Defective Knobs

  • I've had my Kemper Stage since November 2022. Since the day I got it the two left knobs under the display (in between the Gain and Master Volume) have been very faulty, as in unpredictable and impossible to fine tune (jumping all over the place) even when not touching them, they will adjust. I just ignored this since I can bypass that and use the PC Rig Manager.

    After procrastinating for too long, I finally decided to figure this out since I won't always be able to have access to the Rig Manager.

    Today I tried to use electrical cleaner because I thought dust or dirt would be the problem.

    Unfortunately, the problem persists.


    What solutions are there to fix this?

  • BTW, Deoxit won't work right away unless you turn the knobs back and forth dozens and dozens of times to loosen stubborn dirt ands grit. And then you may have to give it a second blast. But pots do wear down and create gaps on the contacts in which they need replacement.

    Larry Mar @ Lonegun Studios. Neither one famous yet.

  • "Deoxit" or Oxide Cleaner wont help at all because these are not "regular" pots, they are digital encoders

    that turns endlessly in both directions unlike regular pots that stops at less than one rev. :/


    Cheers !

    The adjective for metal is metallic. But not so for iron ... which is ironic.

  • "Deoxit" or Oxide Cleaner wont help at all because these are not "regular" pots, they are digital encoders

    that turns endlessly in both directions unlike regular pots that stops at less than one rev. :/


    Cheers !

    Looks like they both have contact points using a "wiper" system that can get dirty...


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    Larry Mar @ Lonegun Studios. Neither one famous yet.

  • On the RME forum defective rotary knobs have come up from time to time.


    Mattias Carstens who is very knowledgeable and very honest about equipment problems, stated that whilst most people imagine problems with rotary knobs occur because of plenty of use, that normally is not the case.


    He said that most problems with rotary knobs actually occur because of insufficient use. Presumably oxidation on contacts weakening signal where over time they haven’t experienced enough use.


    So, any equipment I have that uses rotary controls (and gear that uses regular potentiometers) are sure to have a turn or two, whenever convenient, especially as most of my gear is in store.


    I consider the trouble it takes to do this to be standard operating procedure and regular preventative maintenance, with an annual plan.


    As I result I have yet to have ever needed to change a faulty potentiometer or had a problem with a rotary control.


    That’s over 57 years.

  • Sorry, but that's a failure in logic. Correlation and causation are not the same thing. And anectdotal evidence is just...well anectdotal. You may be a statistical outlier, but that's all.


    I have serviced and built many(too many to count) tube amps over the years. I have experienced many pot failures and they fail for many different reasons. Giving a knob a twist is not a guarantee that a pot will not fail. While exercising the wiper across the track can be helpful in certain circumstances, it is not a panacea. I've had many high use pots fail and high use is in fact a failure mode for many pots. Dragging a metal contact against a softer conductive surface will eventually lead to problems.


    I don't know what kind of rotary encoder is being used in the Kemper, but there are different types. The video linked above is incomplete and describes only one type. Without knowing what type you have, shooting a liquid 'cleaner' into the device may or may not be a good idea. Perhaps Kemper could recommend something beyond filing a ticket.


    BTW, this thread does have a comment from Kemper

    Pots working erratically. Would Deoxit fix the problem? - Profiler related issues and trouble shooting help - Kemper Profiler Forum (kemper-amps.com)

    Edited 3 times, last by lbieber ().

  • Quote: “Sorry, but that's a failure in logic.


    No need to be sorry, thank you for your singular viewpoint.


    Happily, it’s not my personal logic that is being called into question but someone far more knowledgeable.


    However, when I started in the music business, we had a large repair department, and cleaning pots and turning them thereafter was a regular occurrence by the fifteen white coated bods, some of which worked for the BBC.



    Quote: “anecdotal evidence is just...well anectdotal. You may be a statistical outlier, but that's all.



    With respect, apart from the moderators, each and every singular contribution to this forum, including that of yourself could be considered anecdotal. It simply means the view of one person.


    But I am happy to be the outlier you describe. Risk averse, proactive in preventative maintenance to have successfully avoided issues, problems and faults that lamentably, has so deleteriously plagued very many others.


    What’s not to like?



    But!


    Whilst on the subject of statistics, the sheer amount of equipment involved in the described annual plan, took six weeks to execute this year.


    Therefore, although I am overjoyed to be considered an outlier. In statistical terms, the actual volume of equipment that attracted this preventative maintenance, is statistically wholly relevant, to the degree that many would consider it, not to be the exception you appear to describe.



    Quote: “I have experienced many pot failures”



    I’m genuinely sorry to read that, perhaps some preventative maintenance might assist you?



    Quote: “they fail for many different reasons.”



    Quite correct!



    Quote: “Giving a knob a twist is not a guarantee that a pot will not fail.”



    It didn’t occur to me for a moment that it would ever guarantee such a thing, and I certainly didn’t state that anywhere.


    I’m sorry if my communication skills were so poor that I led you to imagine something that I never wrote.



    Quote: “exercising the wiper across the track can be helpful in certain circumstances



    With respect, I think you are on the right track here.


    Because, boiling it down that’s really the point I was making.


    Thanks for underlining the potential usefulness of such an easy precaution to undertake.


    I’m one of those that would rather build a barrier at the top of a cliff than a hospital at the bottom of it. Its easy to do, so why not do it? For as you state, it can be helpful.



    Quote: “it is not a panacea



    As far as I am aware, no one ever suggested that it was.


    I certainly didn’t use the word, and as far as I am aware, and with due respect, you are the only person to have actually used it.



    Quote: “I've had many high use pots fail and high use is in fact a failure mode for many pots.



    For sure, along with a whole slew of potential causes that could arise.



    Again, with respect, my point was really to offer an alternative viewpoint to that which is commonly held and which you helpfully mention.


    Simply that with insufficient or irregular use, certain electronic components can develop unwanted issues, and potentiometers along with dried out capacitors, absolutely fall into this category.



    As a footnote.


    Having met and knowing Mattias Carstens personally, one of the two founders and the chairman of RME. I have found him to be both very likeable and completely transparent about causes of equipment failure.


    With respect, however many amplifiers one might have built or repaired. Statistically the hundreds of thousands of professional products RME have sold over the years, places him in an entirely different league in regard to and with the benefit of evidential statistical data, anticipating the potential causes of component failure.


    You may have noticed a similar level of knowledgeable experience emanating from the excellent Kemper Moderators. Where their personal conversance and acquaintance with products and components permit them the gift, of anticipating and predicting the underlying cause of a problem.


    When someone in such a position that they can statistically predict the cause of component failure with that overwhelming level of product sales. And give as a manufacturer, clear advice as how best to avoid unwanted issues with their products. As in the case of advising that rotary controls fail more often because of too little use, rather than over use, I personally am bound to take their helpful guidance on board and actively benefit from it.


    I simply shared here what I had learnt from Mattias in the hope that others here, all of which have products that feature rotary controls.


    Might be genuinely helped, heaven blessed with equipment that continues to perform with excellence.


    Just as they were originally designed and fabricated to.


    That’s the simple level of my logic.

  • As I result I have yet to have ever needed to change a faulty potentiometer or had a problem with a rotary control.


    That’s over 57 years.

    I appreciate your previous post.


    Your statement "as a result" makes the claim that your preventative maintenance is the reason that you never had a faulty pot or rotary control. Period. Again, correlation is not causation. The explicit meaning, whether you meant it or not, is that periodically twisting pots or rotary controls prevents failures/problems. I've designed rotary control circuits and if you have ever used the scroll wheel on a Logitech mouse, then it is likely you have experienced my design. Twisting that scroll wheel(rotary encoder) has zero preventative value. Just one example of many. There are other types of encoders for which a twist will provide nothing preventative. My intent is not to quibble, but sending a general message to users that occasionally twisting a knob will result in never needing to change a faulty potentiometer or experiencing a problem with a rotary control is just not accurate.


    Edit: not that it means anything substantial, but the mouse scroll wheel rotary encoder has been a viable product for than 25 years and has sold well over 2 billion units. The b is not a typo. ;)


    Quote: “I have experienced many pot failures”

    I’m genuinely sorry to read that, perhaps some preventative maintenance might assist you?


    I like sarcasm(assuming you meant it that way) probably more than most. :) Either way, your response has no basis in my reality since the majority of failures that I see come from equipment that someone else owns. It shows up in a failed state that I get paid to resolve.

    Edited once, last by lbieber ().

  • Quote: “Your statement "as a result" makes the claim that your preventative maintenance is the reason that you never had a faulty pot or rotary control. Period.”



    Incorrect!


    I viewed the above, neither as a “statement” per say, nor as a “claim” as such. Nothing so grand at all!


    It’s simply that we as human beings have a natural propensity to think, speak and act in terms of cause and effect. This is pretty basic psychology I would have thought.


    So, you should reflect more deeply upon the preceding sentence as they form a naturally flowing stream of consciousness: “I consider the trouble it takes to do this, to be standard operating procedure and regular preventative maintenance, with an annual plan.”




    If you want to argue that standard operating procedures, and regular preventative maintenance, planned annually will not assist in avoiding component failure.


    Then there exists an overwhelming multitude of electrical designers and engineers, car designers, engineers and mechanics as well as aircraft pilots and maintenance crew who would actively take an opposite view.



    If you prefer to fly in a plane whose maintenance has been grossly neglected, then I defer to your personal choice, wishing you every good luck with that.


    However, I think prevention is better than cure, and after 57 years with a considerable amount of equipment, this approach appears to have served me very well indeed.


    Therefore, I commend it to you, it the hope that it will genuinely be of benefit. This forum is about trying to help one an another and really quite simply, that's all I want to do




    Years ago, my group was helped by the late Rupert Neve the inventor of the modern recording console, who put all his top bods at our disposal.


    And I live quite close to the factory where the Solid State Logic company design and manufacture the recording industries, state of the art professional recording consoles.


    To them, to argue that precautionary regular, planned, annual maintenance of professional electrical recording, audio and musical equipment was unnecessary; would I fear and I state it with all due respect, make any one who took that view, a complete laughing stock, hereabouts.



    Quote: “I've designed rotary control circuits and if you have ever used the scroll wheel on a Logitech mouse”



    Forgive me for pointing this out, but an electronic circuit is different to a electronic component.


    Just as a cheap computer mouse and its internal components differs in many respects, not the least being cost as well as qualitatively, to the rotary controls used in high end professional audio equipment.


    By way of analogy, as you are acquainted with computer equipment you surely must realise that not all hard drives are equal. The MTBF or “mean time before failure” varies greatly between models and makes, and between consumer models and models intended for professional industry application.


    All this is entirely self-evident or should be at least to any reasonable person.



    Quote: “sending a general message to users that occasionally twisting a knob will result in never needing to change a faulty potentiometer or experiencing a problem with a rotary control is just not accurate.”



    In that case, why have you written it?


    As I have not anywhere at all, written any such thing.


    Nowhere have I stated that: “occasionally twisting a knob will result in never needing to change a faulty potentiometer or experiencing a problem with a rotary control”.


    If I have, then let’s examine the evidence. For if you can provide positive proof that I have written such words, then with respect, you will be the greatest magician since Houdini.


    Again, with respect, you appear to have willingly conflated two entirely separate issues, which to a certain point I can understand. But the imaginatively novel attributions you claim that I have made, extend and augment quite simple points, into conclusions totally beyond anything, genuinely intended.


    Perhaps my communications skills are found wanting.


    Or English is not actually your native language.


    Or you have an over active imagination.



    Quote: “I like sarcasm(assuming you meant it that way) probably more than most.”



    Personally.


    I profoundly deprecate sarcasm.


    Being taught from any early age, it is the lowest form of wit.


    Irony is a much more effective humorous device I have found in my public debating at the Oxford Union and elsewhere.


    Speakers | The Oxford Union (oxford-union.org)



    Quote: “Either way, your response has no basis in my reality”



    I see that and clearly observe your singular outlook.


    You repair computer mice and so your point of view is based upon your experience.


    Last night my wife told me my son had rung her to say that he found a mouse running in their hallway.


    Pebbles their cat, had brought them the present of a live mouse (again) as a reward for all the loving care and attention they lavish upon her.


    I do appreciate that the issues one can experience with mice can be difficult to deal with and certainly would cause one to take a very particularly focussed view of the problems they present.


    Perhaps the question is, does your reality, directly and genuinely correlate to components utilised in high end and professional audio equipment designed for decades of use as against a disposable computer peripheral, consumers expect to replace?


    I think not!



    Quote: “since the majority of failures that I see come from equipment that someone else owns. It shows up in a failed state that I get paid to resolve.



    Thank you so much for sharing so freely.


    It is therefore entirely logical to assume that you have a vested interest in the failure of equipment that you design and repair.


    When consumers need to replace the item, and the sooner they do, you then have another opportunity to create an extra additional sale.


    From your statement you appear to make it crystal clear that as these problems arise for consumers, you are actually paid to resolve their equipment failures.



    With all due respect possible.


    Given that a renowned German manufacturer recommends the points I have shared as assisting in avoiding potential unwanted issues and their equipment strongly features rotary controls.


    And given that I have fifty-seven years of experience following a program of proactive preventative maintenance, with an exceptionally large amount of equipment and instruments, but have yet to experience a failure.


    You could appear to have a clear financial interest in doing everything possible to dissuade people from following such routine preventative maintenance programs. As if they did actively engage in such activity, you would eventually see your workload and income diminish.


    Where computers are concerned, I build my own and service and repair them myself. Though they rarely require it ever because of extremely careful component selection. Avoiding all the cheap cost cutting components typical manufacturers utilise. Hence “mean time before failure”.


    I hoover out dust from the computer insides, clean the fans and use a brush to clean out the heat sinks and processor coolers etc. All these measures are simple to do, and part of a routine that keeps everything running reliably as they don’t ever get over heated, because of any lack of routine maintenance.



    I see the concept and advantages of routine maintenance on whatever device it can be performed as totally self-evident.


    And argument against it, as argument, for arguments sake alone though I am sure you mean well and are simply sharing your point of view .


    One thing is crystal clear, performed with care, none of these routines can ever do any harm, and as far I and others I respect have determined, they appear to do a great deal of good.

  • Wow!!!


    We were simply discussing pots and rotary encoders, yet you have drifted far off topic. You even suggest that I might have a financial interest in discouraging preventitive maintenance. That fits well with my original post regarding your faulty logic. I would not fault you for inconsistency on this subject. Preventive maintenance is useful and I believe it is a good idea when it is acutally preventative. Labelling it preventative when it is not is misinformation.


    To anyone that has read this far. Please don't think that that twisting the knob on a pot is preventitive maintenance. It is not. In the case of a dirty pot, deoxit or cleaning spray can sometimes help clear a scratchy pot. Turning the pot after spraying is a good technique to help clean the contact points inside the pot. Turning the pot on a well funtioning unit as preventive maintenance is a silly notion.


    A rotary encoder is not a potentiometer. There are many different types and for some of these it is likely that infiltrating one with Deoxit or cleaning spray will damage or compromise it.


    Please take the time to understand the design of the particular unit and follow the cleaning instructions recommended by the manufacturer. Some manufacturers clearly state that there is no suitable solvent for cleaning their units. One such example:


    What solvents can be used to clean in the vicinity of the encoder modules?

    US Digital has found that almost all solvents (besides water) will attack some of the encoder module parts. This includes alcohol and freon-based cleaners. US Digital has not qualified any solvent to be compatible with the encoder modules.

  • Quote: “You even suggest that I might have a financial interest in discouraging preventitive maintenance”



    I was simply pointing out what you had actually written.


    Having read some of it, one can comprehend and appreciate how that might be embarrassing for you.


    As follows..



    Quote: “the majority of failures that I see come from equipment that someone else owns. It shows up in a failed state that I get paid to resolve.



    Thus, I was highlighting the truth that if you are employed to deal with equipment failures, routine preventative maintenance would undermine the financial benefit you accrue from those failures for which according to your words, you get paid to deal with.



    There’s nothing faulty about that logic whatever!


    But again, I do appreciate how that might be deeply and profoundly embarrassing for you.




    With respect, earlier you appeared keen to judge me by my own words.


    But subsequently rail against the fact as I pay you the respect of similarly judging you by your own words.


    The English language more than adequately affords a description of people whose attitude is: “Do as I say but do not do as I do.”


    Have you ever considered becoming a politician? The remuneration is good and you appear to be adequately equipped with the necessary gifts.



    Quote: “Preventive maintenance is useful and I believe it is a good idea when it is acutally preventative.



    I think it’s entirely self-evident that anything that has been found to be useful in preventing unwanted issues and problems is a good thing to know about and try.


    Especially if it can’t do any harm but might do some good.


    The point of forums is trying to help each other.


    And its why I have been writing all along.




    Quote: “Labelling it preventative when it is not is misinformation.”




    With respect, it appears that here, your logic can be deemed to be faulty.


    To be fair minded, what we can truthfully say is that you do not believe certain practises are helpful in any way at all. You have made your view clear.


    Contrariwise, we can also truthfully say that the founder and Chairman of RME, along with myself and the multitude of others who have followed his advice, have indeed found it to be extremely helpful and have subsequently avoided unwanted issues successfully.


    That internal company statistical data exists which substantiates that and is the basis for the given advice in regard to rotary controllers in high level audio devices, as well as, and in addition to, existent empirical evidence and the experience of practitioners of such routine maintenance.


    Hence there is a choice that presents itself.



    I trust we both agree that problems with both components are existent.


    Thus, one can refuse to believe the latter and not bother to engage in the simplest possible routines, thereby experiencing component problems and failures.


    The evidence for such issues abounds in past forums of equipment that utilises these high-end rotary controls and indeed typical instrument and audio potentiometers alike.



    Or.



    One can engage in extremely easily implemented routines and subsequently enjoy fewer, if any at all (as in my case) unwanted issues and problems.


    These routines do no harm whatever and are the simplest possible disciplines to invoke whenever its convenient to do so. What could be possibly be easier?


    I mentioned that more knowledgeable people than myself and I am sure, either of us, have given the excellent advice in regard to rotary controllers. So far so good in my view.


    However, although cleaning pots with Deoxit and turning them is a well proven routine practice in electric engineering situations. It is also true to write that many, just like myself, have found that simply turning a slightly scratchy potentiometer a few times, can very often clear the slight scratchiness that can occasionally appear.


    So common is this experience to the life of electronic guitarists and bassists etc. et al. That it appears alarmingly rudimentary to have to write it for you. That you appear to be unaware of this phenomenon, that almost everyone who has ever owned an electric guitar or bass, will have at some time encountered and easily cleared, simply by turning the knob a few times.



    Therefore, to rail against such widespread, proven routines that many players have instinctively utilised, without really thinking about it at all too much, appears argumentative to say the least.


    I prefer to consider that your particular limited experience with specific computer peripherals has given you a different outlook and that you are being honest to that singular view.


    And I trust in the innate wisdom and experience of electronic guitar and bass players everywhere to decide for themselves.


    Which course of action if any, is best to employ.



    Quote: “Turning the pot after spraying is a good technique to help clean the contact points inside the pot.



    Agreed!


    It is a well tried and tested, proven, maintenance routine.


    I believe in professional recording studio protocol's, standard operating procedures and regular routine maintenance.




    Quote: “Turning the pot on a well funtioning unit as preventive maintenance is a silly notion”.




    As is described above, that runs contrary to my and most other electronic instrument players experience. That is the only silly notion hereabouts.


    As many a suddenly slightly scratchy potentiometer has been cleared by the simple turning of a knob a few times. Albeit sometimes as just affording a temporary solution. It can work and often does work and hardy a player exists who has not used this device at some point in their playing experience.


    Sometimes it works sometimes it doesn’t, then cue the trusty Deoxit and try turning the potentiometer again a few times (as you clearly agree). But turning the knob is the primary, elementary act to try. That is pure common sense.



    Quote: “A rotary encoder is not a potentiometer.”



    This is written as though it were a statement of revelation.


    Who to? With respect, it would appear only to yourself, and to affirm the fact.


    As I do not believe anyone is unclear about that, apart from yourself who at times, have appeared to conflate the two together.


    (Places hands over face and shakes head from side to side). Where is a palm emoji when you want one?



    Quote: “There are many different types and for some of these it is likely that infiltrating one with Deoxit or cleaning spray will damage or compromise it.



    Thank you so very much for writing this.


    So you agree with me that a rotary controller in computer mice and rotary controllers on professional high end electronic audio equipment are quite different animals altogether.


    Although the mouse is one I am unsure which animal would adequately describe these monster encoders utilised on professional audio equipment with all the varying functions they afford?




    Quote: “for some of these it is likely that infiltrating one with Deoxit or cleaning spray will damage or compromise it.




    With respect, no one anywhere in this thread has ever advised the application of Deoxit or any other solvent on rotary controllers.


    I would be ridiculous to do so and again, with respect, the only person to have actually brought up the possibility of using solvents on rotary controllers is indeed yourself.



    However, I can well understand why you would do so.


    Having run out of any substantive arguments whatever to support the narrow views you hold. Based upon your knowledge of devices that do not directly correlate to the actual subject this thread is engaged in discussing.


    By initially engaging in Ad Hominin attacks (faulty logic indeed), your argument was clearly doomed to fail from the start. It is thus unsurprising that as your weak points of debate sink without trace into oblivion, a link to solvent use and rotary controllers might provide a diversion for those, who otherwise, will see your flailing hand above the surface, desperately grasping this straw of solvent use.


    I wish you a most happy day.

  • Quote: “I noticed 10 edits. Size matters.”



    I totally concur.


    Typically, I write in a word processor and transfer into the forum.


    As I can utilise the font and size and I am most comfortable with whilst writing.


    However, I edited the post and changed a number of words during the posting process.


    All the words and sentences added at that time turned out to be in a different font and a different size once the post was made.


    As you rightly state, size matters, so reading through the post afterward alarmingly found 10 different instances where consistency of font and size didn’t exist.


    But I gradually corrected them as time allowed with the other things I was attending to to ensure a more cohesive and readable presentation.


    It could be frustrating to me how at times, word processors change things like fonts and sizes, and change the words I wrote into something I didn’t.


    Happily, I am not the type to allow myself to be frustrated by such picayune issues, and I trust this helpful explanation satisfies any curiosity regarding the matter.


    Thank you for pointing it out and providing me this opportunity.


    And wish you every happiness for the forthcoming weekend! :)

  • FWIW, I have been repairing amplifiers (Tube and SS) over the past 30 years, and find that most pots, not encoders are usually cleared w/ a small spray of lubricant, such as CRC2-26. Occasionally the pots on a few of my amp repairs require a shot of CRC QD Contact Cleaner or Deoxit as well.


    Both of the CRC products work just as well as Deoxit and are plastic safe but at a lower cost. Usually I can buy the CRC products locally at Home Depot, I don't know if they are available elsewhere. Rarely does a pot require a 2nd shot and the usual wiping from Full CW to CCW unless it has been in storage or unused over a long period of time.