i-Fi volume control malfunction

[dbert]

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.

[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.

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

[dbert]

Hi Todd

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

[Todd Davis]

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

[dbert]

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

[dbert]

The microcontroller on the dock that is used to send the data to the LM1973 in the sub appears to be a 32 pin MC68HC908JL8CFA.

[link=http://www.freescale.com/files/microcontrollers/doc/data_sheet/MC68HC908JL8.pdf] M68HC08 Datasheet[/link]

[Todd Davis]

dbert -- thanks for the kind words and additional information on the MC86Hcrlk38%#82148$8* IC. Well, that's a surprise of sorts. I just took my dock apart and yep, that's a scary thing to see. That's basically a PLA, similar to a custom microprocessor circuit. Very complex internally -- which when compared to drivers and other high current devices, tends to rank among the more likely components to fail. I had my unit unplugged for a day and when I powered it back up it worked somewhat reliably. That steers me more towards this type of circuit as a likely failure tho that's not to rule anything out completely elsewhere. Temperatures influencing a breakdown in a component.

I guess for the moment, I have to go back to my request a few days ago -- where's a schematic and oscilloscope? I'd think that if I can get my hands on a print I can sort this out.

Unless one of the fine folks at Klipsch might want to weigh-in on this... Like I said the other day, most people would prefer to fork out the $57 to replace the dock if they know within a reasonable degree of certainty the replacement docks have resolved the problem. Or, just help the tinkerers of the world who will figure this out anyway, and just do the right thing by letting us know what the bottom line is about the docks.

Keep me posted -- and thanks again for everything.

Todd

[emice]

Just had the same issue crop up. I just read the spec sheet for the LM1973, the volume controller inside the sub, and it defaults to mute on power up. So if volume change messages aren't being received for whatever reason (failed microncontroller in dock, bad cable, noise, etc..), you won't get sound. The controller takes a serial stream of 8 bits to select the channel and 8 bits to set the attenuation level. More than half of the bit combinations for attenuation level result in a muting action. Only the last 3 bits of the 8 used to set the channel are used, the others are always 0's, since the chip only supports 3 channels. These channels are used for left, right, and sub. Normally the dock sets the left and right channels to the same levels at the same time, but noise could cause their levels to get set independently.

If the dock connector's clock and data lines go straight to the LM1973 chip somebody could probably make a circuit to control volume by sending the right 16 bit values. It could be simple and just set the volume on all 3 channels to max, or support ramping up. One problem might be that the custom microcontroller code in the original dock might be curving the volume up differently for the sub vs. the satellites, throwing off the original balance. Still better than nothing. If replacement docks continue to fail someone might find it worth their while to make and sell such a volume level setting "adapter" to skip the dock all together.

Lastly, I am reading that the docks were no longer for sale for a while and then recently brought back, does that mean these docks may have bug fixes that prevent future failures? I'd gladly pay for a reliable dock. Like a lot of people have said already, no one has made a better 2.1 set since these came out. Klipsch - why don't you update this set and re-release it, either excluding the dock or fixing the reliability issues, while keeping the Class-D amplification and the RSX-3's. Isn't it nice to be the class leader?

These speakers bring you a lot of cred, exposing the brand to a level/segment of customer that is less likely to be familiar with the brand. I have recommended the ifi set to several people and many of their friends that were surprised by the sound of these "computer speakers" now know and remember Klipsch name. These are people that find buying amplifiers and speakers by component too cumbersome to delve into, but can still appreciate the extra quality the the ifi brings over the existing promedias and high end logitechs. It makes the cost benefit of the brand clear, at a less risky price point, in a way the promedias can't. The dock is useful in getting these customers so I'd suggest including it, but working out the kinks first.

I'm keeping my fingers crossed that someone comes up with a long term fix for this. Also, if anyone has experienced reliability issues w/ the docks just recently being sold, please speak up.

[ronwes]

Hi there,

Ron here from Amsterdam, the Netherlands.

I'm following this blog with great interest as my IFI also has the same problems. I am not a technician and I can only hope that a permanent solution for this malfunction can be found. I really do not understand Klipsch not doing anything as this potential will damage their brand name....

Reading the posts here, the malfunction in the dock (correct me if I'm wrong).. Would it be an idea to try other docks, e.g. promedia, is the connection cables are the same to see if this fixed this? or is this to simple?

Ron

[ronwes]

I have also sent an email to support asking for help, cc't Sarah Knight (press contact) and Fred klipsch (CEO)

Let's wait and see what comes out,

Regards,
Ron

[enderty]

my iFi had the same random channel & sound popping issue starting about 9 months ago (less than a year after it was purchased new from klipsch). I didn't need it at the time so I tossed them in the closet... well long story short I'd like to use them now as computer speakers so I figured I'd buy the new dock and see how long it lasted.

Weeeelllll the new dock didn't fix the problem. Turning the volume control still makes the sound skip from channel to channel unless you get lucky and land on some combination of sub volume and main volume that puts the sound through all channels. However even this isn't quite workable because it seems that the unit is stuck at 100% volume and has a constant hiss through the satellites even with no input connected.

Is it possible that this brand new dock is broken or is the issue more likely in the amp?

-Ty

[RichSad]

Ty,

The behavior you describe is EXACTLY what is happening to me. I haven't yet bothered to update the dock since it seems in a good percentage of cases that is not the problem. I bought my IFI when the product first launched and paid close to $500. It really irritates me that a $500 speaker system from a reputable manufacturer would break. I was quite happy with the audio quality when it all worked correctly, but I feel strongly that there is a serious flaw in the design based on this problem we all share.

I am based in Massachusetts these days and would love to hook up with someone qualified to fix this system for me for a reasonable fee. I don't feel I should be giving Klipsch anymore money unless they are willing to fix this for me. If they offer to fix it I would gladly pay for the shipping back and fourth.

Anyone from MA with the required skill set?

[tc3sean]

I am as well having this problem. Except, My rsx's are working fine and sound great, But It's my subwoofer that is acting up. It works on and off, but rarely. It will work if I turn the volume up atleast 1/2 way on the pod, it doesn't matter either 3.5mm jack or Ipod dock. Subwoofer setting doesn't make a difference of it turning on, the volume just has to be atleast 1/2 way and it will turn on and off inttermitently, It;s very annoying! Is it that IC chip going out?! [:@][:S]

[emice]

Just received a replacement dock. Didn't work. I guess the problem is in the sub.

Something else I'd like to add is that the fuse has gone out numerous times in the past, but it didn't happen much once I stopped using the switch on the back to turn it on. When I first got the speakers the fuse blew out within a couple days, and I almost sent the unit back for a replacement. After emailing with Amy at customer support and asking if I could try swapping the fuse myself, I ended up just doing that. After the limited warranty for the refurb ran out, I had to do it a few more times. Something was causing an in rush of current to blow the fuse when the unit turned on, perhaps this may have something to do with why my unit finally ceased to work.

[tulient]

I just want to mention that I also have the ifi volume problem. It started as a nuisance and I could fix it by moving the volume up and down. Up until a few months ago it took a few minutes to find a good calibration and I would just change the volume through the OS. I didnt have to change anything until it lost power. This was fine until this week when the speakers all of a sudden seemingly go into standby mode without me telling them to. In addition, messing with the volume control became a more challenging game, taking 10 to 30 minutes.

I finally got sick of it and ripped open the dock. I couldnt find anything that needed to be resoldered or any loose connections but apparently the motion of taking apart fixed something as I am now once again able to control the volume, at least up until half volume where I lose one speaker or the other.

I kinda want to get rid of my IFI now though and get something thats not discontinued and has shitty support. Cant really sell it easily now either, as who would want to buy the speakers with defective volume control.

[dbert]

Is there no simple data reader for this type serial bus?

Ok, I just realized how stupid that sounds. No databus reader is so simple you can pick one up at Wallmart.

It's just 16 ones and zeros in a row. Many never used (always zero) Can it be that hard to read/inject? Where are the electronic guru’s?

[tc3sean]

Im going to try to replace that microcontroller inside the sub when I get around to it. Im not having any trouble with the 2 channels operating on their own, but Im having my subwoofer cut out at lower volumes. Ive checked the wires once, and their fully seated.

Heres a place to buy it at http://parts.digikey.com/1/parts/467232-ic-audio-attenuatr-w-mute-20soic-lm1973m-nopb.html

Is there a trick to desolder multi surface mounted point's at once?

[duppa43]

I too am having this problem. I would love to salvage this system in some way. i.e. use it with a receiver without the dock, or find a way to fix this stupid dock. Has anyone figured out a solution?

[thenewguy]

I also have this problem. Is this a typical response by Klipsch regarding a malfunction? I would imagine the manufacturer would at least be able to isolate the problem and let us know whats causing the problem and how to fix it. I'll definitely not be buying any more Klipsch hardware with this issue still outstanding.

[duppa43]

So I guess no one has a solution to this problem. I guess we all have a $350 set of magnets to stick on our refrigerator.

Quite frankly, I have never been treated so poorly by a company. And to see some of the problems people have had with Klipsch on this forum, I think we should all boycott the company.

I have always liked Klipsch products and have supported them wholeheartedly. After this ordeal, I am making a personal commitment to bashing the Klipsch name to everyone I talk to!!!! And I work in speaker/electronic sales

CAN YOU HEAR ME NOW KLIPSCH! ?!?! HOPE YOUR MODERATORS ARE LISTENING!!!!