Gainclone HUM, THUMP problems - The solution

[gainphile]

You're most welcome !

This is nothing new as I got the information from those links at the start of the article. Just emphasizing few critical points.

Of course there are more elegant and simpler way like using good PCB but I think the concept is the same.

[AndrewT]

Hi Gain,
I think Tom has explained the Safety implications well enough for you to take action AND modify the diagrams in post1.

[danielwritesbac]

Hi Gainphile! I'm so curious. What are the 8 little green Tracon 100v Polyester caps, and what do they do to the bridge rectifiers? It looks cool. . .

[valleyman]

Thanks, very helpful post. I'm about to assemble a couple of chip amps and was wondering about grounding. You've solved my problem

[gainphile]

Hi Gainphile! I'm so curious. What are the 8 little green Tracon 100v Polyester caps, and what do they do to the bridge rectifiers? It looks cool. . .

They are snubber capacitors. Supposedly to surpress HF ripple but I really don't know what they do. I just followed the diagram from:

http://diyaudioprojects.com/Chip/Syn...lone/index.htm

[Mike514ml]

Thanks Gainphile and everyone else for the excellent posts.

I've got a couple of newbie questions.

I realize that the exact wire gauges may not be critical, but could you give me an idea of the relative sizes of the small, medium and huge ground wires?

Also, I'm currently finishing up a BrianGT 3875 dual mono chipamp kit (it's been lying around here for a LONG time), and was wondering if it would reduce the hum and thump potential more if it's built with single or dual power supply boards.

GooTees' 'antiparallel' diodes had me a bit confused, so I Google'd 'audio safety ground disconnect' and came across a page on the ESP site with a wiring diagram. I assume that this is what you meant when you talked about adding a bridge rectifier and capacitor?

http://sound.westhost.com/earthing.htm

Again, thanks everyone. This post has got me interested in putting together a hand-wired, thumpless 'black' amp next. That way, the next time my wife asks me what we're going to do with all of my speakers, I can tell her not to worry, I'm building amplifiers to power them

Mike514ml

[gootee]

Originally posted by Mike514ml
Thanks Gainphile and everyone else for the excellent posts.

I've got a couple of newbie questions.

I realize that the exact wire gauges may not be critical, but could you give me an idea of the relative sizes of the small, medium and huge ground wires?

Also, I'm currently finishing up a BrianGT 3875 dual mono chipamp kit (it's been lying around here for a LONG time), and was wondering if it would reduce the hum and thump potential more if it's built with single or dual power supply boards.

GooTees' 'antiparallel' diodes had me a bit confused, so I Google'd 'audio safety ground disconnect' and came across a page on the ESP site with a wiring diagram. I assume that this is what you meant when you talked about adding a bridge rectifier and capacitor?

http://sound.westhost.com/earthing.htm

Again, thanks everyone. This post has got me interested in putting together a hand-wired, thumpless 'black' amp next. That way, the next time my wife asks me what we're going to do with all of my speakers, I can tell her not to worry, I'm building amplifiers to power them

Mike514ml

Yes. Figure 3, IIRC.

[gmilitano]

Originally posted by gainphile


They are snubber capacitors. Supposedly to surpress HF ripple but I really don't know what they do. I just followed the diagram from:

http://diyaudioprojects.com/Chip/Syn...lone/index.htm

Those small bypass caps on the rectifier bridge reduce the diode switching noises and results in cleaner DC.

[AndrewT]

I see that the Safety Earth connection is still shown wrongly in post1.
When are you planning to ask the Mods to substitute a safe diagram?

[gainphile]

I got the diagram with no 5W resistor. How do I update the diagram?