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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. For safety reasons, the 0V wire of the transformer should be connected to the metal case which is indirectly the earth of the power main connector. There is a possibility to introduce a ground loop (and high current) when signal ground is connected to the main earth and for this reason there is a common protection network needed which consists of: The speaker return should be made directly to the centre-tap of the power supply filter capacitors, despite the fact that the PCB has a ground padfor the speaker. The pad on thePCBis a 'convenience' that allows PCB connectorsto be used (as shown in the photo above). These should only be used if the connection to the power supplyis very short (less than 100mm).
Symmetrical source, mount 2.1. Printed circuit board PCB suggestion for 2.1 amplifier assembly with tda7294 2.1 tda7293 2.1 Tda7294 2.1 Tda7293 2.1 Power Amplifier Pcb Component View Tda7294 2.1 Tda7293 2.1 Power Amplifier Pcb Top Tda7294 2.1 Tda7293 2.1 Power Amplifier Pcb Bottom Tda7294 2.1 Tda7293 2.1 Power Amplifier Pcb Top Overlay BOM for mounting or amplifier 2.1 You may be a lateral mosfet fan like me, or you might be surprised that many people had preferred a 3886 based amp compared to a sophisticated discrete lateral fet amp. That's why I have always emphasized this "taste/preference" issue.If you want to know how 7293 will perform in comparison to 3886, you have to know how mosfet amps sound in general, then you could benchmark the 7293 with another mosfet amp (where they have similar characteristics in sound). I'll bet 80% at least will prefer 3886. The on-board rectifier brides are no longer needed as it is replaced with D3. For this reason I shortened the on-board rectifiers which is easier than desoldering. Solder wires (red lines) as shown in the picture below. Switching power supplies are very welcome as well but they need to be able to provide low noise and ripple. The Meanwell LRS series is a very reasonable choice but you need to combine two of them to get ±Vss. 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.
Tda7293 In Parallel Schematic Circuit PCB TDA7293 in parallel Audio Power Amplifier Modular Tda7293 Board Bottom Audio Power Amplifier Modular Tda7293 Board Silk Audio Power Amplifier Modular Tda7293 Board Top Audio Power Amplifier Modular Tda7293 Board Component View Item Nº. Before discussing the results, I’m going to say in advance that the characteristic sound of TDA7293/94 and listening fatigue have both gone. That simple design has turned TDA7293/94 into a real HI-End amplifier successfully competing with many famous (including the price tag) power amplifiers. For more information look at the section of Sound Quality.My last hope are now the great people in this forum who might be able to help me figuring out, what the problem with my amplifier design is. 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.
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