anybody did the analogical circuit?

[bigcatdairy]

hey everybody!

did anyone here make a simular circuit as link below?
??TDA7294?????????????????-????-???????

recently i would like to build an amp on 200~300W/channel and i will choose one of the following solution for this project:

1 circuit as link above;
2 parallel btl tda7293, probably 2~3 ics parallel.

can anyone tell me which one worth more to do since a little shortage in fund that i can't build both.

thanks.

[AndrewT]

I can't read the text, but I would not trust that link with my life.

1pair of 1943/5200 is worth about 60W of maximum output power into a severe reactance speaker when used for domestic duty.

If you can't tell what was wrong with that schematic then you should not be considering any of the multi-chipamp offerings that abound and await beginners to blow up all their attempts to copy.

[bigcatdairy]

i can read the text but sorry about can't translate.

really, i can't tell what was wrong with that schematic, just need to build up an easy high power amp for continuing my loudspeaker project.

so does anyone can offer me a scheme of a parallel bridged 7293?
thanks.

[tawen_mei]

With +/- 40V you can't get 400W into 8Ω load. The output stage bias looks wrong, too. There are 6 VBE between the two bases. If it works, it's because the 22K resistor is limiting the base current, and the beta of the output BJT isn't very high.

[panson_hk]

Originally Posted by AndrewT

I can't read the text, but I would not trust that link with my life.

1pair of 1943/5200 is worth about 60W of maximum output power into a severe reactance speaker when used for domestic duty.

If you can't tell what was wrong with that schematic then you should not be considering any of the multi-chipamp offerings that abound and await beginners to blow up all their attempts to copy.

The text says this is a TDA7294 based high-power amp with tube sound. TDA7294 is selected due to its fully FET structure which produces tube liked sound. The limitation in output power is overcome by using external output devices. The text says 400 W output power is possible.

As tawen_mei mentioned we won't get 400 W 8 Ohms from +/- 40 V rails.

[bigcatdairy]

so, how to parallel 3pcs of 7293??
who can give me a circuit or a like of where to find?

[pacificblue]

Originally Posted by bigcatdairy

so, how to parallel 3pcs of 7293??
who can give me a circuit or a like of where to find?

You can find it in the datasheet. Just add another slave to the "Modular Application Circuit"

More TDA7293s in parallel won't increase the power output into 8 Ohm. You will need to go bridge-paralleled. Bridging is shown in the TDA7294 datasheet. Put the two circuits together on your own. If you cannot do that, you'd rather leave your hands off such a project.

[panson_hk]

I am going to experiment TDA7293 parallel/bridge. Got chips and a board from TaoBao for mods.

[abraxalito]

Great I'm looking forward to how the results from that compare with those you've presented for the LM3886. Especially of interest is the LF response as those chips use capacitor bootstraps - a major difference with the 3886.

[bigcatdairy]

Originally Posted by pacificblue

You can find it in the datasheet. Just add another slave to the "Modular Application Circuit"

More TDA7293s in parallel won't increase the power output into 8 Ohm. You will need to go bridge-paralleled. Bridging is shown in the TDA7294 datasheet. Put the two circuits together on your own. If you cannot do that, you'd rather leave your hands off such a project.

i think i had found, thanks.