CalcProgrammer1
New Member
Well, my friend gave me an old PC speaker set. It was a 2.1 set, but the digital controller chip that controlled EQ and volume was useless. So, I took out the motherboard and looked to see what parts were available. I desoldered some chips.
There were 3 main ones:
TDA7370B (Quad amplifier for car stereo)
TL074CN (Quad op-amp)
KIA324P (Quad op-amp)
I decided (after reading the datasheets) that I'd try building a working amplifier out of these parts. I went for the TDA7370B and wired it up on a circuit board. I basically built the "Double Bridging" circuit that the datasheet described, but using a plain old standard board from RadioShack. This does work, but it isn't great for subwoofer purposes. All frequencies come through (I knew this would happen as there's no EQ or crossover) but when I play a low note (using my PDA and a tone generator), the volume is pretty quiet.
I'm wondering if and how I could use the remaining chips to make a preamplifier to boost the low signal from my PDA (or PC or other device) to make the subwoofer louder. Also, when no song or tone is playing, the amplifier will make random clicks, static, and buzzing sounds, but once I start playing music, it stops. Why would it do this, and what can I add to stop it?
There were 3 main ones:
TDA7370B (Quad amplifier for car stereo)
TL074CN (Quad op-amp)
KIA324P (Quad op-amp)
I decided (after reading the datasheets) that I'd try building a working amplifier out of these parts. I went for the TDA7370B and wired it up on a circuit board. I basically built the "Double Bridging" circuit that the datasheet described, but using a plain old standard board from RadioShack. This does work, but it isn't great for subwoofer purposes. All frequencies come through (I knew this would happen as there's no EQ or crossover) but when I play a low note (using my PDA and a tone generator), the volume is pretty quiet.
I'm wondering if and how I could use the remaining chips to make a preamplifier to boost the low signal from my PDA (or PC or other device) to make the subwoofer louder. Also, when no song or tone is playing, the amplifier will make random clicks, static, and buzzing sounds, but once I start playing music, it stops. Why would it do this, and what can I add to stop it?