GK 700RB - dead or alive

I once plugged my bass into the bass boost switch instead of the input jack of my GK 400 RB.

No sound at all, I thought it was toast.




Also, check the mute, is the tuner out working?

 

I just noticed you are in the UK.

Could it be the input volatage, US 110V/60Hz vs whatever it is you guys use over there?

 

Well, lets see. Nothing plugged into the effects loop, right? OK, then . . .
bass into "Input", mute switch off . . . pre-volume not at zero. Main volume(s) (on right side) above zero . . . . cab plugged into "output" jack . . . that should do it. Do you hear any faint background hiss or any other noise from the cabinet once the amp powers up? (On my 1001RB-II, I get a real faint hiss . . . no matter what the level controls or mutes . . . )

If no noise/hiss at all, then I would think that the cable/cab/output hookup is wrong. Since you have tried two heads, I am not inclined to think bad amp section, but two duds is not impossible. If you have a hiss (or other noise), then the problem is upstream of the power amp - preamp/input jack/intrument cable/or the instrument itself.

If you have the volume really low, and touch the tip of the instrument cable with your finger, so you hear a hum? If so, the problem is in your bass . . .

Oh, and on the new one, I am assuming a 700RB-? If so, what color is the power light once it comes on? On the 1001, it is red if in protect, and blue when ready to go . . . .

- Tim

 

Now that I think of it, it can't be the power as the power LED turns on.

I would now agree with Tim and suspect the bass to amp or amp to cab connection. Try using something other than the supplied GK speakon cable. I think this cable may only work with GK cabs. Use a standard speakon or better yet try using the 1/4 inch connection to your cab.

 

do you have the woofer vol turned up last knob on right side under bi-amp output

 

No, the "woofer" volume acts as the master volume when you're not using the G-K bi-amp system. I think that's the problem, but also you mentioned you used instrument cables to connect head to cab. You need to use speaker cables. I doubt it, but maybe instrument cables trigger G-K's protection circuitry.

Also, the speakon-quarter inch cables you tried might not have had the proper connections to use the G-K in full range mode. If the speakon has 1+ and 1- pins, it should work though.

 

how are they connected? when I run 2 cabs,I use 1 1/4"-1/4"
cable from head to 1st cab, second cab speakon cable from head to 2nd cab.

 

Try everything with 1/4 inch jacks. I have rewired the speakons on my Avatar cabs for my GKs, but they didn't work before that.

Good luck! I love my GKs.

 

when I bought my head I was only doing 1 type of gig.All I used was the aggie 1-12" with the head set on top so I just got the shortest 1/4-1/4 cable GS had 3'. when I bought my 15" M123 had a closeout sale on speakon cable so I bought a 10'. most times I use 1 cab or the other and use what ever cable is connected to it,but when I need to rock-it I connect both cabs with the cables I have.

 

For what it is worth, GK speakon cables are dead stock, generic, biamp capable cables which are totally interchangeable with any other standard cable. A two wire "music store" cable is identical, except it does not have the second pair for the tweeter . . . .

- Tim

 

Hey! They beat me to it - that was the second volume control I was referring to in my initial post, but forgot the specific label! The one on the left is the preamp in level, and as others have said, the two on the right control the two sides of the amp in biamp - woofer for low (or full range, if tweeterless cab) and tweeter for the 50W high end amp.

Glad to hear that all is well!

- Tim