i made the bridged and parrelleled circuit last night (at last 
) and powered it up with +/-5v, as +/-4v is the lowest the chip will work with, and didnt want to damage anything if i had made a mistke.
powered it up, my 1A power supply overloaded (light came on), so i switched it off, re-checked every connection, all fine. re-power it up, still overload, shut it off again.
leaft the room, and had a cup of coffee. came back in, checked pin layout and circuit diagram of OPA541 and DRV134 (or is it DVR?), anyway, i noticed that i had missed the 'top view' on the OPA541 pinout. so i had connected the +v and -v connections backwards, and, less important, the + and - input backwards. doh!
desoldered all components, and started again. double checked all components, and again powered it up with +/-5v, nothing, no load, no output. i touched the input, no output (on my working gainclone i get buzz if i touch the input pin).
checked the speaker, i had blown it the first time, got a new speaker, conected it, powered it up again, still nothing. i disconceted power and the speaker and check voltages at the output, now +5v on both outputs. 
very iritating, could the chips be blown? with +/-5v? i may have accidentally turned the power supply up to +/-15v as when i came to power it up the second time, it was set to this.
thanks for any help, below i have posted a picture of my layout, sorry, it is very quick and messy, i am not on my own computer so i do not have images here.
oops, forgot, view is from below of chip,as i have them mounted on a heatsink and all i can see is the leads.
) and powered it up with +/-5v, as +/-4v is the lowest the chip will work with, and didnt want to damage anything if i had made a mistke.powered it up, my 1A power supply overloaded (light came on), so i switched it off, re-checked every connection, all fine. re-power it up, still overload, shut it off again.
leaft the room, and had a cup of coffee. came back in, checked pin layout and circuit diagram of OPA541 and DRV134 (or is it DVR?), anyway, i noticed that i had missed the 'top view' on the OPA541 pinout. so i had connected the +v and -v connections backwards, and, less important, the + and - input backwards. doh!
desoldered all components, and started again. double checked all components, and again powered it up with +/-5v, nothing, no load, no output. i touched the input, no output (on my working gainclone i get buzz if i touch the input pin).
checked the speaker, i had blown it the first time
, got a new speaker, conected it, powered it up again, still nothing. i disconceted power and the speaker and check voltages at the output, now +5v on both outputs. very iritating, could the chips be blown? with +/-5v? i may have accidentally turned the power supply up to +/-15v as when i came to power it up the second time, it was set to this.
thanks for any help, below i have posted a picture of my layout, sorry, it is very quick and messy, i am not on my own computer so i do not have images here.
oops, forgot, view is from below of chip,as i have them mounted on a heatsink and all i can see is the leads.
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pricy mistake...
I find that they are quite sensitive to ps mistakes and not only despite all those protection circuits.I must have burned 2-3 OPA 549 mainly from simple mistakes like yours.The other day I was just switching my pre on and off with a low vol and even though there was no thumps on the speakers I managed to burn another opa.Beats me why.Just change them , wire them up correctly and all will be well.No use trying to "pick up the pieces" here.
Hi!
Just btw.: Never touch the input pin (at least with no load connected). It will result in instant oscillations (which may be unhearable). And if you do not have a Zobel connected to output, you can damage the amp permanently (if you have a Zobel, the Zobel resistor will get very hot, probably melt).
I speak of experience, at least with P3A, and R. Elliot confirmed that this is the case with every amplifier which has no decent protection circuitry (and I find all internal protection circuits in ICAmps somewhat lacking, none has really protected me from faults, so far...)
So, be careful...
Bye,
Arndt
Matttcattt said:
Just btw.: Never touch the input pin (at least with no load connected). It will result in instant oscillations (which may be unhearable). And if you do not have a Zobel connected to output, you can damage the amp permanently (if you have a Zobel, the Zobel resistor will get very hot, probably melt).
I speak of experience, at least with P3A, and R. Elliot confirmed that this is the case with every amplifier which has no decent protection circuitry (and I find all internal protection circuits in ICAmps somewhat lacking, none has really protected me from faults, so far...)
So, be careful...
Bye,
Arndt
Re: Re: OPA541 blown?
i have no zobel and havemt heard any damage by touching the input, ill stop doing it anyway.
back to soldering, luckily i have 4 more chips to have another try, as i was going to make 2 channels. ill order more for the second and maybe some extra incase i blow these
Cradle22 said:
i have no zobel and havemt heard any damage by touching the input, ill stop doing it anyway.
back to soldering, luckily i have 4 more chips to have another try, as i was going to make 2 channels. ill order more for the second and maybe some extra incase i blow these
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