As the frequency of the signal rises, the impedance lowers. At a frequency of 20kHz, the impedance has dropped to roughly 19kOhms. The TDA7293 TDA7294 is a very capable amplifier, and makes a very good account of itself. It’s been used in a number of commercial products and many, many DIY projects. It has a bewildering number of options, even allowing you to use different power supplies for the input and output stage or using another TDA7293 as a second power stage. Another possibility of using TDA7293 is in a Class-G design, with external transistors. It’s a complex arrangement that I have not built. This amp can also be bridged, using the Project 87 balanced transmitter board. You can expect about 150W into 8 ohms from a ±35V supply. It cannot be bridged into 4 ohms, as the effective impedance on each amplifier is too low.

So I think that with good implementation (I didn't even use the "best" schematic or matched preamp) such as using big transformer, high quality capacitors, and using suitably high end (big) speakers, the 7293 will be "comparable" to the mini-crescendo. During the years I have built and tried a great number of different designs utilizing TDA7293 or TDA7294. Some of them had very decent sound (and low THD) some not, but they all had one thing in common which I call “TDA7293 / TDA7294 sound”. It does not mean that it is necessarily a bad thing, some people love that sound. For me it has always been inseparable from listening fatigue. The TDA7293 IC uses a MOSFET power stage, where the others featured use bipolar transistors. The main benefit of the MOSFET stage is that it doesn’t need such radical protection circuitry as a bipolar stage, so unpleasant protection circuit artefacts are eliminated. There are no apparent downsides to the TDA7293, although it was found that one batch required a much higher voltage on the Standby and Mute pins than specified, or the amps would not work. This is not a limitation, since both are tied to the positive supply rail and are therefore disabled. The diagram above shows the pinouts for the TDA7293V (the “V” means vertical mounting). Soldering the ICs must be left until last. Mount the ICs on your heatsink temporarily, and slide the PCB over the pins. Make sure that all pins go through their holes, and that there is no strain on the ICs that may try to left the edge off the heatsink. When ICs and PCB are straight and aligned, carefully solder at least 4 pins on each IC to hold them in place. The remaining pins can then be soldered. Remember, if you mess up the alignment at this point in construction, it can be extremely difficult to fix, so take your time to ensure there are no mistakes. The TDA7293's specifications suggest that it can work with supply voltagesof up to ±50V. It might work with no input signal(and hence no output), but if 4 ohm loads are expected, I wouldn't recommend anything higher than ±35V, while ±42V will suffice if you can supply adequate heatsinking. Naturally, the 42V supplies (obtained from a 30+30V transformer) are preferable if you can afford to lose a few ICs to experimentation.But the same thing happened again, instantly after powering on, a flame shoots out the bottom of the IC and that's it... Transformer T1 should be a toroidal transformer type for minimum electromagnetic trayfield which reduses audio hum and noise. In my case I started with an existing 2x 15V AC 0.75A transformer which is sufficient for around 2x 10Watt RMS. Choose a 20V..35V AC / 30..50VAC transformer when more power is needed. Don't forget the conversion from AC to DC: 15VAC x sqw(2) = 15VAC x 1.41 = 21VDC. The input voltage (positive and negative) may not exceed 50VDC. Difference in THD is rarely audible. If you can hear a difference between 7293 and 3886, I would say it is the difference between mosfet and bipolar in common/most amp designs (they can be designed to sound more similar I believe), where mosfet amp tend to sound "muddy"? The diagram above shows the pinouts for the TDA7293V (the "V" means vertical mounting). Soldering the ICs must be left until last. Mount the ICs on your heatsink temporarily, and slide the PCB over the pins. Make sure that all pins go through their holes, and that there is no strain on the ICs that may try to left the edge off the heatsink. When ICs and PCB are straight and aligned, carefully solder at least 4 pins on each IC to hold them in place. The remaining pins can then be soldered. Remember, if you mess up the alignment at this point in construction, it can be extremely difficult to fix, so take your time to ensure there are no mistakes. Note that the DC ground for the amplifiers must come from the physical centre tap between the two filter caps. This should be a very solid connection (heavy gauge wire or a copper plate), with the transformer centre tap connected to one side, and the amplifier earth connections from the other. DC must be taken from the capacitors - never from the bridge rectifier.

The application of figure 5 shows the possibility of using only one command for both st-by and mute functions. On both the pins, the maximum applicable range corresponds to the operating supply voltage. A little blow circuit audio amplifier IC TDA7293 Note that the metal tab of the TDA7293 is connected to the -Ve supply, so must be insulated from the heatsink. The more care you take with the mounting arrangement the better. While you can use a screw through an insulating bush and a piece of mica to insulate the tab, a better alternative is to use a clamping bar of some kind. How you go about this depends a lot on your home workshop tools and abilities, but one arrangement I've found highly satisfactory is a suitable length of 6.25mm square solid steel bar. This is very strong, and allows good pressure on the mica (or Kapton) for maximum heat transfer. Naturally, heatsink compound is absolutely essential. DMOS, or double-diffused metal–oxide–semiconductor, output stagesare used in both of these audio chips. The TDA7293and TDA7294have maximum supply railsof +/-60V DC and +/-50V DC, respectively. Transformer supply railsare AC 32V-0-32V to 35V-0-35V, with 32V-0-32V being recommended for 8-ohm operation. Do not be tempted to use silicone insulation washers unless you are using the amp at very low supply voltages (no more than ±25V). The thermal transfer characteristics of silicone washers are not good enough to allow the amp to produce more than about 10 - 20W of music, and even that can be taxing for most silicone washers. The amp will shut down if it overheats, but that curtails one's listening enjoyment until it cools down again. The company offers a wide range of products including microcontrollers, sensors, power amplifiers, and integrated circuits for various applications in the automotive, industrial, and consumer markets.

TDA7293 vs TDA7294 Applications

If everything tests out as described, wire the amplifier directly to the power supply and finish off any internal wiring in the amp. Once complete, it’s ready to use. TDA7293 is the same conversion rate as TDA7294 ,however, it comes with a larger voltage supply range, and is the most powerful Dual 50 volt DC power supply which gives the user a greater dynamic range and greater output power. A load of 8 ohms with a 40V dual power source may generate an average power output of 100W. However, if the voltage is increased to 50V, or the load is decreased to 4 ohms, then the output power will rise, as per the TDA7293 specifications. Dual 28V AC voltage can be chosen when selecting an appropriate transformer, leading to an approximate 40V voltage after the rectification process and filtering. Of course, the voltage may be increased. Because of the variations of the gridvoltage, it is recommended to lower than 50V, which allows the circuit to function in a more stable manner.Today, easybom will introduce the differences between them to help you understand them.