Help with active !

[Treva]

Guys I have a cort curbow 5 strings and it's active wich means 9v batteries.
As I use it only in my studio,keep buying batteries is crazy so I tried to use a 9v ac adapter and a loud noise was heard.
Could you guys tell me why is that happening and how could I use an adaptor without that noise?
It's working perfectly with batteries so there's no short.
Really thanks.

 

[David Jayne]

Are you sure the output from the adapter is DC and not AC? Could be either, and it must be DC. If that's OK, then it's a matter of getting a better quality one. Many cheap ones will let a lot of hum through(I'm guessing you heard 60Hz hum).

 

[Treva]

9V DC 300 mA from a zoom pedal.
Well that noise is really louder than the bass sound itself.

 

[bongomania]

Did you get the + and - wires mixed up? Was the noise a "humming" (mmmmmm) or a "hiss" (sssssssss) or a "buzz" (zumbido)?

 

[Treva]

Wires are ok.
I think it's a humming.

 

[bongomania]

Exactly how did you connect the adapter to the preamp?

 

[Treva]

through that battery clip wich comes with bass,my adaptor has it too.
I changed wires and there are 2 options= 1- no sound
2- loud noise(hum)

 

[bongomania]

Is the adapter larger, like a traditional older Boss PSA style adapter, or is it a smaller modern "switch mode" unit like the One-Spot or Godlyke Powerall?

 

[Treva]

It's like that boss but I don't know the others you told.LOL
Yeah I know I'm not helping you but it's just a regular zoom 9V adaptor wich works with dozens of equipments wich needs 9V.
So I'm lost.
Maybe cort is one of those ****er companies who created a special adaptor for that pre and it costs only 300 dollars lol

 

[bongomania]

Sorry for asking so many questions, but do you have a multimeter? (For measuring DC voltage and also checking continuity)

 

[Treva]

Man you can ask whatever you want cause you're trying to help me.
I had it but somebody stole it.
But if that adaptor works with so many equipments including zoom,why doesn't it works with my cort?
What's your theory?

 

[bongomania]

I don't have a theory yet. It's a mystery. But whenever I have a technical problem, using a multimeter to test voltages and continuity can help a lot.

The only guess I have right now is that maybe the Zoom and other devices that the adapter works with have good noise filtering in their circuits, and the Cort onboard preamp probably doesn't have any noise filtering.

Maybe you can borrow a different 9VDC adapter from a friend and see if it makes the noise or not?

 

[Treva]

I agree if bass works with a battery so the problem is in the adaptor.
I was thinking maybe that pre needs a specific adaptor .
As cort site says nothing about it and they even give an email for questions,I thought here maybe someone tried to do that and had the same problem.
Really apreciated your help.
Look your pm.

 

[Fred19137]

it is just a cheap power pack

 

[HogieWan]

the reason it works with the zoom pedal is that the pedal conditions the power before using it.

A quick search found this thread:
Invalid Link Removed

 

[Treva]

it is just a cheap power pack

So let's assume my adaptor is crap.
Going to stores and trying all adaptors till find one wich is good to my bass is CRAZY !

 

[HogieWan]

a battery works because the power starts as DC. The adapter has to take a 60hz wave and make a straight line out of it. Some noise is left over (usually 120hz hum) that needs to be filtered by whatever uses it. Batteries are ALWAYS quieter than audio equiptment that uses AC

 

[Treva]

a battery works because the power starts as DC. The adapter has to take a 60hz wave and make a straight line out of it. Some noise is left over (usually 120hz hum) that needs to be filtered by whatever uses it. Batteries are ALWAYS quieter than audio equiptment that uses AC

Hmmmm....ok but.............where's the answer to my problem?

Just kiiding man

 

[HogieWan]

post #15

 

[Treva]

Ok thanks for your time helping me.
Really apreciated it.