Hi all,
My NI Audio 2 DJ sound interface has an issue: whenever I rotate one of two volume knobs, I hear minor noise (rustling leaf sound) in speakers. I assume the root cause are worn out potentiometers.
I figured out they are from ALPS, the marking says MC 104C on the first one and MC 104A on the second one. See pics attached.
I'm not sure if I determined the model correctly. According to ALPS specs it is probably RK09 K12C F15 C0 ?104. Instead of the ? mark there should be a code for Resistance Taper. I guess it should be V, which means - 3B. However, I can see A and C letter on potentiometers, which could mean it is 15A and 15C respectively.
The only thing I am sure is to turn up the volume on chan A you need to rotate the knob clockwise but counterclockwise on the chan B.
Please suggest the correct model of those potentiometers and where I could order them.
Thanks!
My NI Audio 2 DJ sound interface has an issue: whenever I rotate one of two volume knobs, I hear minor noise (rustling leaf sound) in speakers. I assume the root cause are worn out potentiometers.
I figured out they are from ALPS, the marking says MC 104C on the first one and MC 104A on the second one. See pics attached.
I'm not sure if I determined the model correctly. According to ALPS specs it is probably RK09 K12C F15 C0 ?104. Instead of the ? mark there should be a code for Resistance Taper. I guess it should be V, which means - 3B. However, I can see A and C letter on potentiometers, which could mean it is 15A and 15C respectively.
The only thing I am sure is to turn up the volume on chan A you need to rotate the knob clockwise but counterclockwise on the chan B.
Please suggest the correct model of those potentiometers and where I could order them.
Thanks!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The markings A and C do refer to tapers. The 104 is 100,000k.
If they are simply used as volume controls then you might find a linear works OK (just with a different 'volume per degree of rotation' difference)
Couldn't find anyone stocking different tapers.
RK09K1130C94 ALPS, Rotary Potentiometer, 100 kohm, 50 mW, ± 20%, RK09 Series, 1 Turns, Linear | Farnell element14
If they are simply used as volume controls then you might find a linear works OK (just with a different 'volume per degree of rotation' difference)
Couldn't find anyone stocking different tapers.
RK09K1130C94 ALPS, Rotary Potentiometer, 100 kohm, 50 mW, ± 20%, RK09 Series, 1 Turns, Linear | Farnell element14
Hi JonSnell, it's out of warranty, not sure if the manufacturer will be interested in helping here. Though I'll try, thank you.
Hi Mooly, thanks for your suggestion, I think a linear pot wouldn't be a problem.
Still, it is hard to find it. The one you referred to is a single-unit and I need a dual-unit for my audio interface.
I'll keep searching for the proper one.
Please do ask the manufacturer if he can help, warranty has nothing to do with it. In the service industry we get our parts from those people whether for warranty repair or out of warranty.
Pots are a special item, in that unlike caps or transistors, they are almost always made to specifications for the OEM, in other words custom made. As opposed to finding the exact part on the shelf. You may get lucky and find the same part generically, but maybe not. The Alps catalog usually is just a reference for you to make up a part number for them to make for you.
So yours is a 9mm (looks like?) - measure the width of the body. The shaft is a D-shaft. the shaft has a length. If you can find a longer D-shaft pot, you can cut it to length. Looking at the legs, it looks like it might be a dual pot (stereo) And of course the resistance and taper.
Mooly's link looks to be a simple mono pot - not enough legs.
Note (as you did) that the two controls are on opposite sides, yet the + direction for both is the same way. That means that any taper other than linear will be reversed on one side. SO audio taper on one side and reverse audio on the other for example.
Linear might not be the taper, but if you make both linear, at least they will operate the same.
I think your guess at the part number is exactly right, and tapers A and C make sense, the data sheet here shows graphically the A and C as opposite tapers.
http://www.mouser.com/ds/2/15/RK09K-771158.pdf
But before any of that, rather than worn out pots - have you really turned those controls up and down tens of thousands of times? - I'd wager they might just need cleaning.
I don;t see any gaps in the plastic around the legs, but you might try squirting some Deoxit along the side of the shaft, while wiggling and turning the shaft. Usually that will allow some of the Deoxit to dribble into the interior. Then rotating the pot a few times spreads it around in there. What is there to lose by trying that?
Pots are a special item, in that unlike caps or transistors, they are almost always made to specifications for the OEM, in other words custom made. As opposed to finding the exact part on the shelf. You may get lucky and find the same part generically, but maybe not. The Alps catalog usually is just a reference for you to make up a part number for them to make for you.
So yours is a 9mm (looks like?) - measure the width of the body. The shaft is a D-shaft. the shaft has a length. If you can find a longer D-shaft pot, you can cut it to length. Looking at the legs, it looks like it might be a dual pot (stereo) And of course the resistance and taper.
Mooly's link looks to be a simple mono pot - not enough legs.
Note (as you did) that the two controls are on opposite sides, yet the + direction for both is the same way. That means that any taper other than linear will be reversed on one side. SO audio taper on one side and reverse audio on the other for example.
Linear might not be the taper, but if you make both linear, at least they will operate the same.
I think your guess at the part number is exactly right, and tapers A and C make sense, the data sheet here shows graphically the A and C as opposite tapers.
http://www.mouser.com/ds/2/15/RK09K-771158.pdf
But before any of that, rather than worn out pots - have you really turned those controls up and down tens of thousands of times? - I'd wager they might just need cleaning.
I don;t see any gaps in the plastic around the legs, but you might try squirting some Deoxit along the side of the shaft, while wiggling and turning the shaft. Usually that will allow some of the Deoxit to dribble into the interior. Then rotating the pot a few times spreads it around in there. What is there to lose by trying that?
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Pronidenis
Rustling sound can also be DC. Check if there are capacitors in signal path before or after the potentiometers. I had a same problem on a DJ controller headphone volume pot and cured it with 2 capacitors.
Rustling sound can also be DC. Check if there are capacitors in signal path before or after the potentiometers. I had a same problem on a DJ controller headphone volume pot and cured it with 2 capacitors.
Hey Enzo, MAAC0,
Thanks for your pieces of advice.
I've sent a request to the manufacturer, let's see if they can provide a circuit diagram and suggest on where I can find those pots.
Thanks for your pieces of advice.
I've sent a request to the manufacturer, let's see if they can provide a circuit diagram and suggest on where I can find those pots.
Silly Question ?
Have you already tried flushing out the Pots with Iso Alcohol?
Sometimes it's just accumulated wear debris
Have you already tried flushing out the Pots with Iso Alcohol?
Sometimes it's just accumulated wear debris
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