What is it

This is a power adapter that is recommended to be used with the Louder and Maped series of ESP32 and Raspberry Pi-based devices. Originally, this power adapter comes from ASUS laptops, but after testing and comparing different models, I stopped at this one as it produces no hearable noise or hissing, good power figures, and stable work with D-class amps

Features

• Color: Black
• Compatible Boards: see below
• Input: 100-240V /50-60Hz
• Output: 19V 3.42A
• Adapter Power: 65W
• Plug Tip Size: 5.5mm*2.5mm
• Certified: FCC, CE, UKCA

Compatibility list

ESP32 Boards

• Louder-ESP32 and Louder ESP32 Plus
• Louder Esparagus (DUAL model can also be used with USB-PD power adapters)
• Amped ESP32 and Amped ESP32 Plus
• Amped Esparagus (DUAL model can also be used with USB-PD power adapters)

Raspberry boards

• Louder Raspberry Hat and Louder Raspberry Hat Plus
• Louder Raspberry Pi Media Center (DUAL model can also be used with USB-PD power adapters)
• Amped Raspberry Pi Hat
• Amped Raspberry Pi Media Center

Adapter Capability

• Input Power (adapter): 65 W

• Usable Audio Output Power (80% efficiency):

65 W × 0.8 ≈ 52 W total

This 52 W is the total continuous power available for all audio combined.

Key Formulas

• RMS Voltage:
  V_RMS = sqrt(P × R)

• Output Current:
  I = sqrt(P / R)

Where:

• P = power per speaker (W)
• R = speaker impedance (Ω)

Single Speaker (PBTL mode)

If only one speaker is connected, it can use the full ~52 W:

⚠️ Note: At 8 Ω, the required voltage exceeds the 19 V supply, so the actual power will be limited below 52 W.

Two Speakers (Stereo Configuration)

With two speakers, power splits across channels:

• ~26 W per channel

Practical Observations

• The 19 V supply voltage becomes the limiting factor at higher impedances (especially 8 Ω).
• Lower impedance speakers (2–4 Ω) allow higher current draw and better utilization of available power.
• The adapter is well-matched for 2×20–30 W systems, depending on speaker impedance.
• Real-world output will vary depending on:
  • amplifier design (BTL, Class-D behavior)
  • thermal limits
  • Power supply sag under load

Final Notes

• Avoid significantly exceeding the voltage requirements of your speakers. For smaller speakers, use DAC/AMP gain settings to reduce the voltage swing over the speakers.
• This 19 V / 65 W adapter is a strong match for mid-power stereo systems, but not intended for high-power (>50 W per channel) setups.
• Always leave headroom (~10–20%) to prevent clipping and distortion.

Connector specs

Barrel jack used is spaced at 6mm hole/2mm pin, which is typically 5.5/2.5mm jack on the male side.

The screw terminal is connected in parallel to the barrel jack; you can use either interchangeably.

On the latest boards (starting from Amped-ESP32), I switched to barrel jack with thick middle pin with a 2.5mm pin, it’s a bit unusual but still common enough in the laptop world. It is far more comfortable in handling high currents, and importantly, much more sturdy and resistant to desoldering.