Still getting 'buzzing' through PA

[Mr Bass Man]

I've just got a new (2nd hand) Ashdown ABM EVO 900 III amp and I am running it through my Warwick 4x10
I use an Ibanez TR Expressionist Active 4 string

At Gigs we DI direct from the amp to the desk - with my old Warwick amp I was having problems with constant buzzing through the PA when I did this.
I had the amp looked at and pots fixed - all ok, had bass checked twice - all ok, got new lead - but still had same problems

I borrowed the Ashdown head while my Warwick was being fixed and the guy I borrowed it off decided to sell it, so I jumped at the chance and have since sold my Warwick Profet 5.1

Problem is I am atill getting a buzzing sound through the PA when we DI - sometimes it is hardly noticible, sometimes (like last Saturday) it's very loud.
I did buy a cheap 2nd hand DI box off Trade me last year, but that does nothing.
We ended up mic'ing the cab using drummers old kick drum tripod stand and an old Audix vocal mic - sounded pretty mint out front

I want to get to the bottom of the problem though and don't want to spend good money on a decent DI box - if that's not going to do anything.
I've been tempted to buy a new bass, just because I feel it is 'time for a change', but I actually like the feel of my Ibanez - plus I need to save up some $$ because I want to buy an Ashdown cab to match the amp

I might see if I can hire a good DI box for the night, or hire / borrow another bass from somewhere - just so I can eliminate the problem once and for all

any ideas?

[joppo]

It isn't a ground loop issue is it? I can't remember if this was discussed in your last post. Check on the DI to see if there is a a ground lift switch or button. It will have two settings (off or on). Whichever way it is now, try the other way and see if it goes away. Do you have the bass amp and PA plugged into different wall sockets? If you do, the amp and the PA use differnt 'grounds' (earths) and they can fight against eachother when they are connected through the DI. The ground lift is supposed to fix that.

[BluesBass]

Those AMBs are a nice amp, I used to have a II.
I don't think they have a ground lift button because it has or uses something called a 'floating ground'.
The DI must only be connected directly into a Balanced Microphone input of the desk.

Also... (from the manual - he he he) make sure your XLR plug does not have the shell of the plug internally connected to signal ground or this will connect the system to chassis ground of the ABM and may cause problems with hum - so have you tried using a different cable?

[irvinz]

ground lift?

[Jazzbass]

http://www.rane.com/note110.html

[Mr Bass Man]

Well got to last nights gig (private) DI'd amp through desk and bass started buzzing out front as usual so I tried something - I plugged my bass direct into the PA and it was still buzzing, so problem is definitely with the bass / pick ups! Even tried Drummers DI box with the ground lift on and buzzing is still there.

So my options are to either replace the pick ups / preamp system... but I've got no idea how much that will cost
or
buy a new bass and be done with it

hmmmmm....

[john]

Those are not your only options. It is probably as simple as a bad solder joint on the input jacks ground.

[Mr Bass Man]

Those are not your only options. It is probably as simple as a bad solder joint on the input jacks ground.

well if it was a problem as simple as that then the 3 people who have looked at my bass over the last 1.5yrs would have picked it up?

I had the Rock shop do a new set up on it (intonation, new strings...etc..) in 2012 and they cleaned up the electronics / pots...etc... cost about $60
then last year singer took bass to a repair guy she knows and it cost me $60 to say he couldn't really find anything wrong with the electronics (he did recommend I use a quality alkaline battery)
then I took it to PK Electronics who said there was nothing woing with the wiring / electronics and said a basic DI box would fix any annoying buzz......

I've opened the back of the bass up and can't see any 'loose' looking wires - they all seemed to be connected to something, but I will admit I am hopeless with electronics and wires

I don't really want to keep taking my bass in to someone and pay $$$ only to get told there's nothing wrong with it!
plus my band are booked up just about every weekend until May so I can't be without my bass....

[Harley]

Well, I had an annoying buzz problem many moons back. I tried all sorts of fixes, most of which the OP has mentioned and pthers have suggested.

With my bass having active humbuckers, I ruled out the pups being the culprit. That was until, in a desparate move I did a full copper shielding job on the bass ( even though it had shielding paste in the cavaities ) and star wired the earths. Problem fixed entirely.

[martyforrer]

I had an annoying buzz about 20+ years ago..... so I divorced her.....

[David]

I did a full copper shielding job on the bass ( even though it had shielding paste in the cavaities ) and star wired the earths. Problem fixed entirely.

+1 - I've done this on a few basses now and at $10 per 300m square sheet I think its one of best value improvements you can make to a bass

[martyforrer]

I did a full copper shielding job on the bass ( even though it had shielding paste in the cavaities ) and star wired the earths. Problem fixed entirely.

+1 - I've done this on a few basses now and at $10 per 300m square sheet I think its one of best value improvements you can make to a bass

Agree totally. I solder all the joins in the copper sheilding sheet and run a connecting wire through to the pup routs. Also do the star wiring for the earths. I also resolder all connections, even if they look ok. Being fanatically anal about it is just barely good enough!

[martyforrer]

BTW Mr Bass Man.... just because 3 people looked at your bass doesn't necessarily mean there's not a problem there. See my post above. Did they redo all the solder joints regardless of how they look? Did they replace the output socket with a Switchcraft regardless? If not, your money went down the drain! Just because a bass has humbuckers does not mean it's going to be dead quiet. I've worked on basses with humbuckers that were noisier than single coil basses.

[Mr Bass Man]

BTW Mr Bass Man.... just because 3 people looked at your bass doesn't necessarily mean there's not a problem there. See my post above. Did they redo all the solder joints regardless of how they look? Did they replace the output socket with a Switchcraft regardless? If not, your money went down the drain! Just because a bass has humbuckers does not mean it's going to be dead quiet. I've worked on basses with humbuckers that were noisier than single coil basses.

yeah - I'm just pi$$ed off I wasted about $150 and the problem is not fixed

someone on the talk bass forum said the bridge needs to be grounded too? I am unaware of this... I may have to take it to Mr Glynn - unless someone knows a good repairer on the shore?

[Harley]

someone on the talk bass forum said the bridge needs to be grounded too?

That's imperative!

I may have to take it to Mr Glynn - unless someone knows a good repairer on the shore?

You can easily do full shielding yourself, unless you're an absolute klutz at soldering.

The project will take you half a day. You MUST get the Swithcraft oupt socket that Marty recommends. http://www.guitarbuildersonline.co.nz/n ... -jack.html, but you could try

The self adhesive copper sheet jack http://www.monteallums.com/shielding_supplies.html. Go to the bottom of the page in that link 12" x 12" Adhesive-Backed 1.25 mil Copper Foil.You may need two sheets total.

If you want, you can bring your bass around to my workshop and we can do this together, but I warn you! I have a full range of BFM Jack Lite cabs sitting there which you will not resist trying and once you hear them....that could be disaterous for your wallet.