I'm hoping someone here can assist me in isolating a problem I'm experiencing when I connect my Yamaha Tyros keyboard to my Motion Sound KP-100S stereo amp via a Hosa 10 foot duo audio cable (with two 1/4" plugs (L/R) at each end).

Here's the problem - With the Hosa cable connected to both the Tyros & KP-100S and both units turned on:

If I jiggle around either of the Hosa's 1/4" plugs plugged into the KP-100S's 1/4" inputs, I hear an awful loud grating crackling noise come out of the KP-100S speaker(s). This annoying sound will also appear intermittently and unexpectantly even when I'm not touching or jiggling the jacks, and with the Tyros powered on, but with its volume knob set at the the minimum volume level (no sound) position.

If I unplug the Hosa cable from the KP-100S, yet leave the KP-100S turned on, the problem goes away completely.

Also, leaving the KP-100S power turned on, keeping the Hosa cable connected to both the Tyros keyboard and the KP-100S, but then turning off the Tyros power, makes the problem go away as well.

Based on the above, what do you guys suspect may be the 'source' of the problem: the Hosa Cable, the Tyros, or Motion Sound KP-100S?

My initial impression that there may be a bad connection (loose fit?) between the Hosa 1/4" plugs and the 1/4" inputs on the KP-100S.

Has anyone else here ever experienced anything like this? Feedback & help appreciated. Thanks.

Scott

I don't own a Tyros or KP100S, Sigh..., but from your description I would guess it's the cables or connectors. 1) Jiggling makes the sound. 2) If either are disconnected or Tyros powered down, then there is no signal on the line to make the noise.
That's my guess, and I'm sticking to it.
Starkeeper

I would have to agree with Starkeeper, as I also
think it has to be the cables or connectors.
Denny

If the cable you are using is not balanced, get a balanced cable.

Hey Scott,

Like others, I'm suspecting the cable and or connectors of the cable.

Flip-flop the connectors...The ends that were plugged into the amp are now plugged into the Tyros and so on. Do you still get the cracklin' but now it happens when you jiggle at the Tyros end? Could be bad cables (at that end). Is it still cracklin' when you jiggle at the amp end? Hate to think it might be the female connector in the amp itself.

Have you tried different cables all together?

Keep us informed.

Good luck!

mike

Are 'balanced' cables the same thing as a single stereo cable with a 1/4" (tip ring sleeve) connection plug at each end?

If so, will connecting two single cord stereo cables like this really work? I had thought that both the Tyros & Motion Sound KP-100S only accept unbalanced (mono) outputs & inputs.

Thanks for futher clarification and help.

Scott

Scott, I had very simlar problem like yours going from my mixer (yamaha 01v) to Yamaha Motif. I was using an un-balanced cable. swapped it out with a balanced cable and everything was fine.

Looking at the cable it looks like a normal stereo cable with tip, ring, sleeve configuration so I also thought that it is the same as standard stereo cable but when I asked the sales person at Sam Ash, where I bought my cables from, he told me that it is not the same. He did explain why but I can't rememeber.

I dont't know about your amp but I will be very surprised if Tyros had unbalanced connectors. I think all pro keyboards have balanced connectors.

Harosha: Interesting to read this.

Can anyone here verfibly confirm if either the:

Yamaha Tyros keyboard

or

Motion Sound KP Amp (KP-100S & KP-200S)

require balanced (tip-ring-sleeve) audio cables or not?

Scott

Does it happin with your EV sxa100 speakers

Scott,

There's a very easy to determine the culprit. First, plug another cable int the KP-100, but do not plug anything into the keyboard. Then jiggle the cable near the connection to the amp and if you get the crackle, the problem is with the amp's 1/4-inch female connector.

If you don't get a crackle, plug the cable into the keyboard, and repeat the jiggling procedure. If you don't get the crackle, then it's those new, custom cables. If you do get the crackle, the problem is likely in the keyboard's 1/4-inch female connector.

Though I've never opened a Tyros and looked at the connectors, I suspect they are ordinary 1/4-inch mono connectors--not stereo. But, even if they were, it would not make a difference when it comes to interference such as the nature you are describing.

In all the years I've been playing, I only had one incident where there was a problem with the 1/4-inch female connectors, and that was due to the accumulation of cigarette tars and nicotine in the inside of the connector. The problem was solved by cleaning the connectors with TV Tuner Contact Cleaner and a Q-Tip.

If your problem is being caused by the cables, which is the likely scenario, send them back and try another supplier.

Good Luck,

Gary