Overview
The Nobsound VOL-3 is a passive preamplifier designed for high-fidelity audio systems. It provides precise volume control without amplifying the audio signal, aiming to preserve the original sound quality from your source components. This device requires no external power.
Primary Function: To act as a volume attenuator between an audio source (like a DAC or CD player) and a power amplifier or active speakers.
Features & Specifications
Core Features
- Passive Design: Contains no active amplification circuitry. It does not add gain or require any power source (batteries or AC).
- High-Quality Volume Control: Utilizes an ALPS RK27 (A50K) dual potentiometer for smooth, step-less stereo volume adjustment.
- Lossless Audio Path: Designed to minimize coloration and distortion, aiming for a transparent signal pass-through.
- Premium Connectors: Features US CMC-816U RCA connectors made of oxygen-free copper and plated with 24K gold for optimal signal transfer and durability.
- Compact & Durable Build: Housed in a CNC-machined full aluminum alloy chassis for durability, shielding, and a modern aesthetic.
Technical Specifications
| Specification | Detail |
|---|
| Model | VOL-3 (JMQ399H-FS) |
| Type | Passive Preamplifier / Volume Controller |
| Amplifier Type | Passive (No Gain) |
| Power Source | None Required (Fully Passive) |
| Input Connectors | 1 x Stereo RCA Pair (Left & Right) |
| Output Connectors | 1 x Stereo RCA Pair (Left & Right) |
| Output Channel Quantity | 2 (Stereo) |
| Audio Output Mode | Stereo |
| Potentiometer | ALPS RK27 A50K Dual Channel |
| Enclosure Material | Aluminum Alloy |
| Dimensions (W x D x H) | 94 x 52 x 43 mm (3.70" x 2.05" x 1.69") |
| Net Weight | 224 g (0.49 lb) |
| Package Contents | 1 x Passive Preamp & Volume Control Unit |
Use Guide
1. Package Contents
- Nobsound VOL-3 Passive Preamp Unit
Note: Audio cables and other system components are not included.
2. Front & Rear Panel Overview
Front Panel:
- Volume Knob: The large, knurled knob controls the output volume. Rotate clockwise to increase volume, counter-clockwise to decrease. The control is smooth and continuous (no steps or clicks).
Rear Panel (from left to right when facing the back):
- INPUT (RCA Jacks): One pair of RCA jacks (typically white for Left, red for Right). Connect these to the audio output of your source device (e.g., DAC, CD player, PC sound card).
- OUTPUT (RCA Jacks): One pair of RCA jacks (white for Left, red for Right). Connect these to the input of your amplifier or active speakers.
3. System Connection & Setup
- Power Down: Ensure all components in your audio system (source, amplifier, speakers) are turned off.
- Connect Source: Using RCA audio cables, connect the output of your audio source (e.g., the "Line Out" or "DAC Out") to the INPUT jacks on the VOL-3.
- Connect to Amplifier/Speakers: Using another set of RCA cables, connect the OUTPUT jacks on the VOL-3 to the input of your power amplifier or active (powered) speakers.
- Set Initial Volume: Before powering on, rotate the VOL-3's volume knob fully counter-clockwise to the minimum (quietest) position.
- Power On Sequence: Turn on your audio source first, then your amplifier or active speakers.
- Adjust Volume: Slowly rotate the VOL-3's volume knob clockwise to your desired listening level. Use the volume control on the VOL-3 as your primary master volume. You may need to set the volume on your source device to a fixed, high level (e.g., 80-100%) for optimal performance.
4. Compatible Devices
This preamp is designed to work with components that have a standard "line-level" output. Ideal use cases include:
- Source Devices: Digital-to-Analog Converters (DACs), CD/DVD/Blu-ray players, computers with sound cards, streaming audio devices, phono preamps (with line-level output).
- Destination Devices: Power amplifiers (both integrated and separate), active/powered speakers, powered subwoofers (via line-level input).
Important Compatibility Note: Because this is a passive preamp with no gain, it is best suited for systems where the source device provides a robust output signal (typically 2V RMS or higher) and the amplifier or active speakers have sufficient gain themselves. It may not provide adequate volume control with very low-output sources.
⚠️ Important Notes & Troubleshooting
- No Power or Amplification: This unit does not plug into a wall outlet and does not boost signal strength. It only attenuates (reduces) the signal.
- Cable Quality: Use well-shielded, good-quality RCA cables. Poor quality cables can introduce noise or hum, which may be more noticeable in a passive setup.
- Insufficient Volume: If maximum volume is too low, ensure your source device's output level is set to maximum. The limitation may be due to low source output or insufficient gain in your amplifier.
- No Sound: Double-check all cable connections are secure and correct (Output to Amp, Input to Source). Verify all other components in the chain are powered on and set to the correct input.
- Channel Imbalance at Low Volume: Some potentiometers can exhibit slight channel imbalance at very low volume settings. This is normal. Adjust the volume to a higher setting for balanced output.
Warranty and Support
This product is covered by an 18-Month Limited Warranty provided by the manufacturer, Nobsound.
For warranty service or technical support, contact the seller through your Amazon purchase history or visit the Nobsound store page on Amazon for more information.
Manufacturer: Nobsound
Model Number: JMQ399H-FS
ASIN: B07GRLV7XG
