Hearing distortion in new Oasys

keynote · Post by **keynote** » Fri May 02, 2008 4:16 am

I have owned my 76 key Oasys for about 2 1/2 months now. Early on I began to notice a hard to describe distortion in the sound. I searched this forum and KL and have found only one other post addressing the issue. Unfortunately the post has gone stale with no apparent resolution or recognition from those in power.

I originally hoped the problem was with the headphone amp but I have had the chance to listen to the main outs with the same result. The distortion may be described as harmonic distortion or intermodulation distortion. It is most noticeable when playing the mid and upper ranges of the board. The anomaly is broadband but has more energy in the mid a lower frequencies. It occurs in all programs and seems engine independant but is most noticeable in emulative sounds such as piano, strings and brass.

To duplicate: Use a good set of headphones (my phones are AKG K270) as it will be easier to critically listen. Plug directly to the O's headphone jack to eliminate other audio path issues. For consitency, let's use factory preset Bank A prog 000. Turn off all effects and Karma. Play middle C alone for a relatively clean reference point. Now play middle C and E above middle C simultaneously. Repeat. You may also change your interval as the shift in distortion character may better "reveal" it to your ears. You must listen beyond the piano sound.

Let me know what you find.

RobertPlatinum · Post by **RobertPlatinum** » Fri May 02, 2008 4:21 am

I've got some K701's I will listen, are there any instruments in particular?

keynote · Post by **keynote** » Fri May 02, 2008 1:48 pm

Thanks for the help.

You can hear it in all instruments from all engines. Some are easier to pick out such as piano, strings and brass. If you call up factory preset bank A prog. 000 (oasys piano) and turn off all effects and Karma we can be on the same page.

Thanks again

danatkorg · Post by **danatkorg** » Fri May 02, 2008 10:25 pm

If you hear distortion on all sounds (that is, including sounds which aren't programmed to include distortion as part of the timbre), this indicates either that there is something wrong with the audio system connected to the OASYS (e.g. the equipment itself, the connections thereto, or the settings thereof) or that there is a hardware problem with your particular OASYS.

I'd suggest that you contact your national distributor's product support department; see the link in my signature for contact info.

Best regards,

Dan

keynote · Post by **keynote** » Sat May 03, 2008 7:14 pm

Thank you for the link.

I believe I have ruled out the external audio path possiblity as I am using headphones connected directly to the Oasys' headphone jack. I have tested the phones by listening to my 01/W connected in the same way. No distortion in 01/W using same phones.

Can I assume then that you do not hear the distortion described? I have no real feedback either way yet.

If anyone has taken the time to listen for the problem, please reply with possitive (I hear it) or negative (all clear) so that I can put this issue to bed.

All that said, I will contact support.

Thanks again.

RobertPlatinum · Post by **RobertPlatinum** » Sun May 04, 2008 12:30 am

I've checked. I can hear no distortion even at full loudness on my headphones.

Charlie · Post by **Charlie** » Sun May 04, 2008 8:23 am

I use the same headphones - but I didn't follow your exact procedure. However, A000 is a sound I play quite often - and I've never heard any distortion - neither when playing over Genelecs nor over the AKG. My guess: your O needs some repair, sorry.

keynote · Post by **keynote** » Mon May 05, 2008 2:44 pm

Thank you for taking the time to listen and reply. This is good news for the masses, bummer for us at Keynote.

Thanks again.

Daz · Post by **Daz** » Mon May 05, 2008 3:43 pm

No distortion here through AKG K240's with volume ramped right up.

Kevin Nolan · Post by **Kevin Nolan** » Tue May 06, 2008 1:03 pm

Keynote -

Check with a 2nd pair of headphones - if the impedance of the OASYS headphone preamp is different to that on the OW1 then you may hear distortion on one but not the other (unlikely but you should check).

Also - I would check with external speakers to see if the distortion is on those as well.

You might also try recording something and burning it to interal CD to see if that's distortion free - which may help isolate where in the OASYS the distortion is coming from

Do other tests such as with internal volume levels and inserting/removing effects to see if the issue is there.

Quite often I have found that what initially seems like a critical problem is some sort of curious configuration issue. My nost recent one was that I though my OASYS was problematic on one channel, only for me to eventually discover that, having fallen off my chair, that one of the speakers in my HD650 headphones had moved our of position within the head set housing, was pointing a few degrees away from my ear and making that channel sound a little dimmer!

Kevin.

keynote · Post by **keynote** » Wed May 07, 2008 3:47 am

Thanks Daz and Kevin.

Recording and burning to CD is a great idea. Will do and let you know. In the meantime Korg has helped me find a local repair shop.