TDA7297 Works on AC but not DC ??

[scott67]

I bought two of these off ebay for $6 and two more from a different vendor. All 4 work when connecting Ac output PS but no blue light with DC voltages from 9 to 15 even though they are marketed as Ac/Dc 12v. I made sure the polarity connections are correct. I didn't want to try reversing them but for $3 maybe I should try? Any thoughts on this? Thanks

 

[irribeo]

less than lunch thread

Matt, watch out for the mis-marked polarity on the $3 ones. If you feed it ac it doesn't matter, of course.

Will respond to your other comments and questions a little later...

 

[scott67]

Solved - that was it

Thanks - I was concerned to reverse the leads but it worked - also, I had tried 6 to 16 volts the way the board said (which is wrongly marked) and it did not damage the amp.)

 

[phase]

Yup, I discovered that on mine before I put power to it while I was planning out some mods...
Amazing engineering there.

 

[cogitech]

Scott,

Yes, running DC to it as marked on the board does not kill it. However, I had my miniDSP feeding the amp during testing and fried two of the transistors on the miniDSP outputs.

Lesson learned.