XY-C50L 50W+50W Bluetooth 5.0 Amplifier Board with Case & Mobile App Control

Specifications

• Model: XY-C50L
• Audio Channels: 2.0 Stereo (Left + Right)
• Output Power: 50W x 2 (Max @ 24V/4Ω)
• Bluetooth Version: 5.0 (Up to 15m range)
• Input Voltage: DC 5V - 24V (Recommended 12V-24V for best performance)
• Control Method: 360° Infinite Rotary Encoder (Volume/Play/Pause) + Sinilink App
• Output Impedance: 4Ω - 16Ω
• Protection Features: Reverse Polarity, Short Circuit, Overheat (Self-Recovery)

      Audio Inputs:

• Bluetooth 5.0 Wireless
• AUX (3.5mm Stereo Jack)
• U-Disk (USB Flash Drive, FAT32)
• USB Sound Card (Direct PC connection via USB-A)

Project Evolution

• Prerequisites: If you have previously used simple audio receivers like the MH-M18 or PAM8403 (3W) amps, you know the frustration of low volume and lack of bass.
• The Upgrade: The XY-C50L is a massive leap forward. It moves you from "making noise" to High-Fidelity Audio Engineering. This board allows you to drive serious 4-inch to 8-inch bookshelf speakers, giving you deep bass and crisp highs that 5V modules simply cannot produce.
• Effort Level: Intermediate. Requires basic screwdriver assembly for the case and stripping wires for speaker connections. No soldering required for the main inputs if using a standard DC barrel jack.

Wiring Guide

Pin Mapping:

• DC+ / DC-: Connect your power supply here. Center positive if using a barrel jack adapter.
• SPK1 (Left): Connect to Left Speaker (+/-). Do not bridge the grounds of Left and Right speakers!
• SPK2 (Right): Connect to Right Speaker (+/-).
• USB Port: Insert a FAT32-formatted USB Drive with MP3 files, or connect to the PC for Sound Card mode.

Package Includes:

•  1 x XY-C50L Main Amplifier Board
• 1 x Top Cover Plate
• 1 x Bottom Cover Plate
• 1 x Volume Knob Cap
• 1 x Heat Sink
• 1 x DC Power Adapter Connector
• 4 x Brass Standoffs
• 8 x Mounting Screws

Applications

• DIY Bluetooth Boombox: Convert ammo cans or wooden boxes into portable, high-fidelity party speakers.
• Bookshelf Speaker Restoration: Retrofit old passive speakers with modern Bluetooth and App control without external receivers.
• Desktop Audio System: Create a compact PC sound system using the USB Sound Card mode for interference-free digital audio.
• Portable PA System: Drive high-efficiency horn speakers for announcements or outdoor events using a 12V or 24V battery pack.

Frequently Asked Questions (FAQ)

• What is the recommended power supply voltage?
  For maximum 50W output, use a DC 24V supply. For normal listening, 12V-19V is sufficient.
• Why does the sound cut out at high volume?
  This usually indicates your power supply current is too low. The amp enters protection mode. Upgrade to a supply with higher Amperage (e.g., 4A).
• Can I control this amplifier with an App?
  Yes, it supports the "Sinilink" app for EQ adjustment, mode switching, and volume control.
• How do I switch input modes?
  The board automatically detects inputs. Plugging in AUX overrides Bluetooth. You can also switch modes via the App.
• Does it support USB Flash Drives?
  Yes, plug in a USB drive formatted to FAT32 with MP3 files for direct playback.
• Can I connect this to my PC as a sound card?
  Yes, connect a USB-A to USB-A cable from your PC to the board's USB port. It acts as an external sound card.
• Is the acrylic case included in the package?
  Yes, the kit includes the top and bottom acrylic plates and mounting hardware.
• Will this work with 2-ohm speakers?
  No, 2-ohm speakers may draw too much current and trigger protection. We recommend 4Ω to 8Ω speakers.
• Does it have a microphone input?
  No, this is a playback-only amplifier. It does not have a microphone pre-amp input.
• How do I pair with Bluetooth?
  Power on the board. The blue LED will flash. Search for "XinYi" on your phone and tap to pair.
• Can I use this in a car (12V)?
  Yes, it works perfectly with a standard 12V car battery system.
• Is the volume knob infinite or fixed?
  It uses a rotary encoder (360° infinite spin) for digital volume control, which is more durable than analog pots.
• What is the Bluetooth range?
  In an open area without obstacles, the range is approximately 15 meters.
• Does it save the volume level when powered off?
  Yes, the Sinilink app settings and volume level are typically recalled upon restart.
• Can I bridge the outputs for a 100W mono channel?
  No, the TPA-class chip inside is already configured in BTL mode. Bridging outputs will damage the board.
• Why is there a static noise?
  Check your ground connections. If using a shared power supply with other modules, you may need a ground loop isolator.
• What is the size of the DC barrel jack?
  The board typically uses a terminal block or a standard 5.5mm x 2.1mm DC socket adapter (included in some wiring kits).
• Does it get hot during operation?
  It runs cool for normal use. A small heatsink is included which Probots Lab Verified as sufficient for general 50W usage.
• Can I turn off the Bluetooth connection sound?
  Yes, via the Sinilink App, you can often disable or adjust the system prompt volume.