GK amp question....

[koogie2k]

Ok my bass bros/sisters.

I have a GK 750, compressor, eq with a power conditioner in my rack. Got a GK 410 cab. I use my Stealth mainly, but have noticed when all is on, I hear a steady hiss from the set up. I have disconnected all wiring to try and eliminate the culprit. Nothing found. I messed with the knobs on the bongo and still get it. So, I wanted to eliminate the bongo completely. I hooked up to my Ampeg practice amp and noticed the hiss. Just to be sure, I plugged in my Lava Pearl bongo and got the same thing. I changed batteries and still have it.

Personally, I have eliminated the bongo as I know it is not the problem. This hiss happens with both of them. My rack is at my drummer's house and my practice amp is at my house. So, I eliminated location of the amp.

Any ideas from anyone? Again, I am sure it is not a bongo related issue. Unless there is something someone knows that I don't. That is possible as I am not a guru by any means.

 

[SteveB]

Koogs, I'm no guru but..

have you tried the cables? Maybe you've got a noisy amp cord, especially if it's longer than 20 feet.

Also, double-check to ensure you've got the right kinds of cables between components... i.e. unshielded speaker cables between the head and the cabinet, and (mono or 'TS') shielded instrument cables everywhere else.

I don't mean to oversimplify, but it sounds like you've covered the other bases (and basses).

 

[koogie2k]

Koogs, I'm no guru but..

have you tried the cables? Maybe you've got a noisy amp cord, especially if it's longer than 20 feet.

Also, double-check to ensure you've got the right kinds of cables between components... i.e. unshielded speaker cables between the head and the cabinet, and (mono or 'TS') shielded instrument cables everywhere else.

I don't mean to oversimplify, but it sounds like you've covered the other bases (and basses).

Ya know...at first I thought it was the speaker cable (I was using a shielded one like a dummy... ), then put an unshielded one in with the problem.

I will check the instrument cable I use from the bass to the amp, but my gig rig is running wireless.....I tried a cable just to see if the wireless was the culprit...alas, it was not the case.

I will however, check the other connecting shielded cables...I got the 3 ft. jumpers brand new, but I have bought new cables that were garbage before. I will go that direction and see.

Dumb question while we are at it.....are there any adjustments in the control cavity of the bongo? Sorry, but I am not near the bongos to check personally...

 

[Motojunkie]

If it's all rack mounted - try removing them from the rack. I've had hum issues as a result of poor grounding. Not likely the same issue, but it doesn't hurt to try it.

Another possible thing is noisy power source. If you have a UPS (computer type) that will handle the current draw of your amp, try it to see if it helps.

 

[koogie2k]

If it's all rack mounted - try removing them from the rack. I've had hum issues as a result of poor grounding. Not likely the same issue, but it doesn't hurt to try it.

Another possible thing is noisy power source. If you have a UPS (computer type) that will handle the current draw of your amp, try it to see if it helps.

Never thought of that. Keep in mind, this is my first rack mounted amp. It is an SKB rack....I don't get the grounding issue with a rack. Again, please excuse the noobieness in me.......

I will check the power source. Could very well be the culprit. Never really thought about that one.

Thanks.

 

[tadawson]

Check your gain structures! If you run the inputs low, and the master high, you WILL get hiss from pretty much any amp. White noise is inherent in electronics, and if you run the preamp low, the signal to noise ratio going into the power amp is also low, and the power amp will bring the hiss up to audible levels. Also make sure that any outboard gear is setup or capable of running at the levels of your bass or effects loop - running a +4 calibrated compressor at guitar level will also induce a buttload of hiss - same issue - gain structure - not enough signal in the device to get very far over it's noise floor.

Having said that, I have a GK 1001RB-II, dBX 160A and a couple of Bongos, and there is a bit of hiss from the Bongo in this combo that does not exist in my passive basses. That's the small price you pay for going active. You might also check the tweeter level (passive crossover or if you biamp) - mine would melt my face off it was so bright initially, and getting it back to a more "normal" sound took down a lot of the hiss as well. (At this point, I still have a fairly bright punchy sound, but if you are more than 8 to 10 feet from the cabs, the hiss is inaudible in a pretty quiet room).

- Tim

 

[phatduckk]

hmmm

dunno dude. what PUP combo are your basses?

have you tried killing the treble?

does the big rig have a horn in the cab that you can turn down/off?

 

[Randracula]

Try these............
http://www.zzounds.com/cat--3135

 

[tadawson]

Try these............
http://www.zzounds.com/cat--3135

Too bad he has hiss and not hum - those won't do squat for a hiss problem . . . .

- Tim

 

[Randracula]

Too bad he has hiss and not hum - those won't do squat for a hiss problem . . . .

- Tim

Alright then, he should try pushing in the tweeter/hi-cut button and turn the presence knob all the way down.Also watch the tweeter volume.I keep mine prettty low.A little goes a long way with the GK amps/cabs.

 

[Dr Stankface]

Amen. I keep my presence cut pretty low and have the tweeter cut pushed in. Still have a little hiss but that's the price i'm paying for this killer tone.

 

[koogie2k]

Alright then, he should try pushing in the tweeter/hi-cut button and turn the presence knob all the way down.Also watch the tweeter volume.I keep mine prettty low.A little goes a long way with the GK amps/cabs.

Thanks bro! That was the ticket. I still have it, but I have to press my ear to the cab...(that is how low it is when volume is at gig level)....I did exactly that with the tweeter/hi cut and the presence.......worked out great and still sounds great. Thanks buddy!

 

[Motojunkie]

I guess that's why I never noticed it with my 1001RBII....I run it biamped with the tweeter volume all the way off.

Glad to hear that someone got it worked out for you.

 

[Randracula]

Thanks bro! That was the ticket. I still have it, but I have to press my ear to the cab...(that is how low it is when volume is at gig level)....I did exactly that with the tweeter/hi cut and the presence.......worked out great and still sounds great. Thanks buddy!

Glad it worked out for you Koogs

 

[maddog]

Good that you got the problem licked.

*scribbles down notes for future reference*