I got one of those plastic computer drive bay amps. It had two corny speakers like 2" apart and a headphone jack. It fits into an optical bay. I took it apart out of curiosity. They exhibited a hum when I used the headphone jack. I discarded the swiveling box, speakers and kept the circuit board and cords. The chip inside is a tea2025b STEREO AUDIO AMPLIFIER. Weird thing, the silkscreen on the board said for 12v input.
The power cord with the molex connector was wired to deliver only 5v.
So I look up the specs on the chip and it said it needs a minimum of 3v and a max of 12v. So whoever made this amp was cutting it really close. No wonder it sounded bad.
When I tried it again without the speakers wired in, there was no hum out of the headphone jack and the quality was excellent. I would recommend making a nice headphone amp with a nice aluminum project box, a circuit with the above mentioned chip, and for a happy medium; run it on 9v with 6 AA batteries.
The power cord with the molex connector was wired to deliver only 5v.
So I look up the specs on the chip and it said it needs a minimum of 3v and a max of 12v. So whoever made this amp was cutting it really close. No wonder it sounded bad.
When I tried it again without the speakers wired in, there was no hum out of the headphone jack and the quality was excellent. I would recommend making a nice headphone amp with a nice aluminum project box, a circuit with the above mentioned chip, and for a happy medium; run it on 9v with 6 AA batteries.
Motorboating?
What capacitor values did you use, and where? A schematic or photo would probably be helpful.
All electrolytics are 100uf 16v and input 1uf MKT
Took the pcb from here but made it bigger so i could install small heatsink...
Btw it is motorboating, i think its not burnt or so just maybe caps are "blown"?
image hosting sites
Took the pcb from here but made it bigger so i could install small heatsink...
Btw it is motorboating, i think its not burnt or so just maybe caps are "blown"?
image hosting sites
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