AU-517, sound from one speaker before the other

Curse

Curse

Old Uncle Thingy
Hello again all, I've been mostly absent from these parts for quite a while due mostly to boring medical issues and lack of time.

As ever, they always come back when they have a question :D

So here it is - my '517 will produce sound from one speaker before the other when coming up from zero volume, and there is a light crackle at first. Once I get a click or two up the scale, both speakers will be putting out sound, and all will be well, no crackling at all. All other controls are noise free.

The question is, could there be any possibility of damage to the speakers in this situation?

The amp had a full recap (except main filters) and clean a few years ago, so all should be well in that department.

Thanks, and I hope I've explained this reasonably!

Dan
 
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The cure would be slacken off volume pot screws/bolts just enough to be able to spray DeOxit into the crack, use DeOxit, - work the pot - leave for a while, follow up with DeOxit Faderlube and it should be good to go. However, it could be a mechanical problem with the synchronisation of the pot sliders :scratch2:

If this doesn't solve it then taking the pot apart to clean more thoroughly might be the answer, otherwise replacement ALPS pot seems to be the only other viable alternative.

BTW: I did the re-cap, and at the time there was no issue with the volume control, so I left well enough alone :sigh:
 
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Same issue here with a triple seven - it was strictly mechanical, as John says, one slider engaging before the other. This pot was from 69, and seemed pretty crude. I could actually see one side ahead of the other and managed to turn the shaft open slowly while holding back the "ahead" slider with the tip of a plastic screwdriver. Gentle gentle process, yet I ended up slightly reversing the problem :sigh: I wouldn't worry about, just give it a thorough clean.
 
Thank you, I shall have a go at that, but need to get some Faderlube.

John, the amp in general is still performing wonderfully, just that *initial* crackle and audio from one speaker, then as I click through a couple of notches on the volume it disappears immediately.

Cheers for your input!

Dan

ps I can't seem to send private messages at all at present, I will renew my suubscription on pay day!
 
you could first try rotating the vol 20/30 times to see if it cleans itself up .
do this with it switched off .
 
The thing is, I've done quite a fair bit of pot cleaning before; for some reason I didn't even consider it in this instance...

We shall have to have a look see :yes:

cheers

D
 
Curse said:
The thing is, I've done quite a fair bit of pot cleaning before; for some reason I didn't even consider it in this instance...

We shall have to have a look see :yes:

cheers

D
Click to expand...

I hope you are aware that this is a closed (sealed) pot.
As you have to drill or open the housing there are some riscs involved damaging the pot. Instructions can be found here on AK.

Therefore I leave mine alone as long as possible (has the same issues as yours).

Good luck with a great amp.

-John-
 
jd-audio said:
I hope you are aware that this is a closed (sealed) pot.
As you have to drill or open the housing there are some riscs involved damaging the pot. Instructions can be found here on AK.

Therefore I leave mine alone as long as possible (has the same issues as yours).

Good luck with a great amp.

-John-
Click to expand...

It can be difficult to DeOx this pot, but not impossible. I found on mine that there are just the smallest openings on the bottom of the pot, and can be accessed by taking off the bottom plate. By using the red straw attachment and some careful positioning you can force some DeOxit into the pot. Most of it will end up wasted as these holes are much smaller than the red straw attachment. This worked well for my AU-517.

If this does not work, you can still get at it without drilling. If you use a soldering iron with a tip that you don't mind ruining, or a woodburning tool, etc, you can melt a hole in the plastic body of the pot. This prevents any small plastic particulates from the drilling process from causing any problems in the pot.
 
Hopefully Deoxit will cure your issues. You stated that the unit was recapped. Was it adjusted after the recap?

But again, go the Deoxit route first.
 
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