HO200 - Headphones S.M.S.L - Free user manual and instructions

Product Type	High Resolution Headphone Amplifier
Model	HO200
Brand	S.M.S.L
Dimensions (W x H x D)	210 x 40 x 170 mm
Weight	1.23 kg
Power Supply	AC 100-240V, 15V/24W adapter
Power Consumption	< 30 W (operating), < 0.1 W (standby)
Inputs	1 x Balanced (XLR), 1 x Unbalanced (RCA)
Headphone Outputs	1 x 4.4mm Balanced, 1 x XLR 4-pin Balanced, 1 x 6.35mm Unbalanced
Pre-Outputs	1 x Balanced (XLR), 1 x Unbalanced (RCA)
Output Power	6W x 2 (16 Ω), 3W x 2 (32 Ω)
Signal-to-Noise Ratio (SNR)	140 dB
Output Noise	1.0 µV
Total Harmonic Distortion + Noise (THD+N)	0.00006% (1 kHz, 32 Ω)
Frequency Response	20 Hz - 500 kHz (-3 dB)
Gain Settings (Unbalanced)	Low (-10 dB), Middle (0 dB), High (17 dB)
Gain Settings (Balanced)	Low (-4 dB), Middle (6 dB), High (23 dB)
Input Impedance	10 kΩ
Output Impedance (Headphone)	Near 0 Ω
Protections	DC, overvoltage, overload protection
Construction	Fully balanced design with 4 ultra-low distortion PLFC circuits
Volume Control	Specially designed potentiometer for reduced channel deviation
Controls	Power switch, gain selection, output selection, input selection, volume knob; classic retro toggle switches
Indicators	Blue LED (power on), flashing red (protection active)
Warranty	1 year free repair (normal use), 7-day return/replacement
Included Accessories	Power adapter (AC 100-240V)

Frequently Asked Questions - HO200 S.M.S.L

How do I connect the HO200 to my audio source?

Use the XLR balanced input or RCA unbalanced input on the rear panel. Connect your source (e.g., DAC, player) accordingly. Select the corresponding input using the front panel input selector.

Which headphone outputs are available and how do I choose?

The HO200 has three headphone outputs: 4.4mm balanced, XLR 4-pin balanced, and 6.35mm unbalanced. Use the output selector to choose the appropriate output. For balanced headphones, use 4.4mm or XLR; for single-ended, use 6.35mm.

How do I set the gain correctly for my headphones?

The HO200 offers three gain levels. For sensitive IEMs, use Low gain (unbalanced -10dB, balanced -4dB). For most over-ear headphones, Middle gain (0dB/6dB) is suitable. For hard-to-drive headphones, select High gain (17dB/23dB). Start with low gain and increase gradually to avoid distortion.

What do the indicator lights mean?

When powered on, the indicator light turns blue. If the light flashes red, it indicates that the system's protection circuitry has been triggered (e.g., due to DC offset, overvoltage, or overload). In this case, turn off the amplifier, check connections, and reduce volume before powering on again.

Can I use the HO200 as a preamp?

Yes, the HO200 has pre-outputs (balanced XLR and unbalanced RCA). You can connect these to a power amplifier or active speakers. Note that the pre-output impedance is 44 Ω (balanced) and 22 Ω (unbalanced).

What is the maximum output power and into which impedances?

The HO200 delivers 6W x 2 into 16 Ω and 3W x 2 into 32 Ω. It is capable of driving a wide range of headphones, including low-impedance and high-impedance models.

How do I clean and maintain the HO200?

Disconnect the power before cleaning. Use a soft, dry cloth to wipe the exterior. Avoid using liquids, solvents, or abrasive cleaners. Ensure ventilation openings are free from dust. No internal user-serviceable parts; refer to qualified service personnel for repairs.

What safety precautions should I take?

Use only the specified voltage (AC 100-240V). Install in a well-ventilated, cool, dry place away from direct sunlight, heat, and moisture. Do not open the cabinet. Always turn down volume before connecting or disconnecting headphones to prevent hearing damage.

What is covered under warranty?

The warranty covers free repair within one year of purchase for normal use. Within 7 days, you can return or replace a defective product (if it does not affect second sales). Keep your purchase receipt or online transaction screenshot as proof. Damage from misuse, unauthorized modification, or improper parts voids the warranty.

Why does my amplifier go into protection mode (red flashing light)?

Protection mode activates if the amplifier detects DC offset, overvoltage, or overload. This can happen due to faulty cables, shorted headphone connections, or excessive volume levels. Check all connections, reduce gain/volume, and power cycle. If the issue persists, contact S.M.S.L support.

USER MANUAL HO200 S.M.S.L

The contents of this manual may be changed with the edition, and are subject to change without notice

Ver 1.0

Safety Notes

• Install this unit in a well ventilated, cool, dry, clean place-away from direct sunlight, heat sources, vibration, dust, moisture, or cold..

- Use the voltage specified on this unit Only. Using this unit with a higher voltage than specified is dangerous and may cause fire, damage to this unit, or personal injury. Our company will not be held responsible for any damage resulting from the use of this unit with a voltage other than that specified.

- Do not attempt to modify or fix this unit by yourself. Contact alesperson or customer service when any service is needed. The cabinet should never be opened for any reason.

- When not planning to use this unit for long periods of time (i.e. when going on vacation), disconnect the power cable from the AC wall outlet.

Important note:

The product specifications and information mentioned in this manual are for reference only. The content of this manual is subject to change without notice.

Warranty Terms

1. The Term of Service

Foshan Shuangmusanlin Technology Co., Ltd promises to offer good-quality products. If the product is broken in 7 days after purchasing when you use it normally, you can choose to send it back for return, replacement or repairing (only the product does not affect the second sales can be returned). Repairing for free in one year if you use it normally.

1. Date of purchase is in accordance with the date on invoice or receipt uesd by seller, and if you buy it on line, you can show the screenshot of trade.

2. If an inappropriate usage causes the unit damaged, the warranty will be void. As below.

3. All damages by inappropriate use, including using it under non-normal working environment or without following the instructions.
   • Dismantling, refitting, repairing by user in private.

4. Causing damage by using some fittings instead of the designative or accredited ones.

5. Cannot provide credible proof of purchase.

6. Sending it back to our company for repairing.

7. Contact your S.M.S.L Audio reseller for a return or replacement.

Features

• Fully balanced design, 4 ultra-low distortion precision linear feedback circuit (PLFC)!
- The distortion is as low as 0.00006%, and the A-WTD is as low as 0.00005% (-126dB)!
- Ultra-low noise power supply design, so that the output noise is as low as 1.0uV, SNR up to 140dB !
• High output power, 16 ohm output power up to 6W, 32 ohms up to 3W;
- The specially designed volume potentiometer greatly reduces channel deviation;
• 3 gears gain control, low gain is specially optimized for IEM;
• Pre-out function, can be used as Hi-End pre-amp;
• Classic retro toggle switch operation;
• Ultra-compact design, very suitable for desktop headphone system;
• High-precision low-temperature drift resistance, performance is not affected by temperature;
• High-quality relay and non-impact sound design;
• 20Hz to 500kHz frequency response;
• The headphone amplifier has comprehensive protections such as DC, overvoltage, and overload protection;
• Built-in high-efficiency and low-noise power system.

Specifications

Inputs......Balanced x1, Unbalanced x1

Headphone outputs:

4.4mm Balanced x1, XLR 4 Pin x1, 6.35mm unbalanced x1

Pre-outputs......Balanced x1, Unbalanced x1

Output Power:

6W x 2 (16 Ω)

3W × 2 (32 Ω)

SNR....140dB

Output Noise....1.0uV

THD+N....-123dB, 0.00006% (1kHz, 32 Ω)

THD+N....-120dB, 0.00013% (20-20kHz, 32 Ω, 0dB)

THD....<-125dB

Input Impedance.... 10kΩ

AMP output Impedance....Near 0 Ω

Pre-output Impedance:

Balanced 44Ω

Unbalanced 22Ω

Frequency Response.... 20Hz - 500kHz(-3dB)

Gain:

Unbalanced.... Low(-10dB), Middle(0dB), High(17dB)

Balanced.... Low(-4dB), Middle(6dB), High(23dB)

Power consumption(EN60065)....<30 W

Power consumption in standby mode.... <0.1W

Size.....210X40X170mm(WxHxD)

Weight....1.23kg

Specifications are subject to change without notice.

Display Interface and Instructions

1 Power switch

2 Indicator light

3 Gain selection

4 Output selection

5 Input selection

6 Volume

7 4.4mm balanced headphone jack

8 6.35mm headphone jack

9 Balanced headphone jack

10 XLR balanced input

11 RCA input

12 RCA Pre-output

13 XLR Pre-output

14 Power AC input(AC100-240V)

Note:

- Please turn down the volume before connecting the headphones to avoid excessive volume damage to the headset.

- According to the advice of health experts, do not listen to the headphones for a long time so as not affect your hearing.

- The indicator light turns blue after it is turned on. Flashing red means the system has triggered protection.