Introduction
Thank you for purchasing the Nobsound TPA3221 Mini Stereo Digital Power Amplifier. This device is designed to provide high-quality audio amplification for your home audio system, featuring both line-level and MM phono inputs. Please read this manual carefully before operating the device to ensure proper setup, optimal performance, and safe use.
Safety Instructions
- Power Supply: Use only the specified power adapter (24V/4.5A) provided with the amplifier. Using an incorrect power supply may damage the unit and void the warranty.
- Ventilation: Ensure adequate ventilation around the amplifier. Do not block ventilation openings or place the unit in an enclosed space.
- Moisture: Keep the amplifier away from water, moisture, and high humidity environments. Do not operate with wet hands.
- Heat: Avoid placing the unit near heat sources such as radiators, heat registers, stoves, or other heat-producing appliances.
- Cleaning: Disconnect the power before cleaning. Use a dry, soft cloth. Do not use liquid cleaners or aerosol sprays.
- Servicing: Do not attempt to service this product yourself. Refer all servicing to qualified service personnel.
Package Contents
- Nobsound TPA3221 Mini Stereo Digital Power Amplifier
- Power Adapter (24V/4.5A)
- User Manual
Product Overview
Front Panel
Image: Front panel of the Nobsound TPA3221 amplifier, showing the input selector switch, power indicator, tone bypass switch, bass knob, treble knob, and volume knob.
- PHONO / RCA / OFF Switch: Selects between Phono input, Line input, or powers off the unit.
- Power Indicator: Illuminates when the unit is powered on.
- Bypass / Tone Switch: Engages or bypasses the Bass and Treble tone controls.
- Bass Knob: Adjusts low-frequency output.
- Treble Knob: Adjusts high-frequency output.
- Volume Knob: Controls the overall output volume.
Rear Panel
Image: Rear panel of the Nobsound TPA3221 amplifier, detailing the PHONO IN (RCA), LINE IN (RCA), Speaker Output (SPK OUT), and DC IN power port.
- PHONO IN (RCA): Input for turntables with MM (Moving Magnet) cartridges.
- LINE IN (RCA): Standard stereo RCA input for other audio sources (CD player, TV, PC, etc.).
- SPK OUT (Speaker Output): Binding posts for connecting passive speakers (Left and Right channels).
- DC IN (18V-28V): Power input port for the external power adapter.
Internal Components
Image: Internal view of the Nobsound TPA3221 amplifier, highlighting the TPA3221 amplifier chip, NE5532 op-amp chips, NJM2608 phono preamp op-amp chips, TD1663 power management chip, and audiophile-grade inductors.
The amplifier utilizes a TPA3221 chip for powerful stereo output, complemented by NE5532 op-amp chips and NJM2608 phono preamp op-amp chips for signal processing. A TD1663 power management chip ensures stable power delivery, and audiophile-grade inductors contribute to sound quality.
Setup
- Connect Speakers: Connect your passive speakers to the 'SPK OUT' binding posts on the rear panel. Ensure correct polarity (+ to + and - to -) for both left (L) and right (R) channels. Tighten the connections securely.
- Connect Audio Source:
- For a turntable with an MM cartridge, connect its RCA output cables to the 'PHONO IN' RCA jacks on the rear panel.
- For other audio sources (e.g., CD player, TV, PC, smartphone), connect their RCA output cables to the 'LINE IN' RCA jacks on the rear panel.
- Connect Power: Insert the DC plug of the provided power adapter into the 'DC IN' port on the rear panel. Then, plug the power adapter into a suitable wall outlet.
- Initial Power On: Set the front panel switch to 'OFF' before connecting power. Once all connections are made, switch the front panel selector to either 'PHONO' or 'RCA' to power on the unit and select your desired input. The power indicator light will illuminate.
Operating Instructions
- Power On/Off and Input Selection: Use the multi-function switch on the front panel to select your audio input ('PHONO' or 'RCA') or to power off the unit ('OFF').
- Volume Adjustment: Rotate the 'VOLUME' knob clockwise to increase the volume and counter-clockwise to decrease it. Start with a low volume setting before playing audio to avoid sudden loud sounds.
- Tone Control:
- Use the 'BASS' knob to adjust the low-frequency response and the 'TREBLE' knob to adjust the high-frequency response.
- The 'BYPASS / TONE ON' switch allows you to engage ('TONE ON') or bypass ('BYPASS') these tone controls. Bypassing the tone controls provides a more direct audio path, which some users prefer for a neutral sound.
- Playing Audio: Once the desired input is selected and volume is set low, start playing audio from your source device. Adjust the volume to your preferred listening level.
Maintenance
- Cleaning: Regularly wipe the unit with a soft, dry cloth to remove dust. Do not use abrasive cleaners or solvents.
- Ventilation: Ensure the ventilation holes are clear of dust and obstructions to prevent overheating.
- Storage: If storing the unit for an extended period, disconnect it from power and store it in a cool, dry place.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound output |
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| Distorted sound |
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| Humming or buzzing noise |
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Specifications
- Model: TPA3221
- Output Power: 100W x 2 (into appropriate impedance)
- Number of Channels: 2 (Stereo)
- Input Voltage: DC 18V-28V
- Inputs: MM Phono (RCA), Line In (RCA)
- Output: Speaker Output (Binding Posts)
- Tone Control: Bass, Treble, Bypass function
- Item Weight: Approximately 2.2 pounds (1 kg)
- Package Dimensions: Approximately 10.04 x 8.66 x 2.48 inches (25.5 x 22 x 6.3 cm)
Warranty and Support
Nobsound products are designed for reliability and performance. For warranty information, please refer to the documentation included with your purchase or contact Nobsound customer support directly. If you encounter any issues not covered in this manual, please reach out to Nobsound customer service for assistance.
Contact Information: Please visit the official Nobsound website or your retailer's support page for the most current contact details.
