crackling noise that goes away when volume is upped?q

[Roman-dude]

Hi, I have this problem that sometimes the sound starts to crackle up and disappear. The problem could be rectified by either jacking up the volume and then lowering it or by changing the channel and then returning to the original one. I used to think that a cable box might have been to blame, but 1. that's been replaced and 2. it also happens when I use netflix streaming, so it seems that it can't be that. This leaves the amp and the pre-amp as the main suspects (I have a Sherbourn 5/1500A amp and a Denon AVP-8000 preamp). Also, it never happens when I play SACD disks, though those run through analog outputs, not via the optical as when the TV is on.

Anyway, does anyone have any idea of what this might be? Thanks.

 

[KEW]

Usually with this type of behavior, there is a bad connection. It takes a stronger signal to "break through" or "arc across" the bad connection. Once the connection is established, it will continue to a lower level than was required to initiate it.

Usually we are talking corrosion or dirt on contacts, but a poor spring pressure on contacts can "help out" as well.

The fact that your SACD is immune to this problem suggests that it has to be upstream of the first component common o the SACD and whatever sources have the problem. I would assume that the SACD plugs into your pre. If this is the case try plugging one of he "bad" sources into the inputs used by the SACD and see if that clears it up. If so, the problem is likely at the source selector contacts.

Your post is not clear about what components have trouble. Does the problem only occur with digital (optical) inputs?

 

[Roman-dude]

KEW, thanks for the reply. Skipping over to your last question - that's exactly my question - I'm trying to figure out which component's at fault. The set up is as follows - a separate DVD (that streams netflix) via optical into pre, a cable box via optical into pre (I used it with a coax before and the problem was still there), and a SACD player via analog into pre. Al three obviously into three different inputs. The problem occurs with the first and the second, but not the last, which inclines me to blame the pre (since the amp is common in all three cases), in particular its digital processor (??). But I'm no pro at this, so wanted to see if it makes sense or if there likely to be alternative explanations.

thanks again!

 

[KEW]

I'm not too experienced with this, but the behavior you describe (having to turn up the signal before it kicks in) is very much analog in nature. In the digital domain, a louder signal is not a stronger signal (just different digital code).

 

[Roman-dude]

now you got me more puzzled than before, because all the connections when this happens are definitely digital... thanks anyway.

 

[KEW]

now you got me more puzzled than before, because all the connections when this happens are definitely digital... thanks anyway.

Just in case it is not clear, the problem is in the preamp.

The fact that everything works and (I presume) sounds fine once the volume is up means that it is probably worthwhile to have it repaired (unless you are looking for an excuse to replace it).

 

[Roman-dude]

Just in case it is not clear, the problem is in the preamp.

The fact that everything works and (I presume) sounds fine once the volume is up means that it is probably worthwhile to have it repaired (unless you are looking for an excuse to replace it).

lol you hit the nail on its head.. considering that the pre is probably around 20yo, though I did have it in a closet for a big chunk of that time, makes me think that a replacement would be a better option.. thx