Hi, I have a numark dxm01 mixer, when i raise the volume on one of the channels there is a noise that resembles radio interference. I've tried cleaning the leads and altering the volume on the amp but it seems to be picking up backround noise from somewhere. I wonder if one of the connections inside have come loose which results in this noise. It doesn't happen on channel 2. Thanks, Ste Patterson

I assume that the power-amp is good.
This noise, of course due to defective parts inside.
But, which section is it? Chances are:

• Amplifier circuit in the Main-Outputs. If the MAIN MIX in the minimum position and still noisy, then the damage in that section.
• At one or several channels. Let's test.
  Set to minimum volume for all channels and MAIN MIX. EQ=flat. FX=minimum. TRIM at half (let's try at 12 o'clock).
  Raise the MAIN MIX, let's say at 15.
  Gently, raise channel 1 volume to maximum, listen, if there is no noise, channel 1 is safe. Lower the volume to the minimum again. Move to another channel in the same way.
  If found noise, that is where the problem is.

Actually, many more detailed steps for testing, but the description is too long. This above is a simple way.
Circuit power supply should also be checked, whether all normal voltage.





It is part of the image of the amplifier section circuit.
Parts which may be broken is the IC 64,65,77.

Hi, i wonder if you solved your problem, because i have exactly the same issue with my Numark 5000FX and i cant figure out how to solve it.
I would really appreciate any help.

What is plugged into your Numark mixer when this happens? Try disconnecting ALL audio inputs to your mixer, turn mixer volumes to zero and see if the hum is still present. Adjust the volume and check if the hum you mentioned returns. If it is still heard, try new cables between the mixer and amp...if not then start reconnecting inputs until the hum is heard again. It's a process of elimination but not that difficult to find the source of your problem.

I do not know this mixer but it is possibly the pan control, it may simply be adjusted to one side. It sounds like the mixer failed.

If you have fader capabilities...and there is still signal "leaking" through...you may try reducing your input gain on each channel of your mixer...as well as make sure you have a good ground connection between your components.

A turntable use a magnetic cartridge and its output is only 5 to 10 millivolts.A moving coil cartridge is even lower,.2 to .5 millivolts(thats 1/2000 of a volt)in contrast, a mp3 puts out a 300 to 900 mv signal..so does a CD player. Your turntable does not have enough signal.You need to get an amplifier that has a phono input. Years ago,radio shack used to sell phono preamps that could plug into a tape or cd input.The other option is to buy a used mixer that has a phono input.The mixer output can drive the cd input easily,as the max output from a mixer is 1.5 volts to 2 volts.

did u find any solution with the mixer? I have a similar problem. Channel 2 works great, Channel 1 is sending only the Left side, something like Mono instead of Stereo.

What do you mean it didn't work? What happened? Are you getting no sound, did the plugs not fit? Please be more specific.

If you are not getting any sound, make sure you connected to the LINE input of the mixer - the PT01 has Line Level outputs, so you CANNOT connect it to the Phono input, as the signal will be too hot for the mixer - so make sure it is in the LINE INPUT. Also make sure the toggle switch on the mixer is set to LINE. There is nothing else to this set up, raise volumes, and that's it. It's very simple.

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This sounds like someting is out of phase. Can you describe all of the connections you have to the amp and speakers. Double check them as well to be sure that the positives are connected to the same terminals on the amp and speakers. If that is OK, we'll start looking inside the mixer.
Dan

Well, it's not that hard to set up. What do you need help with? If you want to know how to connect:

1) The CD units go into the back of the mixer - in the CD / LINE INPUT - Left side on CD / LINE INPUT 1 and Right side to CD / LINE INPUT 2

The output of the mixer - MASTER OUT - goes to the INPUT of your stereo, amplifier, or receiver's LINE INPUT connection.

That's it. Press PLAY on your CD players, and raise the faders/volumes, and your all ready to go.


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