While I would have liked a 4 channel chip with about 20 Watt per channel, the local parts store didn't have any yet, so I opted for two TA8215AH stereo chips, selected by their low price in this particular store. The design? Oh well, there isn't much to it. The circuit I used is almost an exact copy of the circuit suggested in the Toshiba data sheet. I only made a very few changes, but including an important one - the one that makes it possible to use this circuit in a computer, without getting power supply and hard disk noise!
Click here to download the full size of the above Circuit.
These chips can deliver 15 Watt RMS per channel, into 4 Ohm loudspeakers. That's more than enough even for loud home use. The peak power current consumption, when saturating all four channels at the same time, would be 12A, which gives good chances that the computer won't reset from power supply shutdown in such a situation! When using 8 Ohm speakers, the output power and the current consumption are cut down to one half. In fact, that's my situation, because my present speakers are 8 Ohm.
The amplifier has a typical distortion in the neighborhood of 0.04%. That's good enough, in my opinion, for a computer sound system, while surely with discrete parts I could have obtained even lower distortion. The gain delivered by the TA8215 is a whopping 50dB, which is MUCH more than needed. So I had to include an attenuator at the input, in order to be able to use the full dynamic range of the sound card.
Here is the complete schematic diagram of one stereo amplifier. Of course, I used two of these for my quad amplifier - and if you want, you can use three to make a 5.1 amplifier! You can click the schematic to get a higher resolution version for printing.
R1 with R2 forms a voltage divider that attenuates the input signal by 24dB. Considering the chip's 50dB gain, that still leaves 26dB overall gain, slightly more than enough to fully saturate the amplifier when the sound card works at maximal output. C1 blocks DC at the...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: