1. Introducció
The Nobsound NS-03D EL34 Valve Tube Amplifier is a high-fidelity stereo audio single-ended integrated amplifier, chosen by many music lovers for its exceptional sound quality. Integrated amplifiers combine the engineering and performance of separate ampelevadors i preamplifiers into a single, space-saving unit, reducing the overall footprint of your audio system.
Featuring a classic tube combination of 6H8C and EL34B, the NS-03D delivers firm and full mids, smooth highs, and deep lows. It is particularly well-suited for genres such as vocals (offering a natural and sweet rendition), strings, pipes, and jazz. This amplifier is designed to provide a pure and clean musical experience, perfect for enjoying during leisure time.
2. Contingut del paquet
Please check the package carefully to ensure all items are present and undamaged. The tubes are packed individually to protect them during transit.
- 1 × Nobsound NS-03D Tube Ampmés viu
- 2 × EL34B Tubes (PSVANE brand)
- 2 × 6H8C Tubes
- 1 × 5U4C Tube
- 1 × cable d'alimentació

3. Producte acabatview
The Nobsound NS-03D features a pure handmade design with a stainless steel chassis combined with a solid wood panel, giving it a classic aesthetic.




4. Configuració
4.1 Instal·lació del tub
- Carefully unpack all tubes from their protective packaging.
- Identify the correct sockets for each tube type. Refer to Figure 3.3 for tube identification (6H8C, EL34B, 5U4C). The amplifier chassis may also have labels near the sockets.
- Align the pins of each tube with the corresponding holes in the socket. Ensure the keyway (if present) on the tube base aligns with the notch on the socket.
- Gently push each tube straight down into its socket until it is firmly seated. Do not force the tubes, as this can bend or break the pins.
4.2 Connexions d'àudio
- Font d'entrada: Connect your audio source (e.g., CD player, DAC, preamplifier) to the RCA input terminals labeled 'IN' on the rear of the amplifier (see Figure 3.2). Use high-quality RCA cables for optimal sound.
- Ponents: Connect your speakers to the 'SPEAKER' output terminals. Ensure you match the impedance of your speakers (4Ω or 8Ω) to the corresponding terminals on the amplifier. Connect the positive (+) terminal of your speaker to the positive terminal of the amplifier, and the negative (-) terminal of your speaker to the negative terminal of the ampmés viu.
4.3 Connexió d'alimentació
- Assegureu-vos el amplifier's power switch is in the 'OFF' position.
- Connect the provided power cord to the AC power input on the rear of the ampmés viu.
- Plug the other end of the power cord into a suitable wall outlet (220V-240V/50-60Hz).
5. Instruccions de funcionament
- Encès: Flip the 'POWER' toggle switch to the 'ON' position. The tubes will begin to warm up, and the VU meters may illuminate. Allow a few moments for the tubes to reach their optimal operating temperature.
- Control de volum: Slowly turn the 'VOLUME' knob clockwise to increase the sound level. Adjust to your desired listening level.
- Apagar: Per apagar el amplifier, flip the 'POWER' toggle switch to the 'OFF' position.
El amplifier features a self-biasing design, simplifying operation as no manual bias adjustments are required for the tubes.
6. Manteniment
- Neteja: Mantenir el amplifier clean and free from dust. Use a soft, dry cloth for cleaning. Avoid using liquid cleaners or abrasive materials.
- Ventilació: Assegureu-vos una ventilació adequada al voltant amplifier. Do not block the vents or place the amplifier in an enclosed space, as proper airflow is crucial for tube longevity and performance.
- Substitució del tub: Vacuum tubes have a finite lifespan. If you notice a degradation in sound quality or if a tube fails, it may need replacement. Consult a qualified technician for tube replacement if you are unsure.
- Substitució de fusibles: El amplifier has an integrated fuse. If the unit does not power on, check the fuse located in the AC power input on the rear panel (see Figure 3.2). Replace with a fuse of the same type and rating (e.g., FUSE 5A).
7. Solució De Problemes
- Sense so:
- Check all cable connections (input source, speakers, power).
- Assegureu-vos el amplifier is powered on and tubes are glowing.
- Verify the input source is playing and its volume is adequate.
- Comproveu el fusible.
- So distorsionat:
- Assegureu-vos que la impedància de l'altaveu coincideixi amb la ampterminals de sortida del lificador.
- Check for damaged cables or faulty tubes.
- Reduce the input signal level if it's too high.
- No Bass/Treble/Balance Controls:
- Això amplifier is designed for a pure, uncolored audio signal and does not include separate bass, treble, or balance controls. Adjustments should be made at the source component (e.g., DAC, media player) if desired.
8. Especificacions
| Característica | Especificació |
|---|---|
| Potència de sortida | 8W × 2 (ultra linear connection default) |
| Tubs | 1 × 5U4C, 2 × 6H8C, 2 × PSVANE EL34B |
| Resposta de freqüència | 20Hz - 25KHz |
| Impedància de sortida | 4Ω, 8Ω |
| Distorsió | ≤ 1% (1 kHz) |
| Impedància d'entrada | 100 KΩ |
| Sensibilitat d'entrada | 500mV - 2000mV |
| Relació senyal/soroll (SNR) | 90 dB |
| Font d'alimentació d'entrada | 220V-240V / 50-60Hz |
| Potència del transformador | 150W |
| Dimensions (W×D×H) | 360 × 220 × 55 mm |
| Pes | 12 Kg |
| Certificació | CE |
9. Consells d'usuari
- The EL34 tubes are known for outstanding highs and mids, while the 6N9P (likely a typo for 6H8C in the original description) contributes to deep lows, offering a well-balanced tonal profile.
- This Class A Single Ended Amplifier design is chosen to minimize distortion, providing a clean and accurate audio reproduction.
- El amplifier's pure handmade construction with a stainless steel chassis and solid wood panel makes it a classic and aesthetically pleasing addition to any audio setup.
- For optimal sound, ensure your audio source is of good quality, as the amplifier will faithfully reproduce the input signal without additional tone shaping.
10. Garantia i Suport
Nobsound provides a 1 any de garantia per al amplifier unit and a 2 mesos de garantia for the vacuum tubes. Our goal is to ensure 100% customer satisfaction. For any support inquiries or warranty claims, please contact your retailer or Nobsound customer service.





