please comment my pcb

sakis · 5th November 2008, 11:16 AM

zobel network is to be located at outpout connector and return to star ground with a separate cable

Mooly · 5th November 2008, 11:26 AM

Hi Sakis,
The only problem I suspect is if you are making two of these to run off one PSU. If you are you need two ground returns to the PSU star from each PCB. Otherwise the two channels will interact.
If not it's OK

MJL21193 · 5th November 2008, 11:29 AM

Hi,
Looks good! Very nicely organized.
One thing:
You have the input ground direct to the power ground?

Mooly · 5th November 2008, 11:29 AM

Read all of this,
3 stage LIN topology - NFB tappings?

sakis · 5th November 2008, 11:39 AM

Quote:

Originally posted by MJL21193
Hi,
Looks good! Very nicely organized.
One thing:
You have the input ground direct to the power ground?

in fact most of times i did this i had less problems than running ground through 10R resistor

MJL21193 · 5th November 2008, 11:41 AM

Also you could change as I have shown below to avoid that jumper.

Mooly · 5th November 2008, 11:50 AM

Make sure you read that link. It's very relevant

sakis · 5th November 2008, 12:37 PM

i have in mind

never tryied that exact config but will see when pcb is ready

AndrewT · 5th November 2008, 12:53 PM

Hi Sakis,
I have tried various stereo layouts similar to your last post and I could never get them hum and buzz free.
A monobloc where the Audio Ground is on the PCB works OK, but not when you connect more than one channel.

I don't see your schematic but I wonder if the NFB route sends the inverting input from the correct end of the second (lower leg) resistor?
On the same NFB route, it appears to be tapped off the emitter resistor instead of from the speaker output.

MJL21193 · 5th November 2008, 12:55 PM

Quote:

Originally posted by sakis
i have in mind

never tryied that exact config but will see when pcb is ready

This is like polluting your drinking water by connecting the toilet to the water well.

Set up an input signal ground that is isolated from the main power ground.
Return the speaker ground to the main power ground, not on the amp board but on the power supply board. Return the Zobel here too.

5th November 2008, 11:16 AM	#1
sakis diyAudio Member Join Date: Jan 2006 Location: nea makri athens greece	please comment my pcb please comment my pcb zobel network is to be located at outpout connector and return to star ground with a separate cable __________________ SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr

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5th November 2008, 11:26 AM	#2
Mooly diyAudio Moderator Join Date: Sep 2007	Hi Sakis, The only problem I suspect is if you are making two of these to run off one PSU. If you are you need two ground returns to the PSU star from each PCB. Otherwise the two channels will interact. If not it's OK

5th November 2008, 11:29 AM	#3
MJL21193 Account disabled at member's request Join Date: Mar 2007	Hi, Looks good! Very nicely organized. One thing: You have the input ground direct to the power ground?

5th November 2008, 11:50 AM	#7
Mooly diyAudio Moderator Join Date: Sep 2007	Make sure you read that link. It's very relevant

5th November 2008, 12:53 PM	#9
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi Sakis, I have tried various stereo layouts similar to your last post and I could never get them hum and buzz free. A monobloc where the Audio Ground is on the PCB works OK, but not when you connect more than one channel. I don't see your schematic but I wonder if the NFB route sends the inverting input from the correct end of the second (lower leg) resistor? On the same NFB route, it appears to be tapped off the emitter resistor instead of from the speaker output.