2350 chip blown

[mash.m]

hello,

at the long weekend i startet to build my amp 2. after solder all components i have checked it twice. first run only 5 volt on the chipset. all ok, current ok too. then checked my powersupply twice and fuse it. at free run i have 58 volt. after powering up my amp 2 make a short noise and a little smelt was in the air. ok, checking my power supply - all ok. check the devices on the board, and i only see that the two inductors L10 and L3 are mixed up!
is that possible that the tripath chipset is blow cause the inductors are mixed ?

here you can see:

http://spidermeel.homeip.net/temp/vorne.jpg

and

http://spidermeel.homeip.net/temp/hinten.jpg

i have just ordered a new chipset for my amp...

markus

[aleka]

I did exactly the same thing to mine. The reason explained by Jan was the voltage of the Power Supply. Check out this post

http://www.41hz.com/forums/topic.asp?TOPIC_ID=1115

Rather then buying another expensive Transformer I just took a few windings off the one I had...Might work for you...

[Mr T]

May be should you use bleeders in the PSU to somehow "stabilize" it and avoid peaks when amp is idling ?

Have a look here : http://www.41hz.com/Forums/topic.asp?TOPIC_ID=1116 and here http://www.41hz.com/Forums/topic.asp?TOPIC_ID=1257

Mr T

[aleka]

Yeh I added the bleed resistors and lowered the voltage to 50v. Don't want to fry another chip, although after destroying an AMP2 I got the new truepath and used the same 'modified' power supply.

The only problem was I managed to get the VNN & VDD swaped and killed the chip again. So now I have an AMP2 & Truepath both dead from that powersupply, well one was my mistake, actually both where.

I've built 4 AMP5's and all of them are perfect, so my sub's gunna stay a bit quiet until I learn to 'rtfm' and stop blowing up chips.

[mash.m]

hello,

jan wrote at a other post:

__________________________________________________ _____________
Are the 61V calculated or measured? Bad case scenario for a 45VAC transformer:
- 45VAC=> 45*1.41=63.45V
- Tolerance in transformer rating 5% => 66V
- Mains power voltage variation 2% => 67V
- At low power, rectifier diode drop is low, say 0.5V => 66.5V
- Voltage increase in transformer at idle compared to specified full load voltage, 5% => 69.8V
- Overshoots in the PCB due to switching current into trace inductances and output filter inductance, 5V => 75V
Pooof!
So you really need to measure the real voltage and allow for the uncertains.
__________________________________________________ _____________
i don´t understand the following:
- Overshoots in the PCB due to switching current into trace inductances and output filter inductance, 5V => 75V
Pooof!

can anybody describe this phrase ?

my transformer have 45 volt original. then taken 13 winding so the voltage is 58 volt without load after the rectifire with some small 2200uF caps.
i have messured the voltage from my power supply with a multimeter and a oszi. all is at the green and under 60 volt without load.
i don´t understand why the chip blow in a few msec. when you have a overvoltage of a few volts the chip will get hot and smell, but not shoot out ?!?
what do you think about the mixed inductor ?

markus