Ground noise

Dan_ · Post by **Dan_** » Sat Oct 13, 2012 7:29 am

Hi, does someone experiment a ground noise on his PA3X when connected to a mixer and when you turn the mixer volume up, not with the PA3X volume cursor himself...
Seems that it's coming from the audio outputs because it's not there through the headphones..
I've tried on another system, same result, very annoying.
Thanks for help

Guzicar · Post by **Guzicar** » Sat Oct 13, 2012 7:38 am

I am not sure if we are talking about the same noise here but I get like a very high pitched constant signal/noise coming if i turn the gain up on the channel the pa3x is plugged into, I use a Dynacord cms 1000 mixer. I resolved this by turning the gain only 1/4 of the way up and the turning up the volume slider of the channel up to 0. Then on the pa3x i use the maxx audio EQ etc. to make the pa3x a bit louder and more punchier in sound.

Hope this makes any sense any helps

keysman · Post by **keysman** » Sat Oct 13, 2012 8:45 am

Make sure your output leads aren't coiled on the floor as this can cause a type of induction.

redfox · Post by **redfox** » Sat Oct 13, 2012 9:17 am

I've a noise like your when I plug PA3X to my Dj Tech Cube 201 (low price 280 watts Portable PA System); removing ground terminal from Dj Teach power plug stops noise.
Using my (very old) LEM mixer or my Zoom R24 there is not any noise.

Ciao,
Claudio

AntonySharmman · Post by **AntonySharmman** » Sat Oct 13, 2012 12:07 pm

Dan_
Your problem isn't Pa3X outputs !

Disconnect both Pa3X cables from mixer and raise it's volume to see if hum is by default on mixer !
Then change both Pa3X output cables with brand new and if hum consists then ...
You have a weak and insufficient electrical grounding of your gear , check if common grounding
exists or all connected directly to central (home or studio) main grounding of your power supply.
Don't know what or how ? Call an electrician !

alfredokiwi · Post by **alfredokiwi** » Sat Oct 13, 2012 1:00 pm

Guzicar wrote:I am not sure if we are talking about the same noise here but I get like a very high pitched constant signal/noise coming if i turn the gain up on the channel the pa3x is plugged into, I use a Dynacord cms 1000 mixer. I resolved this by turning the gain only 1/4 of the way up and the turning up the volume slider of the channel up to 0. Then on the pa3x i use the maxx audio EQ etc. to make the pa3x a bit louder and more punchier in sound.

Hope this makes any sense any helps

Maybe the Pa3X is also affected by the "low dynamic range issue" in the same way as the Pa500. Maxx Audio works in similar fashion as the 3 band EQ settings on Pa500/800 with the addition of a "dynamic compressor" to improve output.

Anyway if audio level is low this will lead to dynamic range troubles on every mixer/recordings. To understand my point of view more info here

http://www.korgforums.com/forum/phpBB2/ ... hp?t=75973

www.alfredoblogspage.blogspot.com.ar

Shahin · Post by **Shahin** » Sat Oct 13, 2012 5:07 pm

hi Alfred !
I am familiar with what you did with pa500 and i think its brilliant. i have always wondered if you have informed korg engineers about this and/or introduced your weblog to them regarding this case?

alfredokiwi · Post by **alfredokiwi** » Sat Oct 13, 2012 10:46 pm

Only I can assure the dynamic range issue on Pa500. About the Pa3X demos available on internet are excellent in quality sounding really good. I think due the record feature to a file on SD card and this process is 100% digital, in the same way as the M3 direct mp3 recording. Also I think the Pa3X use DA converters with differential outputs that are much better as the single ended converters in Pa500. Single ended converters are also used on the R3 and Microkorg XL.

The reality about the Pa500 and other synths without direct digital mastering/recording for example M50, TR series, Krome, R3, etc is the small signal degradation on the DA to AD conversion on recordings. And to reach best quality on DA to AD recordings via mixer/sound card is important to have the best analog dynamic range, this is the reason why I have modified the Pa500 (also I have modified the R3 for best dynamic range

).

Here I have recorded 2 new demos

<iframe width="100%" height="166" scrolling="no" frameborder="no" src="http://w.soundcloud.com/player/?url=htt ... "></iframe>
<iframe width="100%" height="166" scrolling="no" frameborder="no" src="http://w.soundcloud.com/player/?url=htt ... "></iframe>

Is important to use direct digital recording when this feature is available because in this way there is no audio degradation on recordings working 100% in digital domain.

Post by **karmathanever** » Sun Oct 14, 2012 4:39 am

Balanced audio cables???

Dan_ · Post by **Dan_** » Sun Oct 14, 2012 5:35 am

alfredokiwi wrote:Only I can assure the dynamic range issue on Pa500. About the Pa3X demos available on internet are excellent in quality sounding really good. I think due the record feature to a file on SD card and this process is 100% digital, in the same way as the M3 direct mp3 recording. Also I think the Pa3X use DA converters with differential outputs that are much better as the single ended converters in Pa500. Single ended converters are also used on the R3 and Microkorg XL.

The reality about the Pa500 and other synths without direct digital mastering/recording for example M50, TR series, Krome, R3, etc is the small signal degradation on the DA to AD conversion on recordings. And to reach best quality on DA to AD recordings via mixer/sound card is important to have the best analog dynamic range, this is the reason why I have modified the Pa500 (also I have modified the R3 for best dynamic range ).

Here I have recorded 2 new demos

<iframe width="100%" height="166" scrolling="no" frameborder="no" src="http://w.soundcloud.com/player/?url=htt ... "></iframe>
<iframe width="100%" height="166" scrolling="no" frameborder="no" src="http://w.soundcloud.com/player/?url=htt ... "></iframe>

Is important to use direct digital recording when this feature is available because in this way there is no audio degradation on recordings working 100% in digital domain.

The fact is when I use digital output, MAXX audio is not available ! am I alone in this case?

Dan_ · Post by **Dan_** » Sun Oct 14, 2012 5:35 am

karmathanever wrote:Balanced audio cables???

Unbalanced...

alfredokiwi · Post by **alfredokiwi** » Sun Oct 14, 2012 1:09 pm

The fact is when I use digital output, MAXX audio is not available ! am I alone in this case?

This unfortunately situation happens on another "EDS" PCM synth chips for example EMU8000 synth with its spdif out tat runs on Sound Blasters AWE 32.

The effects unit runs after spdif output that only stream the PCM samples raw data. The effects unit is a DSP controlled by software algorithms and Maxx Audio is an "add on" effect for the Pa3X.

The only way to have SPDIF with effects is to install a hardware chip DAC 3 wire interface to SPDIF converter. Working 100% digital avoids the add of noise and leveling issues of analog stages.

The fact is that Maxx Audio is not Maxx Audio at all !!!

fResH_ · Post by **fResH_** » Mon Oct 15, 2012 11:12 pm

+10

alfredokiwi wrote:The fact is when I use digital output, MAXX audio is not available ! am I alone in this case?

This unfortunately situation happens on another "EDS" PCM synth chips for example EMU8000 synth with its spdif out tat runs on Sound Blasters AWE 32.

The effects unit runs after spdif output that only stream the PCM samples raw data. The effects unit is a DSP controlled by software algorithms and Maxx Audio is an "add on" effect for the Pa3X.

The only way to have SPDIF with effects is to install a hardware chip DAC 3 wire interface to SPDIF converter. Working 100% digital avoids the add of noise and leveling issues of analog stages.

The fact is that Maxx Audio is not Maxx Audio at all !!!

AntonySharmman · Post by **AntonySharmman** » Tue Oct 16, 2012 10:43 am

Dear mates all these are irrelevant of hum noise that "Dan_" faces !

Pa3X outputs are 6 db lower from its predecessor Pa2X , but also noise floor is 6 db lower too,
so Maxx audio gain comes to equalize this difference if needed !
Maxx audio is a final stage dsp applied to analog outputs like using an external rack connected at outputs.
Though Treble/bass/stereo expansion Dsp "features" remind me of 90's Aiwa combos and I never use them
since they can easily misrepresent a Pro-remix of an experienced style developer , on the contrary multi
parameter equalizer is "the best shot" there and extremely useful to equalize different Pa gears
for our live performances in any missing detail.

A technician owner of Pa3X (not Pa-Whatever) can use advanced lab equipment as I have , to explore
noise froor of analog components to understand why external DAC is not required for Pa3X.
Pa3X Dac is the best Dac I've ever heard from any sampler even from KronosX.
I heard nobody complaining about 40 times raised noise floor of best preamplifier you can buy
or D-class Pa , where is the missed important issue of floor noise !