KVR Audio

ffaustin · Post by **ffaustin** » Wed Feb 09, 2011 9:18 am

I spoke to KRK this morning and they suggested buying a whole new amp which is insane for $100+ considering the set cost me around $300ish if I remember correct. I am way out of warranty so no harm in taking a peek.

To my surprise I think I found the issue?! At least KRK's failure is blaring-ly visible like the loud buzz coming from my speaker.

Gotta see if the local electronic store has the replacement capacitor.
Same issue both speakers. I don't think this is a coincidence.

I am super disappointed with their customer support!

dodokvr · Post by **dodokvr** » Wed Feb 09, 2011 9:30 am

If you're in the UK then buy from someone like DV24/7 who give a 4 year warranty and have an excellent, efficient returns policy. Absolutely essential on big items like studio monitors because they have a habit of not lasting the course.

ffaustin · Post by **ffaustin** » Wed Feb 09, 2011 9:44 am

Im in the US. They had a 1 year warranty on these (KRK Rokit 5 Gen1). Companies that produce good products have no issue providing a 5 year warranty because they know their chances of product failure are minimal and they will not hurt by providing this service. And on the other side of the spectrum …

C00kie · Post by **C00kie** » Wed Feb 09, 2011 9:51 am

The real question here is: why did that cap blow? Just bad quality of the part, or was it pushed over it's limits due to bad electronic design? And did it take down other components in the process as well? You don't know that, yet... Also one of the reasons they advise to replace the whole amp pcb.

In this case the blown cap is quite visible. But what if there's no sore thumb sticking out? Do you realise how much time it takes to find it in that case? That's why repair centers just replace whole PCBs and not go looking for the one faulty part. For them that's efficiency. Labour is more expensive than parts.

ffaustin · Post by **ffaustin** » Wed Feb 09, 2011 10:21 am

I got nothing to lose!

ffaustin · Post by **ffaustin** » Wed Feb 09, 2011 10:22 am

The KRK Tech Rep on the phone admitted to low end product manufactured cheaply.
It is the same capacitor on both speakers which gives me faith.

ffaustin · Post by **ffaustin** » Thu Feb 10, 2011 8:49 am

Just replaced the capacitors in both speakers. Works perfect! NO BUZZ!
$250 for 2 new amps or $2.80 for 2 new capacitors?

C00kie · Post by **C00kie** » Thu Feb 10, 2011 9:29 am

ffaustin · Post by **ffaustin** » Thu Feb 10, 2011 9:58 am

Thanks!
I thought this was interesting too:

http://en.wikipedia.org/wiki/Capacitor_plague

I hope this is motivation for people to take a chance and take a look inside!

adamrobt · Post by **adamrobt** » Sat Mar 19, 2011 7:15 pm

I am so glad I found this thread while searching the web about my Rokit 8's humming problem. Thanks to SteveBurley and his input on the matter, my humming problem is now gone.
As soon as I read his response I pulled the power cables and snapped the ground plugs off and presto- the hum was gone. The problem seemed a hundred times worse this morning after doing some rearranging of my equipment and really pissed me off. I pulled the amp out of one of my cabinets a couple weeks ago thinking the RCA connection might have a bad ground or something because it's the only input I've ever used on these speakers. I had no idea how crazy the guts of these speakers were going to be. I checked everything I could check with a DMM and looked over all the PCB's and could not see anything obvious. I was lucky to get the thing back together in working condition. After doing this I bought some 1/4" to RCA adapters and tried hooking it up that way and still got the same ol hum. This is just the last week or so of a problem I've faced since I moved into this house. I never put 2 and 2 together but now it all makes a lot of sense.
This morning when the noise was the worst, it was probably from the speakers being plugged into 2 different power strips plugged into two different outlets.
I'm so glad to be rid of my humming problem and that I didn't have to do any internal repairs. If you do have to get inside the speaker for something, only remove the screws on the perimeter of the amp. In addition to those screws I removed 3 that held part of the crossover to the plate and it was a bitch trying to get back together.
Thanks for all the help here!!

Jim Y · Post by **Jim Y** » Sat Mar 19, 2011 7:48 pm

There have been "bad caps" around for some years due to a Chinese manufacturer using a faulty electrolyte formula.
http://en.wikipedia.org/wiki/Capacitor_plague

Jim

Ninety9 · Post by **Ninety9** » Sat May 07, 2011 7:53 am

I have a humming issue with my RP5 G2s. I think it's more down to the cable than anything. If I just plug them and turn them on I can only hear a slight hum when putting my ears right by the woofers but as soon as I plug them in to anything (RCA) I can hear a horrible humming noise. Totally distracting when in silence.

Would buying better cables help ? It was only a cheap cable from maplins.

C00kie · Post by **C00kie** » Mon May 09, 2011 7:05 am

No, it's not the cable itself. You probably have a ground loop.
If you're using a notebook PC, try running it on batteries.

Ninety9 · Post by **Ninety9** » Tue May 10, 2011 7:31 pm

You're right, it's definitely a ground loop issue. When plugged into something the hum becomes noticeable. I tried plugging it into the headphone jack of my Macbook Pro but the hum still persists. I was plugging it into my TV before as I use a Sony Bravia as my main screen. Both the TV and the Laptop produce the same level of hum.

Tried unplugging the laptop and running on battery but still no luck.

What next

EDIT : Some places sell Ground Loop Isolators which sit in between the pieces of equipment you're connecting together. Are they effective ?

RunBeerRun · Post by **RunBeerRun** » Tue May 10, 2011 7:38 pm

Yes they are effective. Also necessary when using a computer with any decent monitor, as in not from best buy, made only for computers.

I use the Behringer hum destroyer.

Krk RP8 hum