Luxman SQ-38U User Manual

5 (2)



Owner`s Manual


Precautions·············································································································· 1 Names and Functions······························································································ 2 Connections and Connection Diagram····································································· 6 Operations··············································································································· 8 How to Use Remote Control···················································································· 9 SQ-38u Block Diagram·························································································· 10 Specifications········································································································· 11 Before Asking for Repair Services··········································································· 12


Installation place

This product shall be installed in a well-ventilated and effectively heat-released place.

Especially, installation of this product where direct sunlight is present, where the temperature rises excessively high such as close to a heater, or where it is humid or dusty may cause a malfunction even if heat is efficiently released. Therefore, do not install this unit in such places.

Ventilation holes

Do not block the top and bottom faces because this product is a heat-generating amplifier that contains vacuum tubes. If the amplifier is installed on a rack or the like, secure ample space for cooling and leave the door open. Do not pile up other things on the amplifier and never put articles on it. Failure to observe this may cause a malfunction.


For heat dispersal, do not install this equipment in a confined space such as a book case or similar unit.









Precautions in connecting with other components

When connecting this product to input devices such as a CD/ DVD player and a tuner, be sure to turn off the power of this product and all other connected devices. Failure to observe this may generate a strong noise resulting in speaker damage or cause a malfunction.

The pin-plug to be inserted in each input terminal of this product shall be pushed in firmly. If the grounding terminal is inadequately connected, noises including hum may be generated, resulting in an adverse S/N ratio.

Cautions in connecting speakers

When making speaker system connections, exercise extra care not to short-circuit between ! and @ of the speaker terminals and speaker input terminals of this product. If a signal is applied to the amplifier with its circuit left short-circuited, a large current may be passed through the output circuit and cause a malfunction.

The sound is not generated immediately after the power supply is turned on.

This amplifier is equipped with a time muting circuit in order to separate the output circuit. Therefore, no sound is generated immediately after the power supply is turned on.

If the volume control of the amplifier is moved to a high sound level before the time muting circuit is canceled, a large sound is suddenly generated. Please be advised that the volume control shall be set to a low level at first and adjusted after sound comes out of the speakers.



Batteries used for remote controller shall not be exposed to excessive heat such as sunshine, fire or the like.

Repair and adjustment

When repairs or adjustments are needed, please ask the dealer where you bought the unit.


For cleaning, use a piece of soft cloth to wipe the unit such as cleaning cloth available on the market. If the unit has become remarkably dirty, remove the dirt with soft cloth absorbing a small amount of neutral detergent, and then wipe the unit with dry cloth. Do not use a solvent like benzine or thinner because such a substance can damage the exterior.


Luxman SQ-38U User Manual

Names and Functions























1. Operation switch (OPERATION)

3. Separate switch (separate)

Toggles the power on and off. When connection of the input/output terminals is performed, be sure to turn off this switch. When the power is turned off and on again, put 1 minute or more between off and on.

2. Speaker selector (speakers)

Selects either of 2 speaker systems, A or B, located at the rear panel.

off : No sound is generated from any speakers. The headphone output cannot be disabled.

A : Selects the A system speaker terminal. B : Selects the B system speaker terminal.

A+B : Simultaneously activates both A and B system speakers.

When both speaker terminals are simultaneously used, select speakers with impedance of 8 ohms or more because both output terminals are connected in parallel.

Separates the pre-amplifier and main-amplifier each other. off : Uses this unit as a normal pre-main amplifier.

on : Feeds external signals from the MAIN IN terminal on the rear panel to the main-amplifier section.

When the separate switch is set to on, the volume control of this unit cannot adjust the volume of the speakers connected to this unit. Volume adjustment shall be performed at the input device side such as the control amplifier connected to the MAIN IN terminal.

Entry of direct output into the MAIN IN terminal from a CD/ DVD player or other devices that cannot adjust sound volume constantly provides a full power state and accordingly results in the risk of speaker damage.

For such input devices, be sure to use a control amplifier equipped with sound volume adjustment function as a relay, generate sound through the speakers with volume lowered, and adjust the volume to your favorite level.

4. Low cut switch (low cut)

Toggles the low-frequency cutoff function on and off. off : Provides the normal state.

on : Cuts the low-frequency range.


Names and Functions

5. Mode switch (mode)

Changes the output mode.

mono : Mixes the signals from right and left channels. stereo : Provides normal stereophonic reproduction.

6. Monitor switch (monitor)

Reproduces the data from the recorder on the monitor. Selection of ON enables to reproduce the data from the recorder. Selection of OFF enables to reproduce the data from the source selected with the input selector.

7. Input selector (INPUT SELECTOR)

Selects an input device from the devices such as a CD/DVD player and a tuner connected to each input terminal.

This selector has 5 positions consisting of PHONO, CD, LINE-1, LINE-2, and LINE-3 that correspond to each input terminal on the rear panel. To select an input source, set the indicator to the position of the source to be reproduced.

8. Pilot light

Turns orange when the power is turned on.

9. Volume control (VOLUME CONTROL)

Adjusts the sound volume.

Sound is not generated when this control is rotated counterclockwise to the end. The sound volume gradually becomes higher as the control is rotated clockwise.

10. Remote control photoreceiver (R)

Receives signals from the accessory remote control. Do not block the front of the photoreceiver.

11. Sound volume indicator

Indicates the sound volume level.

This indicator blinks during the muting time immediately after turning on the power and at activating the mute function using the main unit or remote control.

12. Balance (balance)

Adjusts the balance of sound volume between right and left channels. Rotating this switch counterclockwise causes the left sound volume to be enhanced, and rotating the switch clockwise causes the right sound volume to be enhanced. This switch shall be set to the center position under normal conditions and rotated to make adjustment if necessary.

13. Mute button (mute)

Temporarily mutes the sound. Pressing this button activates the mute function and blinks the sound volume indicator resulting in no sound generated. Pressing this button again to cancel the mute function allows sound to be generated.

14. Cartridge selector (cartridge)

Adjusting the input impedance of the amplifier may be required depending on the impedance of the cartridge to be used.

The input impedance of the amplifier is selectable with the cartridge selector.

The selectable positions are MM, MC high, and MC low. Select a position in accordance with the input impedance specified in the operating instructions of the cartridge or your taste.



MC high

MC low

















15. Headphone jack (phones)

Is used to listen to sound with use of stereo headphones. Insert the headphone plug into this output jack.

To listen to sound with only use of headphones, set the speaker selector to off.

16. Tone control for treble (TONE CONTROL, treble)

Controls the frequency characteristics in the high-frequency range. When this switch is set to the center position, flat frequency characteristic is obtained. Rotating the switch clockwise causes the high-frequency range to be enhanced, and rotating the switch counterclockwise causes the highfrequency range to be attenuated.

17. Tone control for bass (TONE CONTROL, bass)

Controls the frequency characteristics in the low-frequency range. When this switch is set to the center position, flat frequency characteristic is obtained. Rotating the switch clockwise causes the low-frequency range to be enhanced, and rotating the switch counterclockwise causes the lowfrequency range to be attenuated.


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