The problem with sound (volume down)

[pixatu]

Hi guys
I have a problem with my pa3x 76.

when I sing into a microphone connected to the pa3x and cried out loud, the sound of the speaker Paas volume down in a moment volume up.

the headphones do not have this problem.
please help

my os is Version 1.50

[karmathanever]

If you are using MaxxAUDIO make sure you are using the correct Amplification System Preset for PaAS (page 219 in the latest manual)

There are warnings about potentially harming the PaAS if the MaxxAUDIO levels are high.

Don't know if this helps???

Pete

[pixatu]

I using MaxxAUDIO preset for paas ( VOLUME GAIN UP 6)



previously not noticed this problem.

thanks for the reply

[AntonySharmman]

when I sing into a microphone connected to the pa3x and cried out loud, the sound of the speaker Paas volume down in a moment volume up.

PAS integrated amplifier has a protection module as all qualified PA systems
that limits output instantaneously when over drive input level is detected.

Reduce overall volume or insert a limiter effect to delimit your mic level.
Also If you believe that PAS power is low for your needs then use external Pa
system and loudspeakers ,'cause Pas is a low power device just for home monitoring.

Pushing PAS frequently to it's power limits , will soon lead it to destruction.

[pixatu]

thank you friends.

I use korg pa3x a few months, there was no problem.

the problem started 5 days ago

[alfredokiwi]

thank you friends.

I use korg pa3x a few months, there was no problem.

the problem started 5 days ago

Maybe the power amplifier IC blows partially, this is a class D type and normally they don´t use any heatsinks as previous amplifiers for cooling down and.....
My recommendation is to build a custom amplifier board with a heatsink to replace the class D amp device, my point of view.

[AntonySharmman]

pixatu
If indeed during last 5 days ,under same volume you used to work ,protection cuts
audio power , then a close to alfredokiwi speculation can be occurred like partial malfunction
and will be worst as time passes ,up to be fully burned.
Unfortunately I don't own electronic design sheet of this module , (even don't know is is D,E
or lower class) , to be more specific.
Maybe a service center visit could be necessary especially under warranty.

[jonstatt]

pixatu
If indeed during last 5 days ,under same volume you used to work ,protection cuts
audio power , then a close to alfredokiwi speculation can be occurred like partial malfunction
and will be worst as time passes ,up to be fully burned.
Unfortunately I don't own electronic design sheet of this module , (even don't know is is D,E
or lower class) , to be more specific.
Maybe a service center visit could be necessary especially under warranty.

Are the amplifiers in the PA3X or in the PAAS module? I was originally suspecting that the amplifiers were in the PA3X and the PAAS module was just a speaker connection using the pins on the rear of the PA3X.

[alfredokiwi]

Is possible that they use the same output as in Pa500/800. There are two circuits, the first is an 4 stages active EQ and the second that should be replaced the power amplifier class D. Because this is only 1 board for both circuits class D power amplifier should be disconnected and a custom power amp adapted (class B for example 2X TDA2030)

If you want a class D I recommend this board on Ebay, notice that they use a heatsink for safety (I have installed an heatsink on my Pa500 power amp because at factory use the epoxy circuit board as heatsink to cool down the class D device)

http://www.ebay.com/itm/HiFi-Mini-Ampli ... 416bd12f9c

But I strongly recommend to adapt a class B type, is a bit more bulky but more reliable as a D type (will not explode !!)

http://www.ebay.com/itm/TDA7297-15W-15W ... 3f178dbfde

Or you can build it, on internet there are a huge list of sites about DIY 12 volts audio amp.

http://dcimixer.com/electronics-223/tda ... rcuit.html

[Thoraldus]

This is weird ...

The specs for the PA3X state ...

Power Consumption 35 Watt - 50 Watt when connected with optional Amplification Bar (PaAS)

So according to this the PaAS uses a total of 15 watts.

Then the PaAS spec states ...

3 Channel Amplifier: 2x20 Watt (Mid/Hi) + 1x40 Watt (Subwoofer).

( 2 x 20 ) + 40 = 80 watts !!!

Magical! KORG has somehow created 65 watts out of thin air.

I have a feeling that KORG has not read the US FTC regulation "Amplifier Rule CFR 16 Part 432" requiring audio amplifier outputs to be rated in watts RMS.

[Thoraldus]

(snip)

But I strongly recommend to adapt a class B type, is a bit more bulky but more reliable as a D type (will not explode !!)

http://www.ebay.com/itm/TDA7297-15W-15W ... 3f178dbfde
(snip)

Looks like a Class AB amplifier to me Alfred. Cheap! Thanks for the link!

Here's a link to the spec sheet for the bridge amplifier they are using ...

http://datasheet.octopart.com/TDA7297-S ... 837159.pdf

[AntonySharmman]

jonstatt
Pa module is included in Pas box , since costs half the price of whole PAS ,
also rear 4 pin outputs are the proof of this.
alfredokiwi
Your proposals are fair enough for a electronic forum of technicians , since no ordinary
Pa user will ever modify Pa3X to include an external circuit in PAS for god sake !!!

Also Watt references of PAS are calculated in peak power as all manufacturers lately
advertise, since overall W-rms in PAS are mostly 20 W.

[Thoraldus]

jonstatt
Also Watt references of PAS are calculated in peak power as all manufacturers lately advertise, since overall W-rms in PAS are mostly 20 W.

Then KORG should tell us that in the specs and not try to 'imply' the output power is MUCH greater than it really is.

[alfredokiwi]

Normally a class B amplifier is in reality a class AB to avoid crossover distortion. This is the same on IC packages, all are in reality "AB".

[AntonySharmman]

Then KORG should tell us that in the specs and not try to 'imply' the output power is MUCH greater than it really is.

That's absolutely true !