GK 212MBE buzz help

lowrocker · #1 10-09-2011, 09:03 AM

I just purchased a GK MB500 and a GK 212MBE. I have owned it for a month now and last night when I shut the head off it made a very loud pop through the cab.

I never had any issues before that, it played and sounded great. I turned it back on to test it and there was a very noticeable buzz when playing. I turned down (then off) the boost and it was still present, but less especially when I picked hard on the strings. I use all good cables and it happens with both passive and active basses.

I play a little on the hard side and it never did that before. The head is only putting out 350 watts and the cab is rated at 600 watts. There is no way that should be pushing the cab. My gain never went past 12 o clock. My settings have never been an issue and just to make sure, I set everything flat and it still makes the noise.

I have contacted GC and will address the issue on Monday. Any suggestions, experiences or advice?

Thank you

BassmanPaul · #2 10-09-2011, 10:17 AM

You have to remember that cabinet wattage ratings are usually thermal or the level when the drivers start to melt. Drivers tend to run out of excursion at around 50% of their thermal power. After that the cabinet gets no louder and the drivers are being damaged.

lowrocker · #3 10-09-2011, 05:53 PM

Thank you Paul for the input.

garagebassman · #4 10-11-2011, 07:48 AM

I have been running the same rig for near a year now without any issues....was the MB500 bought new ?
I have never heard any noise during power up or down....was power removed from amp (or power strip, supply etc. ) before amp completed shutdown perhaps ?
can you try the head/cab with other head/cab to isolate source of noise ?
either that or trying it at GC should point you in the right direction......
should be warranteed through GC even if not bought new I would expect..

keep us posted on the result , hope it works out !

lowrocker · #5 10-11-2011, 08:57 AM

Quote:

Originally Posted by garagebassman

I have been running the same rig for near a year now without any issues....was the MB500 bought new ?
I have never heard any noise during power up or down....was power removed from amp (or power strip, supply etc. ) before amp completed shutdown perhaps ?
can you try the head/cab with other head/cab to isolate source of noise ?
either that or trying it at GC should point you in the right direction......
should be warranteed through GC even if not bought new I would expect..

keep us posted on the result , hope it works out !

Everything is brand new bought together. I tried another head and the buzz still was heard while playing hard. It was plugged into a wall socket and there is no shoddy wiring. I'm at a loss. How could the speakers get damaged by not completing shut down? Aside from some unseen surge or an issue in the head, I don't know what happened?

I am contacting GK today and dealing directly with them. One of their service centers is the next town over. I will keep you posted.

garagebassman · #6 10-12-2011, 08:20 AM

Is the noise more noticeable or more noticeable on certain notes/frequencies ? Or is it the same over different notes ?

I'd say dealing with GK direct is and excellent plan.....almost everyone has "not so good" stories of dealing with GC, even though they may try !

The pop during power down just sounds uncharacteristic...maybe it did some damage to the cab

Does the tweeter on/off make any difference ?

stflbn · #7 10-12-2011, 08:37 AM

Hasn't there been some comments about grill rattles with these cabs?

Might try removing the metal grill and see if your buzz goes away.

will33 · #8 10-12-2011, 10:20 AM

Quote:

Originally Posted by lowrocker

Everything is brand new bought together. I tried another head and the buzz still was heard while playing hard. It was plugged into a wall socket and there is no shoddy wiring. I'm at a loss. How could the speakers get damaged by not completing shut down? Aside from some unseen surge or an issue in the head, I don't know what happened?

I am contacting GK today and dealing directly with them. One of their service centers is the next town over. I will keep you posted.

Damaged driver if it does it with a different amp. Does your amp do it when played through a different speaker?

lowrocker · #9 10-13-2011, 11:30 AM

Haven't been able to try head w/ a different cab. Used a different head with my cab and same thing happened. Just in case I set my eq flat and it still happened. It's at the shop and the guy said it could be a blown speaker or just that the glue on the speaker came undone. I should get word by Monday.

Thanks guys

lowrocker · #10 10-19-2011, 05:23 PM

Well I took it to an authorized GK service center and 1 week later after waiting for the green light from GK, he found ......... nothing. He said that he had it cranking and there was no buzz. He also said, because he didn't find anything wrong with it, he is charging me a $45 bench fee, because he is getting no money from GK. Well, I bought BRAND NEW MATED equipment, so I wouldn't have any problems. Now I have to pay out of pocket and nothing has been done. ***!

Now I have to contact GK and see if they can do something about this BS bench fee. Plus I still have gear not working properly. I have to see if this guy can check the head without soaking me for another 45 bucks if he doesn't find anything wrong.

garagebassman · #11 10-20-2011, 08:46 AM

that is kinda lousy....for $45 they/he should at least provide you the opportunity to demonstrate the noise with your gear if necessary.....i'd bring it with me when going to pick it up....will make it very simple.....If You can say "hear that noise ?" , that means "issue not fixed, hence, no $45 for you !"
even if it's to the GC employee(s) (assuming the repair tech is at another off-site facility)

Hope it works out though
And Yes, I would have to say contact GK directly ASAP
I wouldn't expect them to fork out $45 to you, but that almost would cover shipping to get the rig to their factory and straightened out for certain

lowrocker · #12 10-21-2011, 11:20 AM

Thanks for the advice. I did call GK and they said the same exact thing you said. I also called GC again, saying the same thing. I put a call to the off site tech yesterday morning, still waiting for a call back. The guy at GK gave me his extension and told him to call him back with how I made out.

The reason I didn't ship it to GK in the first place was, so I could avoid extra fees like this. Now I might have to ship it after all, depending on what happens when I go to pick up the cab. Maybe I should have bought used equipment?

lowrocker · #13 10-22-2011, 11:48 AM

Well took my head and two basses to the shop and tested it in front of the tech. He heard it slightly and then tested the head through one of his cabs and it made the same buzzing noise in his cab. So it's the head, not the cab. The clipping light isn't coming on, but the signal is breaking up. So, no bench fee as there is a problem that needs to be fixed. I know the tech is very experienced, but this is his first time fixing this head. So, keeping fingers crossed.

Thanks again for all of the input.

garagebassman · #14 10-24-2011, 08:57 AM

Something must have occurred in the amp when you heard that shutdown "pop"
I'd be willing to give the tech a shot at it if he's up for it, since good tech is valuable....
however, I would keep (brian maybe?) the GK rep advised.
I mean, that amp is so small and cheap to ship, GK may make it happen nearly as quick as the tech could (assuming he'd need to wait for a part).
I have heard they can produce some amazing turnaround times for repair.
Any time I've sent out an amp to repair , either need to drive 45min each way and wait a week (but an EXCELLENT tech), or send it out and wait a week or two even...
thankfully it does not happen often !
keep us posted anyway

lowrocker · #15 12-31-2011, 06:45 PM

Sorry it took so long to get back, life has been chaos. Well, the problem was in the head, not the cab. It was isolated to a burnt pre-amp board and is working fine now, go figure?

::::BASSIST:::: · #16 12-31-2011, 07:38 PM

I would not be satisfied with that as it may very well give you problems in the future. If I were you I would return it to gk under the warranty and get them to give it a clean bill of health... or a new amp.

Good luck with it!

lowrocker · #17 01-01-2012, 09:06 AM

I do intend to contact them and ask how the repair affects my warranty now. Thank you for your input. Happy New Year.