Error Noise using jack cables without DI box (keyboard)

CQ CQ Troubleshooting
1

Hello,

I recently received the CQ18T and it is generally fantastic; I love its features, and it is exactly what I need. Unfortunately, I am experiencing a problem with my keyboard:

For years, I have been connecting my keyboard directly to the mixer (previously a Behringer XR18) or to the speaker using a standard jack cable without a DI box, and I never had any issues.

Now, I have plugged my keyboard (YAMAHA YC73) into the CQ18T without a DI box, and suddenly I am getting a noise. The noise varies in volume and intensity depending on which menu page I am on with the CQ18T. It is loudest on the fader page.
When I use an XLR cable from the keyboard, the noise disappears. The same happens if I use a DI box. However, I would much prefer to continue using just a jack cable as I have been, since the new keyboard I recently ordered from T (YAMAHA YC61) doesn’t have an XLR output, and I would like to avoid using a DI box.

The strange thing is, if I connect the keyboard directly to the speaker without the mixer, there is no noise. But if I connect the mixer (without anything else connected to the CQ18T) to the second input of the speaker, the noise reappears. So, I can’t connect my keyboard directly to the speaker and use the mics through the CQ18T as I have been because the noise is still there.

It seems to be an issue with the mixer. Do you think it might be a defective unit and an exchange would help? Or am I expecting too much by trying to avoid using a DI box?

1 Like
2

Are you powering all the equipment from the same outlet? Sometimes I notice hum or other noise when I’m in a rehearsal space where the (power) wiring isn’t perfect…
You can avoid grond loops by powering everything from one (the same) outlet.

3

try a TRS (Tip, Ring, Sleeve) cable rather than a TS cable if you aren’t already. :slight_smile:

P.S. the shorter the better without a DI.

4

I use a TRS short cable with XLR on the other end and an XLR longer cable to the mixer.

5

Same issue here, noticeable buzz with jack outputs no DI, clear with XLR. With Yamaha YC73.

6

Are you using a tip sleeve cable or tip ring sleeve cable, the 1/4 inch outs are unbalanced you should be using a tip sleeve cable.

Just wanted to add, that your keyboard 1/4 inch out are unbalanced, other keyboards may be different.

7

Hi Mike, thanks for your reply. I’ve tested with balanced (tip ring sleeve) and unbalanced (tip ring) cables, and both times they give a noticable hum/ticking sound that gets louder depending on the gain and fader levels. I’m not sure if this problem originates in the A&H CQ18T mixer or the Yamaha YC73 keyboard.

8

The TRS from that keyboard is not going to work correctly, how long is the cable? Are you sure TS cable is a shielded audio cable?

9

The YC61 uses unbalanced outputs T/S. It is good practice to use a DI box in this case.

1 Like
10

I believe you are right and I’ll stick to a DI in this case