Ringing sound on A4 Key on all Factory Grand Pianos

[jwatson]

Hello,
I am experiencing a ringing sound on my A4 for all grand pianos in the Piano 1 Sound. Grand pianos include German Grand A1, Italian Grand A2, Japanese Grand A3, and the Austrian Grand A4. I do not hear the ringing sound on the Japanese Upright A5. I have tried turning off effects. I have tried turning off the hall effect. I have tried changing the tuning, but then that introduced a beating effect when playing an octave. A repair center suggested I do a factory reset. I did the factory reset through the editor and it did not fix the issue.

I was able to record the sound
https://drive.google.com/file/d/16ExBPh ... sp=sharing

Please help me get rid of this ringing sound.

[voip]

It would be useful to hear a few more notes played either side of A4. There is no clear ringing to be heard on the recording using headphones.

Do you hear the ringing when using headphones? Just wondering if it might be a room or speaker resonance.

.

[jwatson]

Yes, I can hear it in my headphones. It is right at the beginning of the note. It's kind of a cringy sound.

Thank you for taking a look at my problem.

[voip]

Was the recording made using a microphone close to the speakers, or directly from the Line Outs?

.

[jwatson]

The following is the recording I posted above at 0.5 speed. Just the A4 key at vol7, on the Austrian Grand.

https://drive.google.com/file/d/1l0cnKN ... sp=sharing

The following is the notes next to the A4 key. This sound is G4, A4, B4, A4, G4. All at volume 8. Sitting at the piano, phone is about 2ft from speakers. The sound is Piano 1 the Austrian Grand (which happens to be selection A4). The issue sound is most prominent on this Austrian Grand.

https://drive.google.com/file/d/16_F82M ... sp=sharing

I did notice that if I play the recording on my phone you can't really hear the issue sound.

[voip]

All I can hear is a slight low frequency "grumble" type of sound, but that is present on all three notes played in the second recording, and might be a cabinet resonance effect, or a piano body sound. A4 is also louder than G4 and B4 in that recording.

When comparing the first recording with the recording linked to in the original post, the sounds seem to essentially be the same, to my ears at least, with only the slight "grumbling" referred to above, but no ringing, as such.

It's worth considering that the samples used have been carefully recorded, including all the nuances and quirks of the pianos used to make the samples, although one wouldn't reasonably expect three different pianos to have the same quirks.
.

[jwatson]

I took my KORG-SV2S to a Korg repair center. The repairman was also unable to hear it, but he was however able to feel it. The frequency is too high for most hearing. He placed his hand on the left speaker and could feel the vibration on the notes that I indicated were bad. He could identify notes that had it of varying degrees without me saying anything. He said he will contact Korg and see what they would like him to do. The instrument is still under warranty so the repairman said most likely Korg would pay for the repair. The repairman believes that it could be some mounting issue with the speaker, a loose screw, etc. The other things he thought might be the problem is a sympathetic resonance with the case and speakers, which I hope isn't be the issue. I will make another update once I have been given more information or a repair has been made.

[CouchTurnip]

I'm guessing you've had the issue fixed by now, but for anyone else landing here, I'd like to suggest that the tube/valve was the culprit.

TL;DR: If you are experiencing resonance on your SV-2 , take a look at the tube!

My new SV-2 (an 88S with built-in speakers) had the same metallic resonance/buzzing that I can hear in the linked samples. I originally thought it was the left speaker, or some part of the cabinet, vibrating. However, turning off the speakers eliminated the issue entirely, so it wasn't in the electronics or sound samples.

Removing the clear plastic tube cover allowed me to - VERY CAREFULLY! NEVER TOUCH IT WITH FINGERS! MAY VOID YOUR WARRANTY! - place a pencil eraser against the tube, which lessened the resonance considerably.

So I took the instrument back to the shop. After the technician had completely pulled it apart, he pronounced it unfixable. I will note he did not try replacing the tube, as he was convinced it was in the housing. But after he found another unrelated defect, he deemed it a faulty unit, and ordered me a replacement unit under warranty.

The new keyboard does not have the tube resonance issue.

[jwatson]

Korg got back to my certified repair center recently. They are aware of the problem and are coming out with a repair kit soon. If you experience a similar problem to what I have described take your piano to a Korg certified repair center.

Thank you Korg for addressing this. I enjoy the quality of your instruments and now I can say to others that you support your customers.