Grounds concept/direction/advice

angchuck · 5th March 2008, 08:19 AM

I have built a number of perfboard circuits, mostly chip amps. I usually built each module as a monoblock, ala chip amp kits; each with its own star ground. They work perfect individually, however in stereo or bridged mode, the sound one channel dominates the other channel.

I believe the problem is the location of common ground because i don't have issues with circuits i build as stereo.

So, in an aid to designing better perfboard grounds, (where ground planes are not possible) Should I:

1) Create 2 star grounds, one for signal and one for power

2) Pull out the common grounds from each channel into a common ground at psu ground

3) Connect both grounds at every possible opportune, ie signal, power and speaker ends.

Any advice/debate would be lovely

Chuck

Puffin · 5th March 2008, 08:23 AM

Are you referring to a Bridged or parallel circuit ? Which chips are you using ?

gainphile · 5th March 2008, 10:56 AM

This is my approach to grounding. Your miles may vary:

Gainclone HUM, THUMP problems - The solution

angchuck · 5th March 2008, 02:06 PM

Quote:

Originally posted by Puffin
Are you referring to a Bridged or parallel circuit ? Which chips are you using ?

Bridged.

My Parallels oscillated too much, i was too lazy to match the chips thinking it was suffice that they were from the same batch.

Chips.. LT1210 (w/servo), LM1785(inverting), LM3785(non-inverting)

Puffin · 5th March 2008, 02:32 PM

I have bridged LM3886's and made two monoblocks ( i.e 2 chips per block) Each amp sounds indentical. You say you have got different gain on each amp ?

angchuck · 5th March 2008, 04:32 PM

I was saying i had bad grounds connections and the uneven balance was a sign.

5th March 2008, 08:19 AM	#1
angchuck diyAudio Member Join Date: Dec 2005 Location: Silly'pore	Grounds concept/direction/advice I have built a number of perfboard circuits, mostly chip amps. I usually built each module as a monoblock, ala chip amp kits; each with its own star ground. They work perfect individually, however in stereo or bridged mode, the sound one channel dominates the other channel. I believe the problem is the location of common ground because i don't have issues with circuits i build as stereo. So, in an aid to designing better perfboard grounds, (where ground planes are not possible) Should I: 1) Create 2 star grounds, one for signal and one for power 2) Pull out the common grounds from each channel into a common ground at psu ground 3) Connect both grounds at every possible opportune, ie signal, power and speaker ends. Any advice/debate would be lovely Chuck

5th March 2008, 10:56 AM	#3
gainphile diyAudio Member Join Date: Dec 2007 Location: Melbourne the sunny city!	This is my approach to grounding. Your miles may vary: Gainclone HUM, THUMP problems - The solution __________________ http://gainphile.blogspot.com

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5th March 2008, 08:23 AM	#2
Puffin diyAudio Member Join Date: Feb 2006 Location: U.K	Are you referring to a Bridged or parallel circuit ? Which chips are you using ?

5th March 2008, 02:32 PM	#5
Puffin diyAudio Member Join Date: Feb 2006 Location: U.K	I have bridged LM3886's and made two monoblocks ( i.e 2 chips per block) Each amp sounds indentical. You say you have got different gain on each amp ?

5th March 2008, 04:32 PM	#6
angchuck diyAudio Member Join Date: Dec 2005 Location: Silly'pore	I was saying i had bad grounds connections and the uneven balance was a sign.