I'm a believer, in de-coupled grounds

[tictac]

Sorry, I’m new to this website and I don’t know how to make those little white box things, so I’ll just have to use quotation marks.

Well I said this…
“I think (Kevin) O'Connor's point is that "Galactic Grounding" is a repeatable method that an inexperienced builder can use to get consistent results, time after time, from one amp to the next; not that it is the "only way" a quiet amp can be built...”

But Mark B said this…
“Which would be nice if it were true. But it's not. Hang around amp boards long enough and you'll have the evidence. Sometimes it works, sometimes it doesn't. If it were that simple, the question wouldn't keep coming up.”

So now I’m saying…
So let me see if I get this straight…What Kevin O’Connor says in the books he writes is “wrong”, but what the “guys-who-hang-out-at-the-amp-board” say is “right”! So that means if Kevin would just stop writing all those “wonderful ideas for building and understanding tube amp” books, and stop wasting his time building world class tube amps, studio equipment, speaker cabinets and so forth; and do what Mark B says “Hang around amp boards long enough” hey, maybe he’d learn the “right way” of building tube amps. Then with his new found knowledge, he could write some more books which explain how to really do things right, and make even better amps than he is now!!!


Then Teo saud this…
I agree with TT "galactic ground" is a good one, I do exactly the same.

Very important the only two chassis grounding points as far as possible.

Teo

And I say…
Thanks Teo for the kind words. Unfortunately we’re both wrong because look what Mark B says next…

Mark B…
“Which goes against what Bob posted just above you. He has multiple chassis grounds.”

Darn-it! Bob must be one of those “guys-who-hang-out-at-the-amp-board” that Mark B was talking about. And since he knows the “right” way of doing things…well Teo, you and me and Kevin, we’re just plain wrong and that’s all there is to it.


But wait! Mark B said what?
“I'll be damned if I can figure this out. I've seen explanations that sound great at first, but always seem to have holes on second thought. We need an amp-building Einstein to figure it out.”

So I sez to Mark…
“Dude, you don’t need an “amp-building Einstein”! Just go and hang out at the amp boards so more! Eventually the answer will come...

Finally Pete C says…
can I be pedantic and suggest that the Galactic ground should really be named the "binary star system"

these amps really are out of this world.........

couldnt resist that

Pete C

Yes be as Pedantic as you want, thanks for the comic relief!!!

Now I think I’ll go read some more of those horrible Kevin O’Connor tube amp books. (shhh… Don’t tell anyone but he’s the amp building Einstein, wouldn’t want to hurt anyone’s feelings)

TT

[MarkB]

Dude


We're all friends here - please keep the hostility to yourself.


Have a nice day.

[Bob-I]

Dude


We're all friends here - please keep the hostility to yourself.


Have a nice day.

Agreed. We're all just hashing out different ideas, trying to learn. You have some good points, but hostility is not necessary.

[tictac]

I don't like hostility either, that's why I tried use humor, guess it didn't come across as funny. But isn't telling people they are wrong instead of agreeing that there could be two different ways to do something hostile too? It sure isn't "friendly"

Teo and I agreed on one way of doing something; so Mark B. if we are all friends here why couldn't you let us have our say instead of telling us we are wrong and to go "hang out on amp boards" so that we can learn something?

I'm sorry but that was plain rude, you've got no idea who I am or my experience level is and if I treated you the way you've done me you wouldn't like it either.

Bob I, my comments in my previous post were not directed toward you; if it came across that way I apologise. If I came across a bit strong realise that I'm a bit frustrated, with people that jump into a conversation I'm having with someone just to say "your wrong" and "I'm right" instead of offering something constructive. I quit visiting a popular amp board because of people like this hang out there and I'm sick of being put on the defensive all the time.

I'm like you guys just trying to learn something new; but I've got things to share now and then too; it would sure be nice to be treated with a little courtesy, I'm willing if you are...

TT

['67_Plexi]

Hey Guys,

If you go back to basic electrical principals, electrons flow from a negative (ground/earth) point to a positve point and not the other way around as a lot of people think. The ground point where the first two filter stages are grounded is basically a 'heavy current' ground where a large current flow is taking place (comparitvely speaking). Grounding pre-amp or sensitive stages (or their power supplies) at this point will make it susceptible to mains hum because of the heavier current flow.

This is also the reason that 'star grounding' is rarely effective in higher powered tubes amps.

Regards !

[Bob-I]

...... I apologise.

Accepted

I'm like you guys just trying to learn something new; but I've got things to share now and then too; it would sure be nice to be treated with a little courtesy, I'm willing if you are...

TT

Excellent. Let's move on and build some great amps.

[Bob-I]

Hey Guys,

If you go back to basic electrical principals, electrons flow from a negative (ground/earth) point to a positve point and not the other way around as a lot of people think.

I've never believed that the DIRECTION of current movement matters. Since no one's really proved it either way I just accept that it moves.

The ground point where the first two filter stages are grounded is basically a 'heavy current' ground where a large current flow is taking place (comparitvely speaking). Grounding pre-amp or sensitive stages (or their power supplies) at this point will make it susceptible to mains hum because of the heavier current flow.

This is also the reason that 'star grounding' is rarely effective in higher powered tubes amps.

Regards !

That makes complete since to me. Star grounding seems to be fine in low power amps, but in higer powered amps it's always been a problem.

I also seperated the filter grounds in my Super Reverb clone and it too was successful. The noise level is down quite a bit, maybe 10Db or so.

[MarkB]

This is very simple. For every builder who says that there's a correct way to ground an amp circuit, there is someone who says that he built his amp that way, it was noisy, he changed it, and the noise went away. Doug Hoffman swears by the Marshall style bus along the back of the pots, which is a series of ground loops and should be noisy. Bruce Collins from Mission amps makes a living by the Fender style brass plate for grounding, which goes against any kind of star ground logic. And if you pull apart a few old consumer audio amp chassis, you'll find a rat's nest of punched tab grounds all over the chassis.
The point is that the theory behind any of the above systems would tend to rule out some of the others - except that they all work. Regarding Kevin O'Connor? I've seen several threads from guys who used Kevin's suggestion and had to change the grounding to get it quiet. Unless they were making it up just to confuse the rest of us, that tells me something. Personally, I followed Kevin's general principle and had no problem. That doesn't mean that it will always work, just that it worked for me in one build.
There's nothing wrong with passing on what you read in a book - I do it all the time. The problem is when you pass it on as some kind of law. Just because a guy self-publishes a book, that doesn't make him God. Many mistakes have been pointed out in Kevin's books, useful as they are.
I responded to your post - no to you personally - because you made a statement of fact that does not, in my experience, hold up. You are welcome to argue with me all you want - that's how we all learn. Just keep the snarky stuff out of it. When you make statements on a public forum, you're going to be called on them. Don't go off all offended, respond with a reasoned argument.

[dogears]

I say do it like Dumble did it...... That is the right way. This is the "Dumble" forum.. no?

['67_Plexi]

I've never believed that the DIRECTION of current movement matters. Since no one's really proved it either way I just accept that it moves.


It's quite ironic you should say that. When I was back in college many moons ago, in electrical principles class the professor would use the operation of a tube to as an example to show how electrons flow from -ve to +ve. It's very easy to understand using tube theory.

Alan.