Just purchased Genz Benz STL6.0-210T COMBO on the Bay from a dealer...

[Lacuga]

...And it sounds awful. Scratchy, static-y, just plain lousy. I plugged in my headphones, and it sounds equally bad. Am I doing something wrong? Is there a problem with the amp, do you think? Any standard tests to figure out what's wrong? Help wanted/needed! Thanks in advance.

[SteveC]

Is it scratchy/static-y when you turn knobs? Distorted? Need more info.

Whatever it is, you can bet the guys at Genz Benz will make it right.

[wave rider]

Ix-nay on the corduroy pants and wool socks!

Try different instrument cord, then a different bass. Does the static noise get louder as you raise the volume?

=wr=

[Lacuga]

It does not sound bad (worse) when I turn the knobs. If I turn up the volume, it sounds as bad, only louder. I tried with another bass, still no good/same problem. I tried with another cord, same problem.

It just sounds muddy, with a buzz at virtually all settings. Needless to say, I am very disappointed.

I appreciate the input/questions thus far. Thanks.

[Aaron_D]

Something is wrong. That rig sounds incredible. Swap out all cables and betteries and try it again. If everything fails contact GB.

[Sav'nBass]

If you just got it contact the dealer you just got it from. Something is wrong. I don't know if GB will honor the warranty etc if it was used.. but if it is new they will and in any case they will be straight up and honest with you, but I'd be contacting the dealer you bought it from first. Those amps are great amps and you should be getting no static. I wonder if it could be the tube.

[agedhorse]

Before jumping to conclusions, let's get some information and work through some basic troubleshooting.

First, is this a new amp or used?

Is there any obvious shipping damage on the box or the cabinet?

Do you have another amp and cabinet available that you can use for troubleshooting?

First thing to double-check is that if you have an active bass, the battery is good. I can't begin to tell you how many times we troubleshoot and discover that it's the battery!!!

Then, tesing the bass into a known good bass amp and cabinet, is the sound ok? If so, let's move onto the combo.

Try the amp into a known good speaker and see the problem remains. If not, then the amp is ok. If it does remain, let's focus on the amp.

If it's the speaker cabinet part ofthe combo, the most common problems are the NL-4 Speak-On not being fully inserted and twisted to lock. Other possible problems are packing materials like peanuts getting into the back of the driver (just yeaterday resolved this with another forumite's NeoX 112). Another possible cause is one of the internal wires touching the back of the cone. I can walk you through this stuff easily iof that's the case. It's also possible that it's a bad speaker, or got damaged in shipping. If it's used, it's possible that the previous owner abused it without you knowing.

If it turns out to be the amp, does it make the noise only while playing?

Try inserting a plug into the effects return jack a couple of times to cycle the return switch inside the jack. Sometimes bits of packing material or other debris gets into the switch contacts.

Does the noise go up and down with the input gain control? With the channel volume control? Master control?

Unplug the speaker when testing with headphones, is the problem still present?

Possible likely causes are the effects return jack or a bad tube.

Let me know more about this and I will help you get it resolved.

[maurilio]

Tube?

M

[Lacuga]

I think you solved it! See responses below, which I followed step by step.

Originally Posted by agedhorse

First, is this a new amp or used?

New, but demo model. Under full warranty.

Is there any obvious shipping damage on the box or the cabinet?

No, although it did not come in original boxes, but it was very well packed by the store.

Do you have another amp and cabinet available that you can use for troubleshooting?

Yes, but I am not sure what to do, other than to confirm that my basses sound fine on my practice amp.

First thing to double-check is that if you have an active bass, the battery is good. I can't begin to tell you how many times we troubleshoot and discover that it's the battery!!!

Passive.

Then, tesing the bass into a known good bass amp and cabinet, is the sound ok? If so, let's move onto the combo.

Bass sounds OK on the old amp.

Try the amp into a known good speaker and see the problem remains. If not, then the amp is ok. If it does remain, let's focus on the amp.

I don't have a way to connect the new amp into the old cab. But the same bad sounds can be heard when I plug in my headphones.

If it's the speaker cabinet part ofthe combo, the most common problems are the NL-4 Speak-On not being fully inserted and twisted to lock. Other possible problems are packing materials like peanuts getting into the back of the driver (just yeaterday resolved this with another forumite's NeoX 112). Another possible cause is one of the internal wires touching the back of the cone. I can walk you through this stuff easily iof that's the case. It's also possible that it's a bad speaker, or got damaged in shipping. If it's used, it's possible that the previous owner abused it without you knowing.

You may have identified the problem! The muddly/craclking sound seems to be affected by the NL-4 Speak-On cable. Playing with that in the back seems to have improved things a lot. Thanks.

If it turns out to be the amp, does it make the noise only while playing?

There is still some static when I turn the Master Volume control.

Try inserting a plug into the effects return jack a couple of times to cycle the return switch inside the jack. Sometimes bits of packing material or other debris gets into the switch contacts.

Done.

Does the noise go up and down with the input gain control? With the channel volume control? Master control?

Now that you solved it, I cannot reproduce the noise, except there is still a small crackle when I turn the Master Volume control.

Unplug the speaker when testing with headphones, is the problem still present?

It was; no longer, it seems.

Possible likely causes are the effects return jack or a bad tube.

Let me know more about this and I will help you get it resolved.

I am going to shut it down and try again tomorrow, to see whether the problem returns. If not I think your surmise was correct: an imperfect NL-4 Speak-On cable connection. I really appreciate your walking me through this. I will report back if there are any further problems. Thanks again!

[agedhorse]

There may be a very slight noise when turning the master volume, it's caused by the detents vibrating the wiper fingers inside the pot as it moves. It should not change volume with time, just you are "hearing" the detents.

If the noise gets worse, let us know and we will take care of it.

While playing, try wiggling the Speak-On to be sure it's not an intermittent connection inside the wire terminals. I don't think so, probably the twistlock not fully seated. This, by the way is common with the Neutrik NL-2 style female cable connector because of the way the collar works. It's kind of hard to feel when it's fully seated. The NL-4FC does not do this but it has a tab that's kind of hard to release if you have big fingers. Oh well.

[Lacuga]

Update: everything in perfect working order. No more noise problems; it was all due to my lack of experience. I really want to thank you for troubleshooting with me. I am very impressed with the service from GB, and an extremely happy customer.

[maurilio]

+1

These guys are the top! Been dealing with GB for a while now and they are super, ALL of them!

M