I decided the volume control knob is a rotary encoder similar to this.

http://www.mouser.com/Search/ProductDetail.aspx?qs=seHrhfPpLDyxH7JES5SCFA%3d%3d

I opened up my sub last night and found this on the board with the din connector.

Googleing LM1973, this appears to be a common volume control IC.

I am not smart enough to reverse engineer this whole volume control so how about throwing us a bone and at least provide the pinout on the DIN if nothing else. I just want a chance to have a working 2.1 system.

 

 I am having the same problem as others. I am very upset. I can't get output out of both left and right at the same time anymore. There are loud popping noises when sound turns on or off. I am not using an iPod, I am using this with my computer. Used to sound sweet.

 I bought these around 2003 or 4. They were $500. I expect them to still work. How do I fix this? Is their a repair shop in Massachusetts?

Sad to say you are probably out of luck. I sure wish I had some idea what the culprit was so I had some idea if there was any way possible to make them work just as computer speakers. I tried replacing the rotary encoder on one of my docks but it still did the same thing.

Mine failed again last week. I also do not use it for the Ipod but for my computer speakers. This dock was the 4th one in 3 years.

 Gents: thanks for the response. Klipsch support indicated it may be the dock, the amp or both and suggested I try the doc first. I'll give it a try for $60 or whatever. If I can save these speakers for that price I will remain happy. If not, I will become a dissatisfied customer.

dude, this problem is stupid. Klipsch acts like they still haven't realized this problem goes on, and pretend like they dont know whether it is the dock or the amp. can u reply when you find out whether replacing the dock works? cuz i don't want to replace the whole f*cki*g sound system. thanks

 I willl certainy reply Dani, but I should warn you a little trial and error I've gotten the system where it is working for the moment. So I don't plan to purchase the new dock until the next time the sound goes out in one of the speakers (or other serious problem). If I don't touch the wheel it seems to be stable for the moment. I suspect it may work like this for another week or two!

i got my ifi to work once in a while when it first stopped working right, but then after a while, it would never work. even if i waited for a month or so, the problem didn't go away. i tried adjusting the wheel slowly and all over the place, like in between notches, but no. what did you do anyways to get it to work again?? just adjust the wheel??

 Dani, yeah I just adjusted the wheel and pushed down on it a bit. I doubt it will keep working for long.

aww alright, im gonna see if i can get a klipsch engineer or worker or someone to look at this forum, i dont feel like paying $57 on a just a little dock piece when i bought the whole system for $200 and its not guarenteed to fix it. so yeah

I can assure you that Klipsch engineers have viewed this forum from the beginning. The continued silence is deafening.  Is it hardware in the dock, or in the amp? Is it hardware or software? Is it related to prolonged muteing?I got an email today informing me that the docks are available for purchase. Should I try one more? They say the definition of insanity is doing the same thing over and over again expecting different results.

If these were not awesome speakers I would have tossed them out and forgot all about them years ago. Because I check this thread once a week or so, I keep wondering if I have an obsession with finding the problem.  I know too little about electronics to pretend I can figure it out on my own. It’s not like I can experiment with some sort of serial data signal generator or even know what to do with it if I had access to one.

http://www.national.com/ds/LM/LM1973.pdf <- what the iFi uses if you know someone who understands all this.

I am wondering this. If I order yet another replacement dock, and never touch the mute switch, will it last? I’d like to open up the dock and disable the switch so I know no one in my family will even be able to, if it is the contributing factor.

hi there - new here, and yes, I have a iFi that is having the same problems with the iPod dock/volume. I think many have been asking the wrong questions here for some time. The issue is, what specifically is causing the problem and what can users do to rectify that problem. It's no benefit to speculate on whether or not Klipsh knows about it or has parts, or whether this part of that is the culprit, etc., in my opinion. A few things. On the volume controller chip specified above, I've worked (technical) in consumer electronics for many years and basically this is a three channel audio level controller that works by receiving serial data. I doubt this is the problem, and from what I've read, I doubt it's the volume switch (though I wouldn't rule that out at the moment). What I think is happening is there is some type of electrical noise that is getting introduced into the dock. Data is being sent from the volume switch and buttons on the doc, and either fed directly into the LM1973 controller (or into the main woofer unit, where it is returned as control data) to the LM1973 chip) to control the volume. If there is a weak ground along the cable, or weak/"noisy" connection in the serial data stream sent to the chip the resulting control/function could become erratic. (I've also noticed what sounds like dry capacitors in the main unit for some time as well, this causes a constant buzz in the audio and could also mean noise in the unit's power for the logic system. This could also create an erratic condition similar to a faulty or weak ground.) This is to say, "noise" in the cable connecting the dock to the main unit will disrupt the data in-between the two devices and lead to the problems many are experiencing. I'm willing to help, though I'm not working in the biz anymore, I've been there for years. If someone can get me a PDF of the schematic that would do wonders. I'll check back here periodically. (April 12, 2009). P.S. I'm new to blogs and all that fun stuff, so if there's a better place to provide input/assistance, please let me know. Best, Todd

Hi Todd

Todd Davis:

hi there - new here, and yes, I have a iFi that is having the same problems with the iPod dock/volume. I think many have been asking the wrong questions here for some time. The issue is, what specifically is causing the problem and what can users do to rectify that problem. It's no benefit to speculate on whether or not Klipsh knows about it or has parts, or whether this part of that is the culprit, etc., in my opinion.

At this point I couldn’t agree more.

A few things. On the volume controller chip specified above, I've worked (technical) in consumer electronics for many years and basically this is a three channel audio level controller that works by receiving serial data. I doubt this is the problem, and from what I've read, I doubt it's the volume switch (though I wouldn't rule that out at the moment).  What I think is happening is there is some type of electrical noise that is getting introduced into the dock. Data is being sent from the volume switch and buttons on the doc, and either fed directly into the LM1973 controller (or into the main woofer unit, where it is returned as control data) to the LM1973 chip) to control the volume. If there is a weak ground along the cable, or weak/"noisy" connection in the serial data stream sent to the chip the resulting control/function could become erratic.  (I've also noticed what sounds like dry capacitors in the main unit for some time as well, this causes a constant buzz in the audio and could also mean noise in the unit's power for the logic system. This could also create an erratic condition similar to a faulty or weak ground.) This is to say, "noise" in the cable connecting the dock to the main unit will disrupt the data in-between the two devices and lead to the problems many are experiencing.

I don’t know, but it seems it could be corrupt data to me. Look at the channel selection bits in byte zero, and the attenuation data in the second byte. With the volume jumping all over the place and from one channel to the other it looks like the wrong bits are changing when you rotate the digital encoder. If it were simply “noise” or a weak ground, wouldn’t it be erratic/intermittent regardless of selecting volume?

I'm willing to help, though I'm not working in the biz anymore, I've been there for years. If someone can get me a PDF of the schematic that would do wonders. I'll check back here periodically. (April 12, 2009). P.S. I'm new to blogs and all that fun stuff, so if there's a better place to provide input/assistance, please let me know. Best, Todd

I’d be the first to welcome help from somebody in-the-know. If the folks at Klipsch don’t mind, I think this would be a good place to discuss it.
Because I haven’t been able to even get a pinout of the dock to sub cable, I don’t hold out much hope for more system schematics. I still can’t believe someone went to the work they did on their own to come uip with these Klipsch schematics for the promedia stuff.
http://www.thompdale.com/bash_amplifier/bash_amp.htm

 

 

 

Hi dbert - Thanks for the comments and follow up. Well, a few to add, process of elimination and avoiding the grimbly. I received a response from Klipsch today re. volume issues. Their response to my request for service info. etc: "purchase a new dock" for $57. Provided they suggests takes care of the problem, then for the moment we can presume the problem is in the cable to the dock. (And reading your comments, I'd say, toss the IC into the suspect pool. Often in my service days, we'd see a bad batch of chips come down the pike that would mess a lot of things up. However, high power, high heat, high demand ICs fail 100:1 to simple, low-power ICs.) It still may be noise in the power, grounds or from the volume switch, or pot. (I'll look it up eventually). That's to say, because the circuit is essentially idle until input is sent to it, low/noisy power, and/or faulty grounds may only have an effect once the chip begins to function. This could be determined easily with a schematic and oscilloscope -- which I have neither in front of me at the moment. As a former service center owner, I would routinely contact companies, such as Klipsch, and order a schematic. These days with the Web, more of that's done online with PDF-types of diagrams. I haven't seen any out there as of yet. Perhaps if someone knows of a service center who has the diagram or would be willing to order one, they could let someone know. If anyone is reading this at Klipsch, no bad feelings, I hope. I'd figure for most, it is easier to spend $57 to buy a replacement than spending an afternoon taking apart a dock and trying the do-it-yourself routine. I think, however, 1.) if people felt confident the replacement dock wouldn't fail prematurely like the original ones did, they'd just order it and go on their merry way, and 2.) for those of us who would prefer to mess with our own stuff, we'll find the cause/solution eventually -- with or without your support -- and then we'll blab it to others. So, a little honesty and help could be in order here. But what do I know, I only handle corporate communications for a Fortune 10 consumer products company. TD

I am excited to have you show up here Todd.

 I ordered a replacement dock when they became available a year ago or so. It worked fine for about a month and then had the exact same failure. They have been unavailable again until just recently. Because I tried that once already I am not too anxious to try yet another without knowing this batch is somehow different from the others. But.. the replacement dock did work for a short while. That must mean something.

This volume controller IC in the amp doesn’t seem to be reported (googleing) as problematic in other applications.

 An interesting tid-bit… look down the forum topics a short ways for the discussion of using the jamo i300 dock with an iFi.

Another interesting thing reguarding the dock cable, it appears they use the same cable they use for the promedia 5.1. Andy says the signals are not the same, but the hardware is. http://forums.klipsch.com/forums/p/81032/809128.aspx#809128