G&K Problem - Tricky one...

[ptg]

Okay, here goes....

I have a 700rbII running a 410sbx cab.

About a year ago (at that time it was a year old) it died on a gig. After much round and round, it was the 4-pin stereo speak on to speak on cable that was bad.

I thought that was odd but....

Now, about 8 months later, amp dies. Tried not going bi-amp and it works fine.

My tech says those cables only last about a year. I told him I can't believe that these $50 cables only have 50 or 60 uses in them. You'd have people buying cables left and right.

I call G&K and they tell me there is an IC chip on the heat sink that works with the tweeter. If the chip is bad it will send current out and blow the cable.

My tech says, "No way." He said that if that happened you would see smoke due to the high current. Plus, he checked that the first time and it's fine. He still thinks it's the cable.

I call G&K back. Now he says that a couple of years ago they had 2 transistors that were oscillating (Q11 and Q14) and that could cause the cables to cut out. He said that they have no problems with the cables in general and that he has used the same one for the last 3 years.

I tell my tech (who is very far away) about the transistors and he said, Well, maybe, I guess. I could check it.

Ugh.

Any help would be appreciated!! Thank you! Thank you!

 

[BassmanPaul]

I've been using my Speakon cable for more than a decade. Speakons are much more durable than the obsolete phone jacks. The points in your post make absolutely no sense to me.

Paul

 

[ptg]

That's why I am confused.

It will always run with a 1/4" jack to speak on or 1/4" to 1/4" but dies when running bi-amp.

 

[Slevage]

It's not the cable-- unless there is a bad connection in the cable.

You'd see smoke if there was enough current to burn a 10 to 14 gauge wire open (like about 50 amps).

Most likely something electronic.

The old saying is that all electronics run on smoke- wires have lots of smoke in them, fuses have less.

John

 

[4Mal]

I call G&K and they tell me there is an IC chip on the heat sink that works with the tweeter. If the chip is bad it will send current out and blow the cable.
...
...
I call G&K back. Now he says that a couple of years ago they had 2 transistors that were oscillating (Q11 and Q14) and that could cause the cables to cut out. He said that they have no problems with the cables in general and that he has used the same one for the last 3 years.

I thnk maybe you misunderstood the tech at GK as that first point makes no sense at all... either that or the janitor picked up the phone ands was messing with you Probable he meant that if hte IC was bad, it will send out DC current and blow the tweeter ... more or less you need a welder to blow the cable ...

If you take apart your speakon cable you'll see that the wires are held into place with a screw down mechanical connection. As things that are made can do, once in a while the screw down loosens up and a wire backs out. Not often but it is possible.

The second point makes a lot more sense as it sounds more like the tweeter amp or maybe the crossover is having troubles - those two IC's. I would get it to a GK service center and have them go through that section of the amp. You might also contact Gk Customer Service as if it is a known issue, maybe they'll cut you some slack assuming you;re out of the standard warranty. They have treated me very well over the years and I'd say that call would be worth a shot.