Do I have a problem with my new GK amp and cabs

[BH12neil]

Hi,

Hope everybody out there in bassland is having a good Christmas and looking forward to the new year.

Here's my question:-

I have just taken delivery of a GK 1001RB-II amp and two GK cabs; a Neo 212II and a Neo 115III. I've wired them up for the first time using the speakon cables provided to find that there is a gentle hissing/hum coming out of both the cabinets, its not loud but it is irritating. I have changed all the leads over in all the various conatations and have tried setting up in the full range mode, none of these actions has illiminated the noise.

Now I am new to this sort of kit and I don't know whether this low level noise is normal or whether somewhere along the line there is a problem with either the cabs or the amp. Common sense tells me that the cabs should be silent but perhaps this is not the case.

I have to say I am really frustrated by it because it has taken months for the amp and cabs to be delivered to me and the last thing I want to do is get involved in returning items if there isn't a problem but if there is, obviously I want to sort it out now. Any advice on what might be the problem, if indeed there is a problem, would be really appreciated.

BH12neil

[icastle]

There's generally a little bit of background hiss and hum - you won't hear it when you're playing.

[LawrenceH]

[quote name='BH12neil' timestamp='1324947529' post='1478738']
I have just taken delivery of a GK 1001RB-II amp and two GK cabs; a Neo 212II and a Neo 115III. I've wired them up for the first time using the speakon cables provided to find that there is a gentle hissing/hum coming out of both the cabinets, its not loud but it is irritating. I have changed all the leads over in all the various conatations and have tried setting up in the full range mode, none of these actions has illiminated the noise.

Now I am new to this sort of kit and I don't know whether this low level noise is normal or whether somewhere along the line there is a problem with either the cabs or the amp. Common sense tells me that the cabs should be silent but perhaps this is not the case.
BH12neil
[/quote]

Background hiss/hum are from the amp, not the cab - though cabs that are more/less sensitive at different frequencies will hide or emphasise it more (typically, cabs with horn-loaded tweeters will hiss more). Hum can be due to mains interference, proper shielding of the bass guitar electronics and in the amp design can help here as can positioning of the kit in relation to interference sources like dimmer switches. If turning the volume down on the bass guitar itself helps, then shielding may improve things.
Very well designed/built amps will have much lower self-noise but in general upgrading to more powerful/more sensitive kit you will hear the background noise more. However the output will be correspondingly much louder as well so it doesn't really matter in most live contexts.

[Oopsdabassist]

Was the bass plugged into the amp at the time?

[daz]

[quote name='Oopsdabassist' timestamp='1324975459' post='1478787']
Was the bass plugged into the amp at the time?
[/quote]

A very good question that is often overlooked, as people often dont try to turn on amp/speakers without having anything plugged in. Which could possibly eliminate bass and leads as a source of unwanted noise, straight off the bat.

[warwickhunt]

[quote name='icastle' timestamp='1324948963' post='1478743']
There's generally a little bit of background hiss and hum - you won't hear it when you're playing.
[/quote]

However 'some' amps have a lot more background noise than others and it is a bug-bear of mine so I'd not give an amp houseroom if it wasn't almost silent when not in use. I have to say that my experience of GK amps is that they are generally not the quietest of amps (not eh worst) and unless you have an excellent clean leccy supply they can be awful! I briefly owned a 1001RB but couldn't get on with the background hiss... sold it sharpish. Saying that many people play GK and never comment on the matter, so it is down to personal tolerance.

As others have said, try your amp without the bass plugged in and also try you amp with another cab as it could be that the horn/top end on the cabs is revealing more than you are used to; why not try other speaker leads as well.

[casapete]

+1 to the above.

I use a GK 1001RB and usually no probs with hum/hiss. However, I recently borrowed a GK Neo212 cab
from a mate, and noticed some hissing. The horn unit appeared very efficient, so I just knocked it down
(or was it 'off!') and no probs. Guess I'm just used to the less efficient horn in my own cab, but TBH even with
the GK cab horn turned up I don't think the hiss was that noticeable when playing at stage volumes.

[BH12neil]

I have tried plugging the bass in and it hasn't impacted on the noise, I have also listened when no instrument leads have been plugged in and its the same. It seems that its the same in all circumstances, the only thing I have noticed is that the hiss doesn't increase with volume which is why I am a little confused.

Thanks for all the comments its really appreciated. I will rig the amp to an Ashdown cab that I have and power it direct from a wall power socket instead of an extension lead as is the case at the moment to see what I learn from that and then I'll report back with the findings. In the meantime any further comments really appreciated.

BH12neil

[Lozz196]

Some brands seem to do this. Hartke springs to mind for me. Exactly as said, the hiss doesn`t get louder with the volume switch, so in a rehearsal room or gig, you don`t notice it, but in a home-use situation, it sounds like many angry snakes are in the room.