AIYIMA's latest TPA3255 power amplifier has PFFB function and is equipped with 48v5a GAN power supply. 

Parameter:
Chipset: TPA3255+NE5532
Replaceable operational amplifier chips: RT3609SM, OPA2604, OPA2134, LM4562, JRC5532, OP275GSZ, OPA1612, MUSES01/02/03, etc.
Distortion:0.0015%(@1W)
Signal-to-noise ratio:≥≥116 dB
Frequency response: 20Hz-20KHz (±1DB)
XLR input sensitivity: 3.8Vrms (19dB)
RCA input sensitivity: 1.9Vrms (25 DB)/1.1Vrms (28.5 DB)
Speaker impedance: 4-8Ω
Stereo maximum output power: 2x300 W (@4Ω) 48V10A
Input mode: RCA+XLR
Trigger: 12v Tigger input
Sub Out: 20Hz~150Hz/600Hz(-3dB) (adjustable output cutoff frequency)
Supported equipment: decoders, preamplifiers, computers, CDs, mobile phones, MP3, etc.
Output mode: 2.0 passive speaker+Sub
Working power supply (DC): 36-48V
Packaging size (length*width*height): 146mm*79mm*90mm

Amplifier output frequency response
Bass output frequency responseBass output level scan

Amplifier output distortion scan – 8R/36V/48V