MAX9708/MAX9709 25W/50W class D - version 3

The third edition of the popular MAX9709 25/50W class D amplifier is ready. Adapted to the cheap production size of various Asian PCB manufacturers 50x50mm ()") in addition to a suitable housing"DP5050", also Seedstudio, it offers following features:"

  • adjustable gain (22dB, 25dB, 29.5dB, 36dB)
  • Overtemperature (110 ° C, 158 ° C)
  • Mono/Stereo operation (2x25W, 1x50W)
  • differential inputs via pin headers
  • "single-ended" input via 3.5mm jack and potentiometer (Alpha)
  • Speaker connections via Phoenix connectors (screw-on in AC coupling)
  • expandable with active 2.1 crossover network and/or digital interface (USB, SPDIF)

AGML battery charger


IMG_5290 (2)

IMG_5317 (2)

IMG_5291 (2)

A new batch/lot is by Elecrow made, here some details have been changed.
-larger SMD Elkos possible (from 8 × 10-> 10 × 10)

  • axial leaded capacitors possible (wider range of lowest ESR)
  • Most of the vias opened (unpainted)
  • 2 possible configurations of potentiometer (Alpha/Alps) 5.08 & 2.54 mm
  • Changed placement of charge-pump capacitors
  • optinale for stereo/Mono LED indication
  • Open back pad for possible interfacing a heat conduction pad/heatsink
  • "plated slots" for power Jack
  • Positive guidance to VDD via capacitor (copper surface slotted behind power socket)

The Board is 1:1 with the MAX9708 compatible (automotive - AECQ100).

MAX9709 v3.1

There are test results here: MAX9708/MAX9709 measurements

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6 responses

  1. Sachin A Nigudkar says:

    I want to buy the PCB. how can I proceed?


  2. herry says:

    please go to ebay, so i can buy it with my credit card

    i don’t know how to pay…in this web

  3. herry says:

    i want to buy this, how..?

  4. Heinz says:

    Where can I get the MAX9708/MAX9709 25W/50W class D - version 3 or buy? and by the way. From the PCB manufacturers, I the only good one. There are also black sheep. This is not in any case.


  1. 11 December 2013

    […] is issa: MAX9709 25W/50W class D - version 3 - #360customs _ α β γ δ ε ζ η κ λ μ ξ [...]

  2. 9 February 2015

    […] Comparative measurements between the TPA3132D2 (2 different boards) and the MAX9709. […]

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