Help Me Diagnose Audio Problem (1 Viewer)

[BrettB]

Wasn't sure where to post this as I'm not sure what's causing it?
Typical scenario: movie ends and credits start, turn down the volume from ref. or near ref. level, notice nasty crackly sort of sound (high freq.) from front left speaker as I'm turning down the volume. Haven't noticed it on CDs but I haven't cranked any CDs lately.
Do I need some of the stuff that you spray on the metal stem of the volume control? Seems odd that it's only on the front left channel.
FYI:
Sony DA333ES receiver (still under warranty)
Boston Acoustics Speakers
Any help diagnosing this will be much appreciated.

 

[RichardMA]

If the potentiometer (volume control) is an old analog
unit, you might have to have it cleaned. Take it in
for service. If it's digital, then something else is wrong.

 

[Walt N]

I've had that problem many times with both home audio and pro sound equipment. Chances are you have a dirty or burnt potentiometer behind the volume knob. With one old Kenwood receiver I have this problem develops every year or so and I can fix it for another year simply by vigorously twisting the knob back and forth a bunch of times (with the power off.) This redistributes the grease that's in there and it's good to go. For other pieces of equipment I've had to pull the knob off and spray some Rat Shack TV tuner spray and lubricant in there next to the post and they were OK after that. WD-40 works quite well in a pinch.

 

[Chuck Kent]

If it was mine, I'd take it in for service. It may violate the warranty if you do anything to the unit.

(If you do decide to try spraying something into the unit yourself, there are differences in potentiometer cleaners. Radio Shack sells a professional grade cleaner for $7.95 called Caig Laboratories DeOxit (#910-3879.) It can be ordered via phone, internet or at the store. I would not consider using anything else.)

 

[Walt N]

If De-Oxit lubricates I'm sure it would be fine. Otherwise I'd use this stuff. It's very similar to WD-40.
Better yet, as you are still under warranty (sorry, didn't catch that before) I'd exchange the unit. A bad potentiometer at this early stage of the game is probably not messing with if you can let them resolve it.

 

[BrettB]

Thanks for the replies guys. Walt, I'll try your suggestion first (quickly turning knob back & forth) and see what happens. Why is it only on the left front? Seems like it would affect all channels.

 

[Gerard Martin]

BrettB
Have you switched your left and right front speakers to eliminate the possibility of a left speaker problem, if so agree with Walt if its still under warranty let Sony solve the problem. Call Sony Customer Service at 1 800 222 7669 explain the problem and see if they have a solution, if not ask for a work order number and the nearest Sony Service Center that repairs your model receiver. Hard to believe twisting volume control knob would effect one speaker.

 

[Walt N]

Each channel has a seperate contact points which can cause trouble individually. With my Kenwood it's only the right front channel that goes haywire.