Amp PSU Pops

[Tenson]

Hi guys,

I have built an amp that seems to work well, however every couple of hours I seem to get a random loud pop from the speakers.

I haven't noticed this when running a 25V transformer, but I do when using a 30V one. The PSU smoothing caps are rated at 50V so the rectified 30V comes pretty close at ~46V. It is difficult to fit higher voltage rated caps due to size limits.

What is the cause of this? I thought maybe the caps are building up and then leaking all of a sudden into the circuit? If so, is it possible to put a couple of high value (?R) resistors across each cap?

Thanks!

[sakis]

not especially a power supply issue eventhough could be

any of the parts of your amplifier overheating from wrong calculation or missplacement

state more about the amp ...pictures also might help .... and a soldering check might also bring something up

kind regards sakis

[!]

Have any other equipment with motors on this mains AC circuit, perhaps an air conditioner/etc. is kicking off creating a surge?

[sakis]

yeap !!! also a very good posibility ...sorry i missed that

[AudioSan]

Originally Posted by Tenson

Hi guys,

I have built an amp that seems to work well, however every couple of hours I seem to get a random loud pop from the speakers.

I haven't noticed this when running a 25V transformer, but I do when using a 30V one. The PSU smoothing caps are rated at 50V so the rectified 30V comes pretty close at ~46V. It is difficult to fit higher voltage rated caps due to size limits.

What is the cause of this? I thought maybe the caps are building up and then leaking all of a sudden into the circuit? If so, is it possible to put a couple of high value (?R) resistors across each cap?

Thanks!

how is the VA for the transformers?

[!]

Originally Posted by Tenson

The PSU smoothing caps are rated at 50V so the rectified 30V comes pretty close at ~46V. It is difficult to fit higher voltage rated caps due to size limits.

... I thought maybe the caps are building up and then leaking all of a sudden into the circuit? If so, is it possible to put a couple of high value (?R) resistors across each cap?

Thanks!

Running 50V caps at 46V would not account for this. They will build up a charge only to their uF value and should not be a problem, would not cause the amp popping.

High value resistors would not be expected to solve this, although having them as bleeder resistors so the caps drain to a low level more quickly when the amp is turned off can be useful if the amp doesn't have a mute function, and for safety in case someone were to be working with the power supply components and didn't want a charge still in the capacitors.