Jump to content

Noise. Static/fuzz noise from all speakers.


I3ulldog

Recommended Posts

  • 1 month later...

I have had the v.2 400 series speakers for nearly 9 years now. I remember having to get the controller replaced because it was buzzing and the volume adjustment created static (this was around 2002). Since then I have been blasting and blasting and blasting ..... continously since then. Last year both the woofer speakers blew from overuse and dry-rot, but the rest of the satellites and amp were fine. I have been running them with a JBL 10" sub in parallel since then.

So to the relavent subject, I just acquired a set of nearly new Promedia 5.1 (NOT Ultra) from work (free.99!!). Finally an upgrade after a decade. I hooked them up and got the infamous humm/buzz/hiss out of all speakers. From prior experience with the v.2 400's, I am guessing it's the controller, this is why:

* Twisting the volume knob to 80 gets rid of the hum for me. This fixes the problem (kindof), I just have to turn my itunes gain to -12db and volume to 1/2 in itunes and 1/2 gobal to be able to listen at a normal volume (until I get a deafening email notification.

* when playing with the volume knob, the hum will intermittently change and dim, and the volume drops/jumps quickly sometimes.

Now for questions?

The strange thing, when I turn off the the speakers or unplug the controller, them make a electronic "zipping-up" sound? This is definitely from the amp, since it happens right after I unplug the controller. Is this normal on the 5.1's, I have never heard it on the v.2 400's?

I Found a 5.1 ULTRA controller on ebay, can this work with the 5.1 no-so-ultra?

Thanks

Link to comment
Share on other sites

  • 6 months later...

I just got a set of ProMedia GMX D-5.1 speakers from my uncle. After hooking them up I got a hiss from all five speakers. I though maybe it was because I was using an analog conenction, so I switched to COAX but I still have the noise, but now it goes away if the speakers idle for more than 3 seconds. I opened up the subwoofer and the controller. The subwoofer looks fine, no broken parts and so does the controller.

In the controller I noticed 5 opamps, 5532, and the DAC, CS4228A. Could something like that be bad? I don't think it is the opamps as all the speakers have the same amount of static. Also when the controller is off the noise is gone so I am almost positive it has to do with it.

Any help would be great.

Thanks,

Justin

Link to comment
Share on other sites

  • 13 years later...
On 1/27/2023 at 4:21 PM, OO1 said:

this set is very old ,  wild guess here ,  try using DeoxIT   


It is old and I've had to replace a both BASH chips and some resistors in the past, but they worked flawlessly until recently!

 

I opened it up and took a look around, nothing appeared burnt or out of place. But I do hear a very similar high pitched static noise coming from the daughterboard that holds the BASH chips. I resoldered the BASH chip solder joints just in case, didn't seem to do anything. I'm assuming the culprit is somewhere in daughterboard, but I have no idea how to go about figuring out what needs to be replaced since everything is very tight and hard to get to.

 

I know this seems like a "well duh dude" moment, but I do have an electric space heater in the same room I use occasionally and sometimes when I turn the heater on or off, the static over the speaker either turns on, off, or gets worse. This might point to an interference issue, but if the static can happen even if the heater is unplugged or off. I've had the heater for several years and it didn't trigger the static until very recently. With that in mind, I'm just assuming a component (cap or resistor) that is failing and can't take the power fluctuations the heater is causing.

 

As for the DeoxIT, isn't this a solution for the volume knob? I don't seem to have static if I increase / decrease the volume. Or is there another way to use it?

Link to comment
Share on other sites

4 hours ago, K.C. Cool said:

 

 

 

As for the DeoxIT, isn't this a solution for the volume knob? 

correct  ,I was under the impression that you were saying that  the volume potentiometer was  a source of static , 

Link to comment
Share on other sites

Hey again all, I pulled apart the amp again and tried taking a closer look at the AC/DC converter and noticed some components that look a bit toasty.

 

https://imgur.com/a/BUo3bmG

 

I tried resoldering everything that looked like it might have come desoldered, but I don't really see much of an improvement in static. Does anyone know which bits of circuitry I should replace here? And if so, is there an easy way to identify what I need to purchase?

Link to comment
Share on other sites

  • 2 weeks later...

Hey all, I just wanted to follow up. A big thanks goes to @stpeteshepherd for pinpointing my issue with the capacitors on the AC-CD Converter daughter board, as I did fix my intermittent hissing issue! More details below...

 

With this kit being close to the cost of a mail-in repair ($130-$150 depending if you go with the kit or repair), you kind of need to weigh your own cost / benefit / abilities with a system this old. I reached out to @stpeteshepherd and decided to buy his 5.1 Ultra repair kit with a fan. My reasoning for going this route is: I have a beginner's ability to desolder / solder and have repaired this system before thanks to forum members like yourself sharing information. @stpeteshepherd has reengineered 3 components (BASH chips and AC-CD Converter Daughter board) to be cooler and longer lasting which is a godsend for a system this old with faulty parts. I also wanted a kit that had everything I needed to fix my current issue and future issues with this system without guessing, along with instructions. With that in mind, If I knew exactly what to replace, I could have bought some of the components that fixed my specific issue for less than $20, but I will inevitably have to replace/fix something in the future as these systems are prone to breaking due to heat issues.

 

Something keep in mind that as time goes on: less and less people have these systems and Klipsch Promedia electrical enthusiast may not be selling / repairing these forever, so I figured buying now is an investment in the future of these 501 Ultras 😃.

At first I sought out to do a full repair and replace everything in the kit, so I tackled the two 16v 100 uF and two 35v 100 uF capacitors at the upper right corner of the panel near the pair of small black heat sinks in the picture attached. Years ago I replaced the 35v 100 uF capacitors due to a bass hum, but I decided to replaced these with the new ones in the kit since they were and upgrade / a higher temp rating. Doing so, I accidentally pulled out a copper trace from the board because I didn't fully desolder. Stpteshepherd even warned me of this in the instructions 🤦🏼‍♂️. Re-attaching a trace is currently outside of my electrical wheelhouse, so I thought I ruined my system.  I attempted to solder the capacitor back anyways on the top and bottom of the board and it seems to be working fine, but I'm not sure if this is a permanent fix or not.

Due to this FUBAR, I decided to focus on what I believed my main problem was: The AC-DC converter board with the three 22uf 50v capacitors, 2N5551 transistor, and Zener diode on the AC-DC converter board (picture attached). I wanted to focus on this area first as this was the only area where the bottom of the board was charred. After replacing these 5 components and starting the system up again, it stopped buzzing and hissing. Once again, silence! Huzza!

Pro tips: When removing the AC-DC board, use needle nosed pliers to grab the plastic mounts under the board and unscrew the screws holding those in place on the outside of the panel. I tried to press the plastic prongs in, but the plastic is so old the prongs broke off 😑. All in all, if you are having this problem and stumble upon this forum post, doing this repair is pretty easy and even a beginner with a solder sucker and a soldering iron can pull this off.

@stpeteshepherd also gave instructions in the kit to replace many more commonly failed components and an internal fan kit to keep everything cool. Since my previous repairs are currently holding up (for now...), I didn't attempt to replace anything else in fear of causing more damage than good. I'm sure something will fail down the road, but I have the parts and instructions to tackle them when they come at me 😃.

It's crazy to think about keeping these nearly 20 year old speakers going, but they still sound great and are fairly simple to repair. I hope this helps someone in the future!

PXL_20230212_212729224.jpg

Yh1yNQC.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...