开云体育

Summary:? All is well, unless you have a WX branded TDA2822.


Here's an old post regarding the TDA2822, many other posts in that thread worth browsing:
? ??/g/BITX20/message/43342

Yes, the TDA2822D is still available from ST, would be a good choice
if you don't mind?the 50 mil pin spacing.? ?I'd stick with the NJM2073.

There was a lot of guessing in the forum when the WX clone chips first started blowing.
Many of the WX chips blew when somebody first plugged something into the headphone jack,
that seemed to put them over the edge. And some blew when first powered up.
But I don't think anything other than a WX chip ever blew.

Most of the TDA2822 datasheets spec a max operating voltage of 15v.
The UTC clone (never used by hfsignals) gives a max operating voltage of 12v, but does say it will survive 15v.
The WX clone does not have a datasheet, reports show it?can blow if they see more than 6 or 8 volts.
A power up event or plugging in headphones can be what puts them over the edge and causes them to smoke.
If you still have a WX chip, I suggest you either swap it out or add a voltage regulator to it as per?
? ??

That page suggests brands other than WX can blow when the output is shorted.
I don't recall any such reports in the forum, let me know if anybody can find such a report.

All of the datasheets specify distortion levels and power out as a function of supply voltage,
these tables typically top out at 9v or so.? ?So we don't know what the harmonic distortion is at 12v,
but that is well under the 15v maximum operating voltage.

All except the WX operate fine at 12v, my only concern would be that the chip might overheat when
driving a low impedance load (such as a short or a 4 ohm speaker) with?the volume turned up high.?
If the chip is not too hot to hold our finger on it, all is well.?
A momentary short would not give it enough time to overheat.?
?
Jerry, KE7ER