R○This product contains high-voltage circuitry. To avoid dangerous electric shock, do not disassemble or modify the unit.

RISK OF ELECTRIC SHOCK

DO NOT OPEN!

The SRM-T8000 contains high voltage circuitry.
It is dangerous to disassemble or to remodel it. Please observe Don'ts.

Page

１．Safety information (Please read first)

2

２．Features / Precautions for use

3

３．Switches and functions － Front panel

4４．Terminals and functions － Rear panel

5５．Connection example － Standard connection

6６．Connection example － When using preamplifier or attenuator

7７．Block diagram

8８．Troubleshooting

9９．Specifications / Care and Cleaning / Accessories

10Thank you very much for purchasing the SRM-T8000 driver unit for STAX earspeakers. Please read this manual carefully in order to use the unit safely and to bringout its maximum performance for many years of listening pleasure. Please be sure to keep this manual along with the warranty card after reading.

● Prior to use - About WARNING/CAUTION marks
Various WARNING and CAUTION marks are used in this manual for safe

WARNING:usage of the unit. The possible danger or trouble caused by disregarding

Disregarding this mark and mishandling the unit

● In case smoke comes out or unusual smell or sound is perceived,
stop using and shut off the power immediately, and then pull out
mains plug from wall socket.
Further using the unit involves the risk of a fire or electric shock,etc. It is dangerous for a customer to repair the unit. Pleasecontact your audio shop or the service division of our company.

Disregarding and mishandling this mark might
result in injury or physical damage.

● Do not remove the bottom plate or the top cover.
● Do not attempt disassembly or modification.

the marks and mishandling the unit are classified as follows. Please readthe manual with these WARNING/CAUTION marks in mind.

WARNING could result in serious injury or death.
CAUTION

This mark urges user to take precaution (warning included).
Left example shows “electric shock” caution.
This mark tells prohibited actions.
Left example shows “disassembly-forbidden”.
This mark tells actions you must take without fail.
Left example shows “pull out plug from wall socket”.

WARNING:● Do not pull out or insert mains or earspeaker plug with wet handto avoid electric shock.
● Do not use any other mains voltage than indicated.
● Do not bend, twist or pull the power cable by force, nor modify it.
● Do not cover the heat dissipation holes on the top panel andside panels.
● Do not put metal, liquid or other object into the unit.
● Do not touch the output terminal for earspeaker.

CAUTION:
Do not put this product on the following places. Otherwise, it may
cause injury or unit failure.
●Places sensitive to vibration or shock, slanted or exposed todirect sunlight.
●Places with much moisture, humidity and dust.
●Places where temperature differs intensely or near heating appliance (stove, heater, etc.).
●Do not put earspeaker or any other object on the unit. It may
cover the venting holes and cause heat generation resulting inunit failure.

●Dropping or giving a shock should be avoided. It becomes thecause of failure.
●Don't raise volume too much. Listening with large volume could
lead to hearing damage. Listening with moderate volume is recommended both for your ear and for the unit.

2

● The SRM-T8000 is an exclusive driver unit (power amplifier) with 4-input
selector developed in order to ideally drive STAX electrostatic earspeakers.

● The unit incorporates a high-quality double-axis 4-gang volume controller
along with XLR connectors that can connect to all kinds of analog line-level
output terminals.

● The hybrid amplifier configuration with strictly selected low-noise 6922 dual

● There are high-voltage dangerous sections inside the unit. Do not remove
the top cover or the bottom plate, and avoid using the unit in humid or
dusty places.

● Since the driver unit generates heat, do not cover the venting holes on thetop, side and bottom plates. Put it in an airy place if possible, and when
installing it in a rack etc., keep 5cm or more opening above the upper andside surface of the unit. Do not use the unit with side panel down.

triode tube for the first stage and high-current emitter-follower at output
stage brings out the maximum performance of earspeakers. Its natural uncolored sound has been realized by eliminating the coupling capacitor thataffects sound quality.

● The balanced amplifier configuration with low-noise dual triode tube eliminated transformer or inverting amplifier after the XLR balanced input terminal.

● Non-magnetic chassis construction is employed, and only the carefully selected electronic components free from aged deterioration are used taking
both their sonic quality and performance into consideration.

● Since the degree of adhesion of foot is very high, be careful when moving
the unit.

● Take care when "LEVEL CONTROL" is in "EXTERNAL" position, because
in this position the volume of this unit is bypassed and the volume is notcontrolled.

● Since large volume may come out, do not switch "LEVEL CONTROL" to"EXTERNAL" when wearing your earspeaker.

● When the option card is not equipped, do not remove the cover of the optional slot. Using the unit without the slot cover may cause failure of the● The SRM-T8000 is equipped with “direct mode” function, enabling it to connect to preamplifier output terminal or to use your favorite attenuator. Also,
two RCA inputs and XLR balanced input can bypass the incorporated volume controller ( Line 4 input does not have this function).

● Optional extension slot (LINE4) is provided for future use. Refer to the instruction manual of this optional card.

● The foot rubber of the SRM-T8000 features fire-resistant ultra-hard highgrip type and vibration-proof properties. So the unit hardly slides whenplaced on a table etc. Please lift it up when you move it.
3unit.

● Noise such as hum may come out when SOURCE is switched to LINE4
with no option card equipped. This is normal and not a failure.

①Power indicator LED: this blinks for about 1 minuteTop cover

Please do not block up the vent of top-cover and both side.
Please do not put a thing on a ventilation hole.

Air ventafter powered on and lights up when the tube heater iswarmed up. (Even when the unit is turned on right af-

LEVEL (INTERNAL)
5

ter it was turned off, the power indicator blinks again

64for about 1 minute.)

LSOURCE

R

LINE2

7

3

POWER

EARSPEAKERS
PRO-TYPE ONLY

When power on and off:
It is recommendable to turn down the volume control

INTERNAL

1knob to “0” or to set the “LEVEL CONTROL” to “MUTE”.

(BYPASS)

90SRM-T8000

LINE4EXTERNAL

MUTE

82LINE3LINE1LEVEL CONTROL

10VACUUM TUBE INPUT DRIVER UNIT FOR EARSPEAKERS②Power switch: pushing in the switch turns the unit on, andpushing it out turns the unit off.

③Sockets for PRO Type earspeaker: insert 5-pin type①②④③⑥⑤earspeaker plug.

④Volume knob: double-axis structure enables to turn left

Factory default“MUTE” position

Direct input

LEVEL CONTROLLEVEL CONTROLLEVEL CONTROL

and right channel simultaneously. In case right-and-leftchannel volume is unbalanced, adjust the volume by independently turning the separate volume knobs. The front
side is L-CH and the back side is R-CH.

INTERNAL
GREEN
LEDLights

MUTE

EXTERNAL(BYPASS)

INTERNAL

MUTE

GREEN
LED
Blinks

EXTERNAL(BYPASS)

INTERNAL

MUTE

EXTERNAL(BYPASS)RED LED
Blinks※ We recommend to return volume knob to "0 " when you
turn on or off the unit.

⑤LEVEL CONTROL: volume control operation can be switched either tothe internal volume of the unit, or to the external volume using attenuatoror preamplifier.
1. INTERNAL: Green LED lights up and level can be controlled by internal volume.
2. MUTE: Green/Red LED blinks and mutes sound in order to urge you
to pay attention before using external volume.
3. EXTERNAL: Red LED lights up and level can be controlled by pream-⑥SOURCE: input selector.
1. LINE1/LINE2: selects RCA plug input. Use RCA pin cable provided or
your favorite one.
2. LINE3: selects XLR balance cable input. Polarity is 1-SHIELD 2-HOT 3-COLD. When connecting equipment with 3-HOT, use polarity
conversion adaptor or conversion cable.
3. LINE4: can be selected only when option card is used.

plifier or external volume.
4①XLR polarity indication:
XLR balance input polarity is 1-SHIELD, 2-HOT, 3-COLD.
LINE4When connecting equipment with 3-HOT, use polarity con-LINE2LINE1

PARALLEL OUT

SRM-T8000

version adaptor or conversion cable.

RISK OF ELECTRIC SHOCK
DO NOT OPEN

CAUTION!

VACUUM TUBE INPUT
DRIVER UNIT FOR EARSPEAKERS

L

L

50/60Hz 95W
PUSH

HOT

②LINE3: XLR input terminals for equipment provided withXLR balance output.

PUSH

SHIELD② ①③R

LINE3XLR INPUTRRGNDLCOLDSTAX LTD. MADE IN JAPAN③LINE4: optional slot with cover.

SERIAL No.

When option card is not equipped, do not remove thecover. Refer to the instruction manual of this option card.

①②③ ④⑤⑥⑦⑧⑨⑩④LINE2: RCA input terminal.
⑤LINE1: RCA input terminal.
Both LINE1 and LINE2 connect to audio equipment with RCA output (CDplayer, etc.) or to REC OUT terminal of amplifiers.

⑦GND: ground terminal.
In case of hum noise connect this terminal to the ground terminal or tometal part (screw, etc.) of other equipment. Use any available cord for⑥PARALLEL OUT: RCA output terminal. PARALLEL OUT terminal directly

this purpose.

outputs signals connected to LINE1. It can be used for connection to another driver unit or to the amplifier to drive loudspeaker. Remove the ca-⑧AC inlet: insert supplied power cable.

ble when equipment connected to PARALLEL OUT is not used.

⑨Foot: Since the degree of adhesion of the foot is very high, be careful※On rare occasions, signals from source equipment's are distorted when

when moving the unit. Lift it up when you move the unit.

the equipment connected to the "PARALLEL OUT" terminal is poweredoff. In this case, turn on the connected equipment or remove the cablefrom "PARALLEL OUT" terminal.
When adding another SRM-series driver unit using "PARALLEL OUT"
terminal, the power ON/OFF of the added driver unit does not affectsound if its volume is set to zero.
5⑩Voltage indication：depending on your country’s voltage.

－ Standard connection
Before connecting, make sure that "Power switch" is off.

Factory default● Other connection than shown below: when connecting to source equipment with mini stereo jack.

LEVEL CONTROLThe jack is connectable using a commercially available stereo mini plug / RCA plug conversion cable or a conversion plug.
INTERNAL

MUTE

EXTERNAL(BYPASS)First set the volume of source equipment to the usual headphone listening level, and then adjust the volume of the driver unit.

GREEN
LEDLights

LINE4
LINE2

LINE1

PARALLEL OUT

SRM-T8000

RISK OF ELECTRIC SHOCK
DO NOT OPEN

CAUTION!

VACUUM TUBE INPUT
DRIVER UNIT FOR EARSPEAKERS

L

L
50/60Hz 95W

PUSH

HOTSHIELD② ①③

LINE3: XLR connection
Use XLR cable

RPUSH

LINE3
XLR INPUTRRGNDLCOLDSTAX LTD. MADE IN JAPANSERIAL No.

●Usage example of PARALLEL OUT:
① When adding another SRM-series driver unit

LINE outputs of personal computer, digital audio, etc.

② When also using loudspeaker:

When connecting source equipment directly to LINE1 or LINE2 input:

Connect PARALLEL OUT to AUX input terminal of an amplifier.

Connect REC OUT terminal of your amplifier to LINE1 or LINE2.

Adjust the volume controller of amplifier.

When adding another SRM-series
driver unit

LINE output equipments such as DVD, SACD/CD/BS/TAPE/VIDEO, etc.

When using a loudspeaker in combination:
Connect to the pre / pre-main amplifier from the parallel out terminal.
LOUD SPEAKER

Connect REC OUT terminal of your amplifier to LINE1 or LINE2.

PRE-MAIN AMP.
MAIN AMP with Volume control-6-6

When using preamplifier or attenuator
Before connecting, make sure that "Power switch" is off.

Direct input
LINE outputs of personal computer, digital audio, etc.
LEVEL CONTROLINTERNAL

MUTE

1. When using volume controller of amplifier or attenuator, connect toEXTERNAL(BYPASS)

either one of RCA (LINE1, LINE2) or XLR

RED LEDLights(LINE3). Use XLR cable to connect to LINE3.

LINE output equipments such as DVD, SACD/CD/BS/TAPE/VIDEO, etc.

2. In this mode do not connect any source equipment with no volumecontrol, otherwise sound at full volume comes out when you switch
over carelessly.
3. Select SOURCE according to connected input.
Page 4 “Switches and functions Front panel ⑥”

AUX in etc.

OUT PUT

Set “LEVEL CONTROL” knob to “EXTERNAL”.

Pre- or Integrated amplifier or attenuator
Connect the driver unit to PRE OUT terminal of amplifier or attenuator.

LINE4LINE2

LINE1PARALLEL OUT

SRM-T8000

RISK OF ELECTRIC SHOCK
DO NOT OPEN

CAUTION

VACUUM TUBE INPUT
DRIVER UNIT FOR EARSPEAKERSLL
50/60Hz 95W

PUSH

HOTPUSHSHIELD② ①③R

LINE3XLR INPUT

RL

R
GND

COLD

STAX LTD. MADE IN JAPAN7

SERIAL No.

!

“LEVEL CONTROL” is in the position for using integrated volume.
PARALLEL OUTLEVEL CONTROLLINE 1：RCA

High-current emitter follower output stage

EXT.

LINE 2：RCA

Double triode
INT.

L-CH
LINE 3：XLR

Input selector

6922

INT.

LINE 4OPTION SLOTEXT.

LEVEL CONTROLINTERNAL●MUTE EXTERNAL

Output terminals(BYPASS)

Double-axis 4-gang
volume controller●●●● ●GREENLEDLights

●

●

● ●

Toroidal transformer

POWER SUPPLY for MAIN PCB, CONTROL-PCB and OPTION SLOT

BIAS

R-CH

8

No SoundHum noise is heard● Is the plug of Power cable inserted into the wall socket ?

● Are input terminals connected correctly ? If the ground side of cable is● Is the power switch on ?
● Does LED on the front panel light up ?
● See that “LEVEL CONTROL” is not in “MUTE” position.

floated or in poor contact, hum noise may come out.
● In case of buzzing hum noise connect GND terminal to the ground ter-minal or to metal part of other equipment.

● Check that nothing is wrong with connecting cable..

● Connecting GND terminal to window aluminum sash is also effective.

● When connected to pre- or integrated amplifier, check that the amplifier● Is there any poor contact ?

selector is set to connected source..

Sound is distorted● Is supply voltage in stipulated range ?

Turning up the volume too much distorts the sound. Listen with moderate volume.
● See that “LEVEL CONTROL” is not in “EXTERNAL” position. Excessive

input level can distort the sound.

● Is supply voltage in stipulated range ?
● Because of the non-magnetic aluminum chassis hum noise can be in-duced through connected equipment's. If equipment's with large-sizedtransformer or microwave oven etc. are located near driver unit, keepthem away from the unit.
If you have other problems than described above, please contact yourdealer or our distributor in your country.

● When the preamplifier (integrated amplifier) connected to the“PARALLEL OUT” is powered off, it is possible that the sound is distorted because of the lowered impedance. In this case, simply disconnect
the cable. The SRM-T8000 does not affect other connected equipment
even when powered off.

Unbalanced sound between right and left channel● Are input signals all right ?
● Level difference between channels can be corrected by adjusting double-axis volume knobs independently.
● When raising volume slowly from zero, it sometimes happens thatsound does not start to come out at the same time from left and rightchannels. This is normal and not a failure.
● Volume cannot be adjusted ? See that “LEVEL CONTROL” is not in“EXTERNAL” position. Set it to “INTERNAL” position.

9

When you replace the vacuum tube of drive unit, be sure to ask the purchased store or distributor. Disqualified vacuum tube may sometimes
cause breakdown.

● Frequency response: 1Hz - 115kHz +0, -3dB
● Rated input level: 100mV (at 100V output)●Pull out power cable from wall socket and wipe it with dry soft cloth.
When very dirty, wipe off dirt with wet cloth and then again with dry cloth.

● Maximum input level: 30Vrms. (at minimum volume)● Gain: 60dB (x 1000)●Do not use benzine, thinner or alcohol since paint, printing, etc. may● Harmonic distortion: 0.01% or less (1kHz)

come off. Before using chemical dust cloth, check its attached explana-● Input impedance: 50kΩ (RCA input), 50kΩx 2 (XLR input)

tion if it is usable for audio equipment.

● Maximum output voltage: 470Vrms (1330Vp-p) / 1kHz
● Bias voltage: 580V DC● Mains voltage: AC120V/AC220/AC230/AC240, 50/60Hz(depending on your country’s voltage)● Power consumption: 95W/Max. 58W (without optional slot)● Operating temperature: 0 to 35 degrees C (less than 90% humidity,non condensing)● Dimension: 320 (W) x103 (H) x395 (D) mm (maximum protruding portion included)● Weight: 7.3kg

Power cable ････････････････････････････1
RCA cable ･･････････････････････････････1
Owner’s manual ･････････････････････････1● Others: equipped with PARALLEL OUT, optional slot and volume bypass function and mute function.
※Specifications and appearance are subject to change without notice forimprovement.
※This product is adjusted to mains voltage depending on each country.

10

R○3798-1 Shimonanbata, Fujimi-shi, Saitama-ken, Japan 〒354-0004

STAX LIMITED

Tel: +81-49-293-1891 Fax: +81-49-293-1892 URL:www.stax.co.jp
Printed in Japan 2017-05 MP C STAX