Driver unit for Earspeakers
SR-303 Classic

■ The essence of wide band range. 

The movement toward wider band ranges in the world of audio is evident. For example, in the appearance of SACD and DVD audio, it is much like the mega-pixel of CCD light-receiving elements in digital cameras.  What will CCDs, which have already topped the 10 million mark, carry out? It isn’t simply a question of images not deteriorating as a result of enlargement. The real benefits come from the ability to show every single human eyelash with absolute clarity and from the richness of gradation of shading.  Electrostatic earspeaker systems are being reassessed as next-generation audio systems that make it possible to achieve an astonishingly wide range and now, their real value is being recognized.  Vacuum tube output stage transformer made possible by use of the electrostatic method, ideal pure balance operation with no need for an inverted circuit, a DC amplified configuration… The new SRM-006tII has evolved into a new territory with wider band range and detailed refinements. 

■ Features 

The SRM driver unit shows the true value of electrostatic earspeakers.
Pure balance, DC amplifier configuration.
The key concept is the output stage employing a high sound quality vacuum tube 6FQ7 (6CG7), and further refinements have been introduced into all the individual parts.
A wider range than ever before. There’s no end to technical evolution.

Wide range: In order to make maximum use of the wide-range properties of SACD and DVD audio, the circuit have been constantly been revised, resulting in a wider than ever replay frequency range. 

Heater power supply: Adopting a rectifier circuits combining low-noise, low-loss Schottky barrier diodes and large electrolytic capacitors. Low-ripple DC power source improves the SN ratio. 

Output stage: A simple two-stage amplifier configuration using a high-resistance dual three-pole tube 6FQ7 (6CG7) results in straightforward properties that are transparent and clear sound quality. 

Input: It’s possible to switch between three systems (two RCA input systems and one XLR input system). Pure balance circuit: The electrostatic transducer is driven by electrodes set on both sides of the diaphragm which carry the push-pull signals. This is thus virtually the only replay system that enables the listener to enjoy replay unique to balance transmission without the need to pass through a transformer or an inversion amplifier. The input stage makes use of a hand selected low-noise FET. Unit also employs a total of six acoustic high sound quality relays (three on both sides). Simultaneous switching of the hot side and the cold side of the two-system RCA input means that the input source is isolated of direct current.  Almost no interference between different devices. 

Equipped with parallel output terminals: Input 1 can be directly connected to for example an SACD player for pure quality listening with a shorter signal path, while the output connected to a pre-amplifier or power amplifier with volume control simultaneously. 

Use of high sound quality 4-stage volume control: Connection is possible with line level devices such as CD players including XLR. 

Front panel: Brushed Aluminum silver finish and designed with rounded panel corners. 

■ Specifications
●Frequency response DC 80 kHz / +0, -3 dB (in the case of use of one SR-404 unit)
●Rated input level 200 mV / 100 V Outputs
●Maximum input level 30 V r.m.s. / at Minimum volume
●Amplification 54 dB (x 500)
●Total harmonic distortion distortion: max. 0.02% at 1 kHz 100 V r.m.s. (in the case of use of one SR-404 unit)
●Input impedance 50 KΩ / XLR balance 50KΩ×2
●Number of inputs RCA×2, XLR×1 (balanced)
●Maximum output voltage 300 V r.m.s. / 1 KHz
●Standard bias voltage DC 580 V
●Power voltage 120-240V ±10%, 50 to 60 Hz (adjusted for your area)
●Power consumption 49 W
●Temperature range for use Between 0º and 35ºC, max. 90% (no condensation)
●External dimensions 195 (w) x 103 (h) x 375 (d) mm (including VR knob and pin jack (20 + 10)
●Weight 3.4 Kg
●Vacuum tubes 6FQ7/6CG7 type x 2
The standards and external appearance of this unit may be changed without prior notice in order to make improvements.
Black version

Copyright (C) 2007 STAX Ltd. All Rights Reserved.