STAX SRM-1

Commentary

This driver unit was developed to directly drive the SR series condenser ear speakers of Stacks.

The circuit has a DC configuration using FET at the first stage and high-voltage transistors at the second to third stages.

The power supply section uses a newly developed CA-X super-shunt power supply with an output impedance of 1m Ω or less based on the same design concept.
The SRM-1 achieves 0.24 μ V power supply noise by using cutless core transformer.

Parts are made of glass epoxy boards, metal film resistors, low-noise Zener diodes for the reference voltage of the constant voltage power supply, and other materials that take sound quality and distortion into consideration.

The volume uses 2-axis 2-series type, and the distortion can be reduced by only passing the signal through one stage of VR.
In this volume, the left and right channels are linked, but unbalanced channels can be adjusted independently.

The chassis is made of all-aluminum, eliminating magnetic materials such as iron that adversely affect sound quality.

It can also be used vertically by replacing the rubber feet.

Model Rating

Type	Driver unit
Frequency characteristic	5 Hz ~ 20 kHz + 0 -4dB or less (30 V, when one SR ∑ is used)
Amplification factor	60dB
Harmonic distortion factor	0.05% (1 kHz, 100 V, when using 1 SR ∑)
Input impedance	50k Ω
Input level	100mV
Maximum output voltage	410V(1kHz)
Bias voltage	230V
Semiconductor used	FET : 8 Transistor : 14 SiD : 6 pieces Zener diode : 2 pcs
Operating temperature range	0 ~ 40 ° C or Less
Power supply voltage	100 VAC ± 10%, 50Hz/60Hz
Power consumption	20W
External dimensions	Width 150x Height 87x Depth 370 mm Width 75x Height 162x Depth 370 mm (when placed vertically)
Weight	2.0kg