Plasma is used in massless as the loudspeaker instead of the solid diaphragm found in all other headphones. Plasma does not use moving mass to create sound and does not have the stored energy of conventional drivers. It is very close in mass to the air driven to make sound - this makes it relatively massless, hence the name.

Plasma is not a popular choice for use as a loudspeaker as it introduces a number of design problems. But just because it is difficult does not mean that we can't. Decades of development has been put into overcoming every single one of these.

In brief, plasma typically requires a high voltage to create, is very hot and creates unwanted gases. It is electrically non-linear and has low efficiency making it a difficult load to drive and control. In open air, plasma lacks the mass to drive lower frequencies and so has only been used as a tweeter in loudspeakers.

massless is designed to overcome all of these problems in the pursuit of excellent sound reproduction.

massless addresses safety issues in a number of passive and active ways.

Only safe low voltage is passed to the headphone. That low voltage supply is converted to high inside the headphone itself. The high voltage amplifier is also inside the headphone. All of that is isolated from you. If there is any electrical fault or cable damage, no high voltage is presented to the user and the high voltage in the headphone is cut. All circuitry is cased in enclosures that are electrically insulating, strong and are hipot proof tested.

To prevent the build up of any unwanted gases from the plasma, the gas is gently and continuously extracted from the cell and replaced with fresh air. The gas is catalysed and filtered to prevent NO2 and ozone release.

Safety lockouts prevent unsafe tampering or misuse. Thermal cut-outs prevent damage from overheating. The medical grade power supply is fully standards compliant for safety and interference. massless is designed to be compliant with international standards.

To prevent any damage to connected audio equipment, input signals are galvanically isolated and surge protected. This passively protects your equipment from any internal fault.

massless should not be used outdoors, in a wet or damp environment or with wet or damp hair or skin. massless is not a portable device. Although excess moisture does not present a safety concern it can cause malfunction and damage to the headphone.

As plasma is an ignition source, do not use in areas with flammable gas, aerosols or after the use of hairspray.

massless has been designed to be a distinctive and attractive piece of hi-fi hardware.

The main theme is a retro art-deco look with a hint of steampunk. The base and headset share the same design language. The body of each is a prismatic elliptical shape produced from 3D printed resin.

The front and rear of each are solid aluminium with a brushed finish .The massless logo is engraved into the front of the base and both sides of the headset. The volume knob is a single piece of 3D printed resin with a double oval design and massless logos.

The headband is a simple single piece of stainless steel with a 100% wool felt head pad.

The base is designed to act as a cradle for the headset to dock when not in use.This is wool felt lined and the base has extended legs to allow for easy cable management.

The power light is sakura in colour, similar to cherry blossom and reflecting colour of the plasmas.

No moving parts
No diaphragm
No Bluetooth
No App
No WiFi
No AI
No magnets
No batteries
No remote
No touchscreen
Not IoT
No subscription
No firmware
No processor
No DAC
No DSP

Designed by Adam Chambers, founder of Audio Chambers, massless is the result of over thirty years of dedicated research into plasma loudspeaker technology.

Each aspect of the design has been explored, tested, and refined — culminating in a headphone that redefines what is possible. massless stands alone as the only available headphone in the world to use plasma to generate sound.

Each unit is manufactured in the UK, using as many locally sourced and in-house engineered components as possible — ensuring quality, precision, and a truly independent approach to innovation.

massless is designed to reproduce electronically recorded sound, typically music, in a home or studio environment.

The full range of human audible frequencies is created using a single plasma and as a result there is no colouration of the sound from a moving solid mass.

Subjectively it could be described as clear, detailed and smooth with good timing. As how a product sounds is down to the individual it is best to listen yourself, use the contact form to arrange a demo.

Type - In ear headphone – IEH
Driver - Glow Discharge Plasma
Frequency Response - 10 to 20kHz approximating a Harman curve
Sensitivity - Driven by dedicated pre-amp, line level inputs
Impedance - Line inputs 20k
Weight - Headset 580g
Power Requirements - 30W
Cable Material - High-purity, silver-plated copper
Max SPL - 110dB
Input Connections - RCA or XLR balanced
Headphone Connectors - Mini-XLR unique configuration

The preamplifier can be connected to any balanced or unbalanced (differential or single ended) analogue audio line level stereo source using RCA or XLR connections. Inputs are treated as fully differential (balanced) regardless of the source type. No ground is provided to cable screens or signals due to the galvanic isolation.

Only the RCA OR XLR inputs can be used at any time, not both at once.

A grounded mains power source is required. An earth connection post is provided for an optional additional safety ground or to use a common ground from the system to other audio equipment.

The headphone requires the power and signals from the dedicated preamplifier base. Other preamplifiers cannot be used with the headphone. Other headphones cannot be used with the preamplifier.

To listen to phonograph records a phono preamplifier will be required.

Any digital source will need to be converted to analogue, massless has no digital signal conversion built in.

The glow discharge plasma is directly driven by a single ended class-A silicon carbide high voltage MOSFET power amplifier integrated into the headphone along with the integrated high voltage power supply.

All internal audio circuitry from preamp to headphone is DC coupled and 100% analogue. The inputs are galvanically isolated.

The base provides separate linearly regulated power supplies for the left and right channels.

The earpiece (including the electrodes), gas filter, headband and earbuds are all user replaceable. massless is designed to be serviceable by electronics engineers with experience in high voltage repair.

The headphone itself will get warm as it contains a hot plasma, high voltage supply and power amplifier. The heat is predominantly directed to the outside of the headphone via ceramic heatsinks.

massless is not compatible with hearing-aid use, but is compatible with glasses as it is in-ear with no surrounding pad.

If you have further questions or any other query please use the contact page, the envelope icon top right.