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SA-9800 Volume Control

BlueKatt

BlueKatt

Member
I need a new Volume Control for my SA-9800 amp. It is Pioneer part # ACW-119.

Of course Pioneer no longer has this part. Does anyone know of a source for this control or an acceptable substitute from another manufacturer?

EDIT:
I found this part at Mouser;

http://www.mouser.com/ProductDetail/ALPS/RK27112A00CC/?qs=vrbHPQ/MREj14Tk242DjZg==

Can anyone confirm if this will work?

Thanks!

BlueKatt


BTW...does anyone know the size of the set screws used to attach the knob to the control? I lost one and would like to find a replacement.

Volume Control
ALPS
ACW-119-A
043B-100K X2

vc12002.jpg


vc12001.jpg


vc12003.jpg
 
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Sorry for OT, maybe you could buy motorised blue Alps and enjoy a luxury of remote control?
 
The mouser part does not appear to have a loudness tap, as indicated on yours by 4 connections each wafer.

more later
 
The original is called alps black beauty but they are rare and pricey.

These are fairly easy to open so maybe you can fix this one? I opened mine without any trouble.
 
How was it determined that the pot needed to be replaced, no physical damage is showing.
 
markthefixer said:
How was it determined that the pot needed to be replaced, no physical damage is showing.
Click to expand...

Electronically the pot works fine. The problem is mechanical.

The pot no longer stops in the correct position. When you turn the pot down it travels beyond the correct stopping point and the brushes make contact with strip that allows a signal to pass through (almost sounds like both channels mixed together).

I took the back cover off of the pot and found that there is a lock that hold the shaft in place. It kind of looks like this;

speedwasher.jpg


The one on the shaft is much smaller than the ones shown in the picture and I don't know how to remove it without causing damage.

If you have an idea how I can take off the lock then I will be able remove the shaft and find out what is wrong with the stops.

Thanks!

BlueKatt
 
Thanks.

Mistreatment, that makes sense. Sad, but ...

You need to measure the original pot:
length, width height, row spacing between the wafers, pin spacing in the row, the MM outside diameter of the threaded shaft, and the length of the protruding shaft from the flat face of the pot.

The knob's little screw is 1.5mm

try for metric in the measurements,especially the shaft threads.

odds are that the pot will be obtained through eBay.
 
If you can't bend the flaps you can always pry the whole shim. You will probably need to replace it but if you take it really carefully you can manage to do it.
 
I will pull out the pot and get all of the dimensions. Then I will take a stab at removing the lock and see if I can get the pot apart. I will post pictures and info soon.

Thanks all!
 
condensing the thread, get the outer dimension of the shaft the push nut / lock goes onto, and we'll find replacements. I suspect it's smaller than 0.125".
 
I have one that I bought years ago, for a sx-1280, ACW-116-0, Alps black beauty (100Kx2), don't want to part with it sorry.
I do not see any difference, unless the tap R is different than -119, mine measures 13.6K from tap to ground or ccw pin, and 78.7K from tap to cw terminal.
So I am saying ACW-116-0, is a good sub.
1/4"(6mm) shaft diameter,18mm shaft length,3/8"(9mm) threaded shaft,anti-rotation key,10mm from shaft center.
 
Took the pot partially apart last night, Here are a few pics;

vc1s.jpg


vc2s.jpg



I was able to get the push nut off without damage so I think I can reuse it;

vc3s.jpg


Here is the detent and stop;

vc4s.jpg



If you notice, the detent plate is loose. It is supposed to be staked to the shaft. It looks like someone tried to remove the volume knob without removing the set screws. They pulled on the shaft hard enough to push the detent plate off of its mount on the shaft. I will try to remount the plate and re-stake it.

Since these pictures were taken I have desolder the pot from the board. Once I re-stake and grease the detent plate I will clean the wipers and reassemble the pot. I have good reason to expect I will be able to save this pot.

More to come.....
 
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SUCCESS!!

I was able to rebuild the pot and get everything working as it should. Here is how it went;

View of the pot shaft and front plate

vpr1.jpg


Shaft lubed and installed. Detent plate installed and lubed.


vpr2.jpg


There was not enough material on the shaft to stake on the detent plate so I installed a brass collar over the shaft and held it in place with a set screw. The collar is a part I normally use for RC airplanes. It's a perfect fit. No matter what gorilla might come along in the future the detent plate will never come loose again!

vpr3.jpg


Now install the front plate to its housing

vpr4.jpg


Followed by the resistor element and wiper

vpr5.jpg


vpr6.jpg


Now the middle housing, second resistor element and wiper


vpr7.jpg


vpr8.jpg


vpr9.jpg


Then install the push nut

vpr10.jpg


And finally, installed the last housing/back cover and screws. All done!

vpr11.jpg



I soldered the circuit board back onto the pot and reinstalled it into the unit. Operation is now perfect!!

BlueKatt




 
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I have an SA-8800 with the same problem. When I got it, the volume knob was stuck on the shaft, and someone thought they could turn it against the stop and break it loose. All they succeeded in doing was breaking the stop. I got the knob off, and have been watching ebay for a couple of years waiting for an ACW-113 to come up, no luck so far. Good luck
 
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