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

Scott,
You can't use Speaker cables for line out/in!
This is how your problem sounds combining the fact that If I recall" in your earlier topic you mentionned someone wanted you to use high quality speaker cable?

To explain why you can't and also the explantion in differences between balanced and not balanced cables, just click on the following link.
http://www.guitarnuts.com/technical/cords/index.html http://www.wpi.edu/Academics/Depts/HUA/TT/TTHandbook/sound/bal-unbal.html


[This message has been edited by freddynl (edited 04-30-2003).]

Scott,
Hosa cables are bargain material, and while they work for most purposes ..... they are hardly the best choice for a high end system. As a side note ..... cell phones can produce noise in speakers that are close by .... turn off those phones on stage people ! (NO one needs to be reachable ALL the time)

Scott,

Possible causes :

Sensitivity :
What is the sensitivity of the KP100S system ? Is it "line" (300mV) or "mic" (10 mV) ?
Your Tyros has line-outputs, so be sure the KP100S has the right match.

Ground-potential :
I expect the KP and the Tyros both have a 'ground-connection' thru the mains-connector. There can be a small potential-difference at both ends of the signal cable, because of electronic circuits. Sometimes they create hum or clicks. Try to connect one of your machines to a NON-grounded wall outlet.

Cable-quality :
Using inexpensive cables can cause crackling because of capacity-variations (condensor-alike) Even moving the cable somewhere, far from connectors, can produce noise.

Balanced cables ? :
If your Tyros has no balanced outputs, using balanced cables does not help much. For optimal use of balanced cables both machines have to be equiped with balanced IN- & Outputs

Roel

[This message has been edited by Roel (edited 05-01-2003).]

Scott ,


I would definately buy better cables .

Hosa cables are "bargin" cables , even if they have performed flawlessly , sooner or later they (hosa) just "go bad" .


Dano

Dave, that's how I know when I get a phone call--the speakers buzz real loud. I keep expecting that call from Nashville, or at the very least Hollywood. I'd sure hate to miss it because I turned my cell phone off.
DonM
Just in case someone thinks I'm serious--

Followup:

Thanks to everyone for all the terrific feedback and suggestions you've given. After running everyones recommended tests, I had my Tyros & KP-100S runnning for many hours yesterday without a hint of noise interference, so I suspect that the problem may have been due to 'outside' signal interference (shortwave radio broadcaster, cell phone or?). In fact, I spoke with neighbors who said that they too had experienced similar intermitent noise over their speakers. btw: Over the EV SxA100's, but with different cables, no noise interference was ever experienced. I hope that purhcasing better quality cables will solve the problem going from the Tyros to the KP-100S.

On the subject re appropriate cables to buy, I've now determined (with everyones help here of course, thanks , that speaker cables are NOT the right ones to get, but that shielded line level instrument patch cables (unbalanced) are the appropriate type to buy. btw: I confirmed that the Yamaha Tyros' have 'unbalanced' line level outputs.

After calling back the GigCables.Com sales rep again and explaining more clearly that I need a duo 2 channel cable to connect from my Tyros keyboard to a powered amp Motion Sound KP-100S, (NOT directly to a speaker), he advised that their model "DHCG" dual channel (stereo) 18 gauge (unbalanced) shielded patch cable (which includes two 1/4" connectors at each end) is the correct cable to get for this purpose:
http://www.gigcables.com/CNpatch.html

I plan to get the 15 foot version. I expect (hope) that this high quality cable will effectively shield the interference noise I was experiencing with the Hosa. I'll let you know the results. Thanks again to everyone for all the valuable feedback and help you've given. This forum continues to be a best place on earth where great musical minds meet. Afterall, we're all here, right?

Scott