![]() ![]() When the control plug is disconnected, 5v is supplied through the jack and the PNP transistor is kept ON, providing enough voltage across R2 to keep the amp ON. There are two supply voltages in the circuit - one is a 12 volt supply which is available on the audio input board, and the other is a 5 volt supply which is tapped from a regulator on the main amplifier board.Ī 1/8" control plug is used to signal the amp to be muted or not. The mute input of the TDA1554Q is at pin 14. I built the following PNP transistor circuit so that a 5v signal from the raspberry pi will turn ON the amp, and a 0V signal will turn OFF the amp: A little probing around the two boards uncovered both a 5v and 12v source. There are two boards inside the subwoofer of this system - one board is an audio input board, and the other is the main amplifier board. ![]() So do this hack only on a TDA1554Q system!Ī quick look at the TDA1554Q spec showed that Von is >= 8.5v and that Vmute is 3.3 to 6.4v. The TDA1554Q replaced the OM8384J chips that were in older versions - I can't find a spec on the older chip so I do not know if it has the same mute pin. This hack will work on a PC Works speaker system that uses the TDA1554Q amplifier chip. I have two of these systems - one is connected to my tv and the other is used on a raspberry pi running Volumio and shairport. It's certainly not an audiophile setup but like I said, it was 35 bucks. The PC Works speaker system was originally 35 bucks around 15 years ago, and it still sounds great in my opionion. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |