Cleaned volume control pot, system sounds better now, I'm crazy right??

[Ess El Emm]

The volume pot on my Onkyo P-308 preamp has been pretty bad for a while now. There were definitely times where if you had the volume knob at the wrong spot, one channel would drop out or get much quieter. There was audible static from the speakers when turning it through a certain range as well. I wasn't fully sure how to get inside the pot to clean it, but I took the time to do it this morning.

I had to remove a set screw to get the volume knob off, remove a nut on the shaft of the pot, then open up the preamp itself, pull the pot out to where I could access it, remove two long screws holding the pot together, and finally pull it apart just enough to squirt some contact cleaner in it.

Anyway, now that I've done that, the knob moves much more smoothly, and there's no static or channel drop out, but I swear that the sound quality itself is just a little better... The highs seem clearer, the bass seems fuller. Could this really made that much of a difference? I guess I didn't expect it to improve anything beyond fixing my channels dropping out and a little static when moving the knobs sometimes. And I'm still not sure if this might be just a placebo effect.

 

[JoeESP9]

It's not the placebo effect. Cleaning a static prone volume control that sometimes drops a channel will almost always result in better sound. A dirty pot can and does cause a loss of fidelity that isn't easily audible until you do an A B comparison or fix the pot.

 

[awillia6]

It's not the placebo effect. Cleaning a static prone volume control that sometimes drops a channel will almost always result in better sound. A dirty pot can and does cause a loss of fidelity that isn't easily audible until you do an A B comparison or fix the pot.

Serious question: what's the mechanism of the degraded sound caused by the iffy volume control (once it's set at a given level)? High or varying resistance even though the pot position isn't changing? Micro-arcing or something like that?

 

[Splatter Pak]

I was getting some very odd noises out of my computer system, and I blamed it on a new computer & OS (Transsource + Ubuntu). The amp I was using was a Yamaha M-35, and I decided to clean the pots. It was easily done, much more so than the OP describes for his gear, and once back in the system, all the odd noises were GONE! I think sound quality is better too.

 

[Ken Boyd]

Just Crazy.

 

[N8Nagel]

Not crazy at all. If there was dirt or oxidation in there even when it seemed to be working correctly there might have been a channel imbalance that you've now fixed.

 

[jobrewer1983]

Good Job,

You should try to clean every pot/switch on the preamp, and if your amp has a few buttons hit those as well. It's always good to keep the system clean.

And no you are not crazy, cleaning controlls usually do make a noticanble sonic difference.

Again good Job!

Kind Regards,
John

 

[DaveVoorhis]

Serious question: what's the mechanism of the degraded sound caused by the iffy volume control (once it's set at a given level)? High or varying resistance even though the pot position isn't changing? Micro-arcing or something like that?

Sure, that and the channels being out of balance.

Or it might be the same mechanism that makes your car run better after you've washed it.

 

[ev13wt]

The volume pot on my Onkyo P-308 preamp has been pretty bad for a while now. There were definitely times where if you had the volume knob at the wrong spot, one channel would drop out or get much quieter. There was audible static from the speakers when turning it through a certain range as well. I wasn't fully sure how to get inside the pot to clean it, but I took the time to do it this morning.

I had to remove a set screw to get the volume knob off, remove a nut on the shaft of the pot, then open up the preamp itself, pull the pot out to where I could access it, remove two long screws holding the pot together, and finally pull it apart just enough to squirt some contact cleaner in it.

Anyway, now that I've done that, the knob moves much more smoothly, and there's no static or channel drop out, but I swear that the sound quality itself is just a little better... The highs seem clearer, the bass seems fuller. Could this really made that much of a difference? I guess I didn't expect it to improve anything beyond fixing my channels dropping out and a little static when moving the knobs sometimes. And I'm still not sure if this might be just a placebo effect.

This is the small differences that are noticeable with old gear such as yours or mine. Regular maintenance will get you much further than any "mod". Its not only the volume pot, its every switch where a signal is sent through.