hi, todays challangde 😉
i been measured at some point and i post the pic on my new website.
reward for solving this case... is a beer in oslo 😉
link to my site ..
nikotronic
somebody has a idea ?
this is connected without audio in and speaker at output.
Niklas
i been measured at some point and i post the pic on my new website.
reward for solving this case... is a beer in oslo 😉
link to my site ..
nikotronic
somebody has a idea ?
this is connected without audio in and speaker at output.
Niklas
Try a switch contact opening circuit at the resistor prior to pin 8 to un mute the amp. The information on page 17 of the LM3886 appears to me contradictory as supplying current to pin 8 would appear to mute the amp as you have done and NOT supplying current looks logical to me to unmute. Your schematic shows the pin connected via resistance to Vee where would follow to me that the amplifier is muted. Would not hurt to try.
Cheers / Chris
Check R6. It could be open. Blown like a fuse when the amp was first powered up.
The rail voltage is to high. +/- 42V is 84V which is the maximum voltage allowed.
Please post some photo's and the PCB layout.
The rail voltage is to high. +/- 42V is 84V which is the maximum voltage allowed.
Please post some photo's and the PCB layout.
The rail voltage was suggested by me also at post #2 as being too high, and 28+ and 28- was advised.
I thought it needed to be repeated as your good advice was ignored or not understood.
ok, thanks, I will buya new transformer and try again. 🙂
i will follow the adwise, it was not ignored but
on the specs its said Wide Supply Range 20V - 94V.
this is why.
i will follow the adwise, it was not ignored but
on the specs its said Wide Supply Range 20V - 94V.
this is why.
still havent connected speakers, because of the 42 volt output on speaker connection, first try on another module I burnt the speaker coil.....
but I see now that i have almost 92 volt total in voltage....
but I see now that i have almost 92 volt total in voltage....
the 84V to 94V spec if for NO SIGNAL conditions.
When signal is present the limit is 84V, i.e. in worst case conditions with some signal the supply must not exceed +-42Vdc, even when mains voltage is @ 10% above nominal value.
When mains is at nominal voltage (in Europe) of 230Vac, the supply must be <+-38Vdc.
When signal is present the limit is 84V, i.e. in worst case conditions with some signal the supply must not exceed +-42Vdc, even when mains voltage is @ 10% above nominal value.
When mains is at nominal voltage (in Europe) of 230Vac, the supply must be <+-38Vdc.
I realise that you have no speakers connected.
You should design the PSU to fit the speakers that will be connected.
Did you check R6?
You should design the PSU to fit the speakers that will be connected.
Did you check R6?
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ok, AndrewT, then it should not deliver -43 at speaker output with no signal connected because oof its 92 total voltage. 🙂
i will check tomorrow night, I am away this weekend, but I put a 2.2 ohm resistor as r6.
but will measure it tomorrow.
but will measure it tomorrow.
i was thinking here,, i guess i understand that the problem is at r6...
the overpass from signal ground to ground....
it said in the scematics that its should be 2.2 ohm, but in the parts list its 2.2 ohm....
I been reading about seperating signal ground to ground in som articles, som using low ohm resistance with a capacitor... i will say that i started with 2.2 in first build it burned opp, but i had a shourt in a line... so that explaind that, i changed in sekond build to 2.2 ohm...
I guess tomorrow that i will change the r6 to 2.2kohm.
the overpass from signal ground to ground....
it said in the scematics that its should be 2.2 ohm, but in the parts list its 2.2 ohm....
I been reading about seperating signal ground to ground in som articles, som using low ohm resistance with a capacitor... i will say that i started with 2.2 in first build it burned opp, but i had a shourt in a line... so that explaind that, i changed in sekond build to 2.2 ohm...
I guess tomorrow that i will change the r6 to 2.2kohm.
Page 3 of the manufacturers data provides Absolute maximum ratings, defined as
"Absolute Maximum ratings indicate limits beyond which damage to the device may occur"
and as Andrew points out anything beyond 42+/- is required to be No signal. It is sensible to abide by these recommendations. Also that distortion may be introduced from SPIKe Protection Circuitry if proper thermal considerations are not taken into account.
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