Samson QH4 Channel Headphone Owner’s Manual

Samson QH4 Channel Headphone

Important Safety Information

1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with dry cloth.
7. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
8. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
9. Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wide blade or the third prong is provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for the replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched particularly at the plugs, convenience receptacles, and at the point where they exit from the apparatus.
11. Only use attachments/accessories specified by the manufacturer.
12. Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when
    moving the cart/apparatus combination to avoid injury from tip-over.
13. Unplug the apparatus during lightning storms or when unused for long periods of time.
14. Refer all servicing to qualified personnel. Service is required when the apparatus has been damaged in any way, such as a power supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus have been exposed to rain or moisture, does not operate normally, or has been dropped.
15. This appliance shall not be exposed to dripping or splashing water and no object filled with liquid such as vases shall be placed on the apparatus.

WARNING

TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COV-ER (OR BACK) AS THERE ARE NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

Introduction

Thank you for purchasing the Samson QH4 4-channel headphone monitoring system. The QH4 provides an elegant solution for headphone monitoring, either on stage or in the studio. The perfect addition to your home recording studio, podcasting setup or just kicking back listening to music, the QH4 delivers super clean, loud, audio fidelity.

The QH4 is a specially designed headphone distribution amplifier that allows you to control the level balance between four individual sets of headphones. Providing over 280mW of power to each headphone channel, the QH4 is compatible with virtually all popular headphone models. And its compact, elegant design, fits into any desktop or mobile application.

In the box, you’ll find a registration card enclosed—please don’t forget to follow the instructions so that you can receive online technical support and so we can send you updated information about this and other Samson products in the future. We recommend you keep the following records for reference, as well as a copy of your sales receipt.

Serial number: _________________________
Date of purchase: _________________________

If you have any questions or comments regarding the QH4 or any other products from Samson, do no hesitate to contact us at support@samsontech.com.

With proper care and maintenance, your QH4 will operate trouble-free for many years. Should your QH4 ever require servicing, a Return Authorization (RA) number must be obtained before shipping your unit to Samson. Without this number, the unit will not be accepted. Please visit www.samsontech.com/ra for an RA number prior to shipping your unit. Please retain the original packing materials and, if possible, return the unit in its original carton. If your QH4 was purchased outside of the United States, contact your local distributor for warranty details and service information.

Features

• Four-channel stereo headphone distribution amplifier
• Maximum output power on each channel regardless of the number of headphones connected
• Four independent 1/4” stereo headphone channels
• Individual volume control on each headphone channel
• Two balanced 1/4” line input connectors
• Stereo 1/8” Aux input and output jacks for daisy chaining multiple QH4 Headphone Amplifiers together
• Master Mute and Mono-summing switches

Quick Start

Follow this basic procedure for setting up and using your QH4 4-Channel Headphone Amplifier.

1. Turn the MASTER Volume knob all the way down until it is in the off-position (rotate counterclockwise until it clicks), and turn all four headphone channel volume knobs to their minimum (fully counterclockwise) setting.
2. Connect the included power supply to the QH4, and plug it into an AC wall socket, but leave its power off for the moment.
3. Connect the outputs from the device you want monitored to the Left and Right INPUTS on the QH4 rear panel. The QH4 accepts both balanced and unbalanced signals. It is recommended to use balanced 1/4” TRS cables because it minimizes extraneous noise from entering the signal path.
4. Connect headphones to the 1/4” headphone output jacks.
5. Play an audio signal into the QH4 inputs.
6. Raise the MASTER volume half way (to the 12 o’clock position).
7. Slowly turn the channel’s level knob clockwise until you hear the desired level.
8. Repeat the previous step for all Channels that have headphones connected, making sure to start with the Headphone Volume knob completely counter-clockwise and then slowly raising it until the desired level is achieved.
9. To expand the QH4 to allow for more than four individual headphone outputs, you can connect multiple QH4 amplifiers together by plugging a 1/8” stereo cable into the Aux Output of the first QH4 amplifier and the Aux Input of another QH4 amplifier. You can repeat this step to add as many headphone amplifiers as necessary. The Aux Output jack is after the MASTER Volume/Power control, Mute and Mono switches, so all adjustments to these controls will affect units further down the chain.

NOTE

Before you connect any headphones to the QH4, be sure to double check that the signal source and QH4 amplifier level controls are turned all the all the way down to their fully counter clockwise positions. The QH4 can generate loud signal levels into the connected headphone. We recommend that you exercise extreme caution and care for your ears. Always start with the level controls all the way off and slowly raise the signal to a comfortable listening level.

Front and Rear Panel Call-Outs

1. Line INPUTS – Balanced 1/4” (TRS) left and right inputs. These line level inputs are the main signal inputs to the headphone amp. Plugging into only the L/MONO jack sends the signal to both the left and right.
2. DC Power Input – Connect the supplied power adapter here.
3. AUX IN – Stereo 1/8” inputs for connecting an auxiliary line level input, like that from a smart phone or computer output.
4. AUX OUT – Stereo 1/8” outputs that are tied to the main 1/4” and AUX inputs for linking to another headphone amp, studio monitors or other device that accepts line level signals.
5. Headphone OUTPUTS (CH1–CH4) – Stereo 1/4” headphone outputs. Note: Do not connect headphones with a minimum impedance less than 16Ω.

Top Panel Call-Outs

1. MASTER Volume/Power – This rotary knob controls the level sent to the individual headphone output channels and powers the QH4 on and off. Turn the control clockwise to turn the system on. Turn the knob counterclockwise until it clicks to turn the system off.
2. MUTE Switch – This switch mutes all of the headphone outputs.
3. MONO Switch – When pressed, the left and right inputs will be summed together into a single mono signal.
4. Headphone Volume (CH1–CH4) – Control knobs used to adjust the level of the headphone outputs.
5. Power Indicator – This white LED will illuminate when power is on indicating the QH4 is ready for operation.

Specifications

• Input Connectors 2 x 1/4” balanced TRS, 1/8” stereo unbalanced TRS
• Max Input Level +21dBu, 1% THD
• Input Impedance 20kΩ
• Frequency Response 20Hz to 20kHz ±0.5dB
• Noise floor -114dBu, 22k BW unweighted
• Dynamic range 122dB, 22k BW
• Signal to noise ratio 96dB, re 1mW at 32Ω load
• Aux Outputs 1/8” stereo unbalanced TRS
• Max Aux Output Level +14dBu, 1% THD
• Aux Output Impedance 100Ω
• Headphone Outputs 4 x 1/4” stereo TRS
• Max Output Power 282mW per channel, 0.5% THD at 32Ω
• Headphone Frequency Response 20Hz to 20kHz -1dB @ 32Ω
• Controls MASTER Volume knob, Master MUTE switch, Master MONO switch, 4 x Channel Volume knobs
• External Adapter 15VDC, 800 mA, pin positive
• Weight 0.88lb / 0.4kg
• Dims (LxWxH) 4.88” x 4.88” x 1.57” / 124mm x 124mm x 40mm

Block Diagram

Troubleshooting

• Issue
  
  • No Power (power indicator is not lit)
• Solution
  • Make sure that the included power supply is connected to the QH4 amplifier.
  • Make sure that the QH4 power supply is plugged into an AC outlet.
  • Turn the MASTER Volume/Power knob clockwise until it clicks into the On position.
• No Audio
  • Make sure the QH4 is turned on.
• Distorted or bad audio
  • Ensure that all audio connections are securely attached.
  • Reduce the output volume of the source audio device.
  • Reduce the volume of the QH4 headphone channels.

If these suggestions do not solve your problem, contact your nearest Samson dealer or Samson distributor.
If you have any questions or comments regarding the QH4 or any other products from Samson, do not hesitate to contact us at support@samsontech.com.