Nobsound NS-08E - User Manual

1. This is tube headphone amplifier that can greatly improve the sound quality for
headphones, but also can be used as tube preamp, its 3.5mm headphone jack
also can connect amplifier or active speakers.
2. Default 6J3 vacuum tubes, also can be directly replaced by the following models
6J1, 6ж1П, 6AK5, 6BC5, 403A/B, 5654, EF95, CV850, 6J2, 6ж2П, 6AS6, CV2522,
CV4011, 6J3, 6ж3П, EF94, CV848、6BC6, 6AG5, 6J4, 6ж4, 6136, 6BX6, 6AC7,
6AU6, 6J5, 6ж5П, CV2521, 6F36, 6AH6, 6AN5, 6K4, EF93, 6K5, 6K4П, 6BA6,
6DA6, 5749.
Warm Tips
NS-08E Mini Tube Headphone Amplifier
User Manual
How to Use
Nobsound
1. Connect audio source such as phone, MP3, TV, tablet, computer, CD player etc.
to 3.5mm AUX input of NS-08E, and connect headphone or power amplifier or
active speaker to its 3.5mm output. Recommend high-quality 3.5mm cable.
2. Connect power adapter to NS-08E and then connect power adapter to the socket.
3. Press the red button on the back panel to power it on and warm up for a while.
4. Play music on your audio device, and rotate the volume control to adjust the
volume until perfect and enjoy HiFi music.
Parameters
Audio input: 3.5mm AUX
Audio output: 3.5mm headphone jack
Max output power: ≥1100 mW (32 ohm)
Matched Headphone impedance: 18-600 ohm
Frequency Response: 20Hz - 30KHz
THD: <0.005%
SNR: ≥110 dB
Power supply: DC 6V /2A

Summary

Nobsound NS-08 E Amplifier: Essential Information

Device Functionality and Tube Compatibility

Discusses the amplifier's function as a preamp and lists compatible vacuum tubes for replacement.

How to Use the NS-08 E Amplifier

Details connecting audio sources, power, and operating the device for playback.

Douk Audio U10 Amplifier: Important Details

U10 Warm Tips and Usage Guidelines

Advises on power adapter, input/output connections, tube compatibility, and driving headphones.

U10 Introduction and Features

Highlights stereo inputs, dual outputs, power, tube design, and sound shaping capabilities.

U10 Operation Instructions

Step-by-step guide for connecting power, headphones, audio source, and operating the device.

Douk Audio U10 Amplifier Specifications and Panel Layout

U10 Amplifier Technical Parameters

Lists key specifications including brand, model, inputs, outputs, power, impedance, and dimensions.

U10 Front and Back Panel Overview

Identifies ports and controls on the front and back panels of the U10 amplifier.

Overview

1. Key Features and Specifications
2. Usage Features
3. Maintenance Features
4. Key Features and Specifications (Douk Audio U10)
5. Usage Features (Douk Audio U10)
6. Maintenance Features (Douk Audio U10)

The Nobsound NS-08E Mini Tube Headphone Amplifier is a versatile audio device designed to enhance the sound quality for headphones and can also function as a tube preamplifier. It features a 3.5mm headphone jack that can connect to an amplifier or active speakers, offering flexibility in its application.

Key Features and Specifications:

• Function: This device primarily serves as a tube headphone amplifier to improve headphone audio quality. Its 3.5mm output can also be used to connect to a power amplifier or active speakers, allowing it to function as a tube preamplifier.
• Audio Input: 3.5mm AUX
• Audio Output: 3.5mm headphone jack
• Max Output Power: ≥1100 mW (at 32 ohm impedance)
• Matched Headphone Impedance: 18-600 ohm
• Frequency Response: 20Hz - 30KHz
• THD (Total Harmonic Distortion): <0.005%
• SNR (Signal-to-Noise Ratio): ≥110 dB
• Power Supply: DC 6V/2A

Usage Features:

1. Connectivity:
   • Connect an audio source (e.g., phone, MP3 player, TV, tablet, computer, CD player) to the NS-08E's 3.5mm AUX input.
   • Connect headphones, a power amplifier, or active speakers to the 3.5mm output. High-quality 3.5mm cables are recommended for optimal performance.
2. Powering On:
   • Connect the power adapter to the NS-08E and then plug it into a power socket.
   • Press the red button on the back panel to power on the device. Allow some time for the tubes to warm up.
3. Audio Playback:
   • Start playing music on your connected audio device.
   • Rotate the volume control knob to adjust the volume to your desired level for an enjoyable HiFi listening experience.

Maintenance Features:

• Tube Rolling: The NS-08E comes with default 6J3 vacuum tubes, which are user-replaceable. It supports a wide range of compatible tube models, allowing for "tube rolling" to customize the sound signature. Compatible tubes include: 6J1, 6ж1П, 6AK5, 6BC5, 403A/B, 5654, EF95, CV850, 6J2, 6ж2П, 6AS6, CV2522, CV4011, 6J3, 6жЗП, EF94, CV848, 6BC6, 6AG5, 6J4, 6ж4, 6136, 6BX6, 6AC7, 6AU6, 6J5, 6ж5П, CV2521, 6F36, 6AH6, 6AN5, 6K4, EF93, 6K5, 6Κ4Π, 6ΒΑ6, 6DA6, 5749. This feature allows users to experiment with different tube characteristics to fine-tune the audio to their preference.

The Douk Audio U10 Mini Tube Headphone Amplifier is another variant, offering similar tube amplification benefits with expanded connectivity and power features.

Key Features and Specifications (Douk Audio U10):

• Function: The U10 is a mini headphone amplifier designed to drive a wide range of headphones, including high-impedance models. It also features a built-in voltage boost circuit for consistent high-voltage operation and pluggable sockets for tube and op-amp rolling.
• Audio Input: 3.5mm AUX / Stereo RCA (inputs work simultaneously, but avoid connecting both 3.5mm and RCA inputs at the same time to prevent signal mixing).
• Audio Output: 3.5mm / 6.35mm headphone jack (outputs work simultaneously).
• Max Output Power: ≥1100mW (at 32Ω impedance)
• Matched Headphone Impedance: 18-600Ω
• Frequency Response: 20Hz-30KHz
• Signal to Noise Ratio: ≥110DB
• Input Voltage: DC 5V (≥2A) (Power adapter not included; a high-quality 5V/≥2A adapter is recommended for normal operation).
• Working Voltage Inside: DC 24V (achieved via an innovative built-in voltage boost circuit, even with a 5V input).
• Dimensions (WDH): 95mm69mm30mm / 3.74in2.72in1.18in
• Net Weight: 200g / 0.44lb

Usage Features (Douk Audio U10):

1. Power Connection:
   • Connect the power adapter to the U10 using the provided USB to DC cable.
   • Insert the power adapter into a wall socket. (Note: A power adapter is not included and a 5V/≥2A adapter is required).
2. Headphone Connection:
   • Connect your 3.5mm or 6.35mm headphones to the corresponding output jack on the U10.
3. Audio Source Connection:
   • Connect your audio source to the U10's inputs using a high-quality 3.5mm AUX cable or RCA cable.
4. Power On:
   • Rotate the main knob clockwise to turn on the U10.
5. Audio Playback and Volume Control:
   • Play music from your audio source.
   • Use the volume knob to adjust the output volume.
6. Power Off:
   • After use, rotate the knob anti-clockwise to its leftmost position until the U10 turns off.
   • Disconnect the power adapter.

Maintenance Features (Douk Audio U10):

• Tube Rolling and Op-Amp Upgrading: The U10 features pluggable tube sockets for its 2PCS 6A2 tubes and op-amps. This allows users to easily replace the default 6A2 tubes with compatible models for sound customization (e.g., 6J1, 6ж1П, 6AK5, 6BC5, 403A/B, 5654, EF40, EF95, CV850, 6J2, 62П, 6AS6, CV2522, EF11/732, CV4011, 6J3, 6ж3П, EF96, CV848, 6BC6, 6AG5, 6J4, 6ж4, 6136, 6BX6, 6AC7, EF94, 6AU6, 6K4, 6K5, 6K4П, 6BA6, 6DA6, EF89/93, 5749). The pluggable op-amp sockets also enable op-amp upgrading, providing further avenues for sound shaping and personalization. This design makes the U10 highly adaptable for audiophiles who enjoy experimenting with different audio characteristics.

Nobsound NS-08E Specifications

General

Brand	Nobsound
Model	NS-08E
Category	Amplifier
Language	English