2. tech-talk
  3. 123919-78909

Pop/crack on power up, followed by audible tweeter hiss

Hey there, looking for a little advice before throwing money at this issue. I recently installed an integrated amp (nuprime ida-8) in my 2.1 system. When I power up the amp I get a pretty loud pop/crack noise from the speakers followed by a hissing noise from the tweeters that's quite obvious near the speaker and just audible from my listening position. This happens regardless of input, mute toggling, and is independent of the volume level. The amp is plugged directly into the wall (tried multiple outlets). I've been googling, and ruled out some things:

-Disconnected everything on the amp other than power and the l/r speakers
-Unplugged everything else in the house, shut lights off etc
-Made sure the speaker wires weren't touching anything
-Tried two different amplifier units
-Tried 'cheater' plug on the amp power cord

None of this had any effect. Previously I had a pure class-d integrated for a time that was dead silent. I'm in a fairly old apartment building so I don't have any control over the wiring. Is the next step to think about power conditioners or some other device? Any input appreciated. Thanks. 
artishard116
georgehifi's avatar
georgehifi
10,312 posts
 

Not normal for all Class D's (  it depends on filter cutoff frequency), but some that I have had experience with yes.

And for yours I can't tell unless I had it on the test bench, but it sure sounds like it, as what you describe has all the hall marks.


Cheers George

artishard116 OP
4 posts
 
Good to know, thank you. 
minorl
1,016 posts
 

I don't believe that the noises, pops, etc. on startup are normal at all.

I would at the very least contact the manufacturer and find out from them it they believe this is normal or not and start from there.

get it checked out.

enjoy

georgehifi's avatar
georgehifi
10,312 posts
 

Read first two paragraphs and there's plenty more on other brands as well, and this explanation is quite a bit watered down as well.

http://www.6moons.com/audioreviews/nuforce2/9_2.html


Cheers George

meerzistar
232 posts
 
One of my aging Canadian class D amps sounds pretty rude upon powering up and down. It sounds perfectly well other than at those times. I had a hunch discharging caps might be the cause at power off, it does an almost typical sounding "pop" but its accompanied by harsh static or crackle. Ive grown used to with other amps that went on working well into the future. Never had one make a noise during power up, and its not a pop Im not even sure how to describe it other than brief and nasty. Im tempted to buy new caps and wire them in and take a blind crack at it anyway to see what happens.   
More to discover