ohmsTwo chassis (amplifier and power supply, each 14.5 x 9 x 2.5 in); colours: polished black, satin black, polished silver, polished blue, satin blue, satin red, satin grey, satin green, satin purpleMade in USA$2,995
- SPLPhonitor xeSolid-state with dual power amp for the balanced output, +/-60 V internal analog supply; Phonitor Matrix crossfeed and angle simulationThe 4-pin XLR output is driven by a separate power amp that gives twice the power of the 6.35 mm jack.1 W into 600 ohms, 2 W into 300 ohmsMade in Germany$3,000
- Pass LabsHPA-1cClass A, low feedback, wide bandwidth; discrete JFET input stage and direct-coupled MOSFET output stage; single-ended 6.35 mm output; also works as a line preampThe 'c' revision adds local regulation to the servo circuit and an upgraded power supply, which Pass Labs says cut noise by about 10 dB.3.5 W into 20 ohms, 200 mW into 300 ohmsBrushed aluminium chassis, black or silver (per Moon Audio)Made in USA$4,045
- Woo AudioWA12 ZirconFully balanced, Class A, zero feedback, solid-state; eight current amplifiers per channel; dual power supply (linear AC or internal lithium-ion battery)Besides three conventional headphone outputs it carries a direct-drive True-Ribbon 4-pin XLR output, and the internal battery runs for 16+ hours.7.5 W into 8 ohms, 6.5 W into 30 ohmsDual-layer chassis machined from billet aluminium, black or silver anodisedMade in USA$7,999
Energizers
High-voltage amplifiers that drive and bias electrostatic headphones.
- SRM-T8000Hybrid: low-noise 6922 dual-triode first stage and high-current emitter-follower output stage; balanced input with no coupling capacitor, transformer or inverting stageMaximum output is 470 Vrms (1,330 Vp-p) at 1 kHz with 0.01% or less distortion, and it has four inputs including an option slot.580 V bias, Hybrid: low-noise 6922 dual-triode first stage and high-current emitter-follower output stage; balanced input with no coupling capacitor, transformer or inverting stageNon-magnetic chassis construction; black (BK) and standard versions listedMade in Japan$6,090
- SRM-700THybrid DC-amplification driver unit: FET input stage with twin 6SN7 vacuum tube output stage; balanced XLR and RCA inputsFrequency response is DC to 100 kHz measured with one SR-009S, and harmonic distortion is 0.01% or less at 100 Vrms output.580 V bias, Hybrid DC-amplification driver unit: FET input stage with twin 6SN7 vacuum tube output stage; balanced XLR and RCA inputsMade in Japan$3,400
- Blue Hawaii Special EditionTwo-chassis electrostatic energizer (amplifier plus separate power supply) with two Stax Pro-bias (580 V) outputs; 2 RCA and 1 XLR inputs, RCA and XLR preamp outputsSpecified output is 1,600 V peak-to-peak with 0.003% THD at 1 kHz, and frequency response 5 Hz to 20 kHz within 0.3 dB.580 V bias, Two-chassis electrostatic energizer (amplifier plus separate power supply) with two Stax Pro-bias (580 V) outputs; 2 RCA and 1 XLR inputs, RCA and XLR preamp outputsColours: satin black, polished silver, satin grey, satin blue, satin champagne, satin sunset; machined aluminium spike feetMade in USA$6,995
- Woo Audio3ES (2nd generation)Push-pull, transformer-coupled tube output stage with four 300B power tubes; driver stage selectable between 6SN7 tubes or precision op-amps (HYBRID); 5U4G rectifierSame two-tier chassis as the WA33; the top section is coupled to the power supply by Woo's internal coupling architecture.580 V bias, Push-pull, transformer-coupled tube output stage with four 300B power tubes; driver stage selectable between 6SN7 tubes or precision op-amps (HYBRID); 5U4G rectifierAnodised aluminium chassis, black or silverMade in USAfrom $9,999