Help - TA2024 Board Trimmer Adjust

[jechus26]

hello, I accidentally turned the knobs of the 2 trimmers of this board, this is 2 trimmers at 50 k ohm each one, I thinking that they were input gain adjustments, but its about dc bias ajust, can someone help me to factory adjust them again) thanks everybody

mini-ta2024-computer-pc-digital-stereo-amplifier-board-dc-12v3a-power-audio-amp-diy-rs1214 — imgbb.com

http://www.wolfteck.com/assets/Tripath TA2024.pdf

 

[FauxFrench]

Hi, Turn the trimmers to about mid position. Put a couple of cheap spakers at the output of the TA2024 amplifier. Start the amplifier up with the source at the input but without any signal from the source. Put your voltmeter (2V DC range) across the two amplifier terminals that are connected to one of the speakers. Try turning one trim-potentiometer to see if the voltage at the voltmeter changes when you turn. If yes, turn the trim-potentiometer until you have a minimum of voltage at the voltmeter. If no, adjust the other trim-potentiometer for a minimum of voltage at the voltmeter. Put the voltmeter across the amplifier terminals conneted to the other speaker and adjust the voltage to a minimum. Remove the voltmeter and turn the source on/up with music. Let the amplifier play for some 30min at normal sound level (it heats up to operational temperature). Put your voltmeter in the 200mV DC range, stop the music from the source and repeat the voltage adjustments as described above. Ready to use on the good speakers!

You do this adjustment twice because the DC off-set voltage varies heavily with temperature. After second round of adjustments, the DC off-set on both channels should be less than 50mV (+ or "-" does not matter) and typically around 20mV.

 

[jechus26]

Hi, Thank you very much Fauxfrench, after the second ajustment, the dc off set is between (01.8 - 02.0) on 200mV DC range. I appreciate your response and I am very grateful, cheers.