KeVlaR's Audioworld - Stax Electrostatic Headphones

There are headphones and there are headphones, then there are STAX Headphones. STAX themselves go so far as to name them earspeakers as they don't sound like a normal pair of headphones. They have been around for a number of years now and really have a reputation for being the best of the best. Unfortunately here in the UK, there are not many dealers who sell them. Click here for a bigger picture of the STAX earspeakers.

The Lambda-Nova series earspeaker is the fruit of 35-years of experience of STAX that first developed and manufactured the electrostatic headphone, that is the first "earspeaker" in the world.

Different from ordinary headphones, this earspeaker is equipped with neither magnet nor coil, but utilises electrostatic force to generate sophisticated sound. In detail, the core of an earspeaker is composed of a thin diaphragm (oscillatory film) to which a DC voltage of 580V is applied. When an audio signal is applied to the electrodes, an electrostatic force is generated that drives the diaphragm to reproduce the sound. Thanks to this operation prinicple, the earspeaker reproduces sound very naturally and delicately in all nuances.

The sound is very open and airy. The soundstage even seems to project outside of the head unlike other headphones. The sound is also very detailed but musical at the same time, which is difficult to do! On close miked acoustic recordings you may even find that you can hear the artist breathing. When I first heard them they sounded a bit lacking in the bass, but as time went on I found that the bass is actually there but it is heard more than it is felt like with other headphones.

Because they are of an electrostatic design they do need a separate energiser to drive them and one is supplied with each set. Various energisers are available from STAX and top model is a tube driven design that sounds absolutely awesome. Incidentally I use Van Den Hul D102II interconnects to feed these. I also use a specially made extension cable for the actual headphones so that I can listen while in bed!

Internal diagram of STAX Lambda Nova Headphones

All this sound quality does come at a price thought like most things. Although they cost a considerable amount of money they will last a lifetime and you will have to go far to get a better pair than these. Of course STAX do manufacture a better pair in the STAX SR-OMEGA and SRM-T1S Valve energiser but it'll cost you!

Do yourself a favour. Don't take my word for it about theses phones, track a pair down and have listen for yourself. You'll think your speakers are faulty!

One thing I did invest in for the STAX so that they wouldn't get damaged is a model head. I must confess that I did get some funny looks when I went into a women's hair salon / boutique and asked to buy a wig stand! I'm glad I didn't have to buy the wig that went with it. The things we do in the name of hi-fi eh?

Type	Push-Pull Electrostatic Oval Shaped Units Open Back Enclosure
Frequency Response	7 - 41,000 Hz !
Electrostatic Capacity	120 pF including cable
Impedance	133 k Ohms
Sensitivity	100 dB /100 V r.m.s. Input / 1kHz
Maximum Output Sound Level (SPL)	118 dB / 400 Hz
Standard Bias Voltage	580V / DC
Left / Right Indication	L & R indicators are provided on the HEAD BAND and the left channel cable is marked with a dotted line
Ear Pads	High quality synthetic leather
Cable	6-core parallel low capacitance wire / 2.5m (98 inches) in length
Cable Conductor	Oxygen Free Copper
Weight	440 g 295g for body only (without cable)

Frequency Response	DC - 20,000 Hz Deviation within -3 dB (40Vr.m.s. with SR-L Pro Classic
Gain	60 dB
Harmonic Distortion	0.05 % (1 kHz, 100V, with SR-L Pro Classic
Input Impedance	50 k Ohms
Input Level	100mV for 100V out
Maximum output voltage	280V r.m.s.
Power Consumption	DC 12V 4W
Operating Temperature range	0' C to 40' C
Weight	500g