I think that EricB made it clear that he knew that the switch was wired wrong and had noted my recommendation. You're on the right track.
EricB there are a lotta positive aspects to using an all wooden case for your project...sonic and aesthetic...I would not shy away from such a concept if you had such a vision. Look at all the boutique amps out there in wooden cases...they charge more for these
EricB there are a lotta positive aspects to using an all wooden case for your project...sonic and aesthetic...I would not shy away from such a concept if you had such a vision. Look at all the boutique amps out there in wooden cases...they charge more for these
What is wrong about the switch and did you read the preface?
I took the picture before seeing what Carlos had said so I explained how I should have wired it and that the picture was not the proper representation.
Answer me this. Does each individual part need to be grounded, ie the transformer, PS, and amp boards or do I just do a main ground?
BTW, he's the one who said to ask a lot of questions. What I am getting is alot of this and that needs to be done. What is the most basic explanation of the circuit and grounding?
I have 5 major components. The power plug, the PS, the transformer, and the 2 amp boards. What exactly is getting grounded? Each piece, one piece, etc...if its one piece why does one get a ground over the other. If its all of them what is the reason for them being grounded. What will happen if they are not. Cause and effect will mean more than "plug that in there".
Carlos,
We picked up a nice black display case with a glear glass top. Ok...lets say I do this. I'll run the ground wire OUTSIDE the case to the house ground. Its right behind the wall plate, where do the grounds get connected inside the case and more importantly why do they get connected there.
Thanks...and I am trying to keep this light hearted. Andrew may have visions of me burning down my house but there is a difference between safety and taking yourself too seriously.
I work with all mechanical and electrical engineers. All I'd end up with is an arguement on how to do it the right way for an hour and in the end we'd just say F'it plug it in and see what happens
We tend to be more on the adventurous side.
I took the picture before seeing what Carlos had said so I explained how I should have wired it and that the picture was not the proper representation.
Answer me this. Does each individual part need to be grounded, ie the transformer, PS, and amp boards or do I just do a main ground?
BTW, he's the one who said to ask a lot of questions. What I am getting is alot of this and that needs to be done. What is the most basic explanation of the circuit and grounding?
I have 5 major components. The power plug, the PS, the transformer, and the 2 amp boards. What exactly is getting grounded? Each piece, one piece, etc...if its one piece why does one get a ground over the other. If its all of them what is the reason for them being grounded. What will happen if they are not. Cause and effect will mean more than "plug that in there".
Carlos,
We picked up a nice black display case with a glear glass top. Ok...lets say I do this. I'll run the ground wire OUTSIDE the case to the house ground. Its right behind the wall plate, where do the grounds get connected inside the case and more importantly why do they get connected there.
Thanks...and I am trying to keep this light hearted. Andrew may have visions of me burning down my house but there is a difference between safety and taking yourself too seriously.
I work with all mechanical and electrical engineers. All I'd end up with is an arguement on how to do it the right way for an hour and in the end we'd just say F'it plug it in and see what happens
We tend to be more on the adventurous side.
Re: ground
That was my thinking...just to protect the user with a chassis ground. For some reason I got a 1Kohm separation but not an infinite resistance "ground lift" as I expected. I guess I'd better hit the books
halo0925 said:...amplifiers offer a ground lift so the system ground is seperate from the earth ground, most of the time the earth ground is only connected to the metal case offering a path to earth incase off accidents.
That was my thinking...just to protect the user with a chassis ground. For some reason I got a 1Kohm separation but not an infinite resistance "ground lift" as I expected. I guess I'd better hit the books
ground lift
Carlos T, check your mains wireing it is possible the neutral and ground are connected at some point in the AC wireing or something is plugged into an outlet that is bleeding to earth ground. Happens alot in older houses and appartments.
Like you stated it should be an open circiut.
Carlos T, check your mains wireing it is possible the neutral and ground are connected at some point in the AC wireing or something is plugged into an outlet that is bleeding to earth ground. Happens alot in older houses and appartments.
Like you stated it should be an open circiut.
Eric_B_C said:
Add a smiley so the folks here know you are staying lighthearted
What to ground...
Power Plug - How? It's made of plastic... The only thing you can do is solder on the green wire to the ground solder lug and bond that wire somewhere...a metal chassis preferably.
Transformer - How? All wrapped in plastic film and already sitting on rubber doughnuts once mounted.
2 Amp Boards - The PG (DC grounds) coming from the rectifier boards are the grounds.
RCA Input Jacks - Now that's an interesting one...
Volume Knobs - Got any? Doesn't look like you got any...
Effectively...if this whole mess goes inside a wooden box, the only exposed items you really need to worry about are the RCA jacks (the outer metal portion...normally considered the input signal ground).
Just from a pure safety standpoint, you gotta think...what can the user touch that'll kill him...what live hot black wire could become deattached that could come in contact with something that a user could touch and kill him...what other appliances are hooked to the amp that could make some part of the amp hot and kill a user. AndrewT brought up a great counterargument to my GFCI/RCD/SKIP THE GROUND WIRE proposal with this last one. You can design and control the power juicing up your amp box and protect your user but can you control the power that may be coming in from other componets attached to your amp? Let's say that a CD player or tuner fails and energizes its chassis. An RCA interconnect to your amp coud get "hot" and shock any user of your amp box. I was actually thinking of a contracounterargument...
Ok, long story short...the ground gives an errant connection a way to discharge the electricity without it discharging into the person handling or touching it.
So in a metal chassis this could be the entire box which would mean very bad. In a wooden or glass chassis its the exposed metal parts, the RCA in's or the speaker outs. No volume control, I don't think you guys could handle those questions yet
It is not, and I know I'll regret saying this, it is not a requirement for the amp to work correctly IF it is wired correctly. It is there to protect you in case the amp is wired wrong or there is some kind of unforseen failure in the future, right?
When I wire in the speaker connections there is only positive and ground, correct?
So lets go back to my original idea.
We really like the wooden box and I have some smoked glass left over from our AV stand so I was going to use that for a base and top cover.
So there is no place to ground the unit at all in a box like that correct?
The proper thing would be to ground it elsewhere, like the ground point behind the wall plate?
If I were to do that, and this question has not been answered yet, where does that green wire go and why???
I'll run a dedicated wire to the wall socket ground point. I have a bunch of 3 prong IEC cables at work that have a seperate grounding strap on them
Its going into a rack on the bedroom, assuming its still standing after I plug this in, and its going to stay there so wiring a dedicated ground is not an issue.
This is my workbench in my office, I'll even run a grounding post from the outlet up here to test it out on...if I knew what to connect to it.
How do other devices do it, do they all have internal grounds or do they use the wall ground via the electrical plug?
So in a metal chassis this could be the entire box which would mean very bad. In a wooden or glass chassis its the exposed metal parts, the RCA in's or the speaker outs. No volume control, I don't think you guys could handle those questions yet
It is not, and I know I'll regret saying this, it is not a requirement for the amp to work correctly IF it is wired correctly. It is there to protect you in case the amp is wired wrong or there is some kind of unforseen failure in the future, right?
When I wire in the speaker connections there is only positive and ground, correct?
So lets go back to my original idea.
We really like the wooden box and I have some smoked glass left over from our AV stand so I was going to use that for a base and top cover.
So there is no place to ground the unit at all in a box like that correct?
The proper thing would be to ground it elsewhere, like the ground point behind the wall plate?
If I were to do that, and this question has not been answered yet, where does that green wire go and why???
I'll run a dedicated wire to the wall socket ground point. I have a bunch of 3 prong IEC cables at work that have a seperate grounding strap on them
Its going into a rack on the bedroom, assuming its still standing after I plug this in, and its going to stay there so wiring a dedicated ground is not an issue.
This is my workbench in my office, I'll even run a grounding post from the outlet up here to test it out on...if I knew what to connect to it.
How do other devices do it, do they all have internal grounds or do they use the wall ground via the electrical plug?
I don't get it...if you're using a 3-pronged power cable and assuming your wall power jack ground is good...why would you need to run an additional external ground wire? This is not a washing machine...
If your box is truly insulated (it can't be entirely sealed though...you need holes in there to cool the chip and heatsink...doncha? )...all made of wood and glass and stuff, you could go two ways:
1- Skip the AC ground altogether...your amp is in effect like a double insulated appliance. Your transformer would have to melt to introduce any lethal power into your amp board and then someone would have to unlucky enough to touch this assuming your fuse/breaker didn't already go off from the overcurrent. You need to hire a statistician to figure out the probability of this all happening
2- Run the AC ground to the ground starpoint of the amp board which is normally where the PG (DC grounds) wire comes in from the rectifier board. Yes...I know...you got two of these. You need to run two green wires from each amp board to meet up somewhere with the green wire from the AC ground.
If your box is truly insulated (it can't be entirely sealed though...you need holes in there to cool the chip and heatsink...doncha?
)...all made of wood and glass and stuff, you could go two ways:1- Skip the AC ground altogether...your amp is in effect like a double insulated appliance. Your transformer would have to melt to introduce any lethal power into your amp board and then someone would have to unlucky enough to touch this assuming your fuse/breaker didn't already go off from the overcurrent. You need to hire a statistician to figure out the probability of this all happening
2- Run the AC ground to the ground starpoint of the amp board which is normally where the PG (DC grounds) wire comes in from the rectifier board. Yes...I know...you got two of these. You need to run two green wires from each amp board to meet up somewhere with the green wire from the AC ground.
Ok not to sound like a moron...but the AC ground is the 3rd wire, as I originally had it in the picture then?
You don't get it, neither did I, I assumed based on the way everyone was talking that that third prong was NOT the ground
So I would run the green wire from the 3rd prong on the power, to the PG+ on each board? There is a PG+ and a PG-. Nothing goes to the amp board, right?
I do not trust my soldering skills on this one, is it ok to use connectors that go over the prongs? That way I know its totally isolated.
You don't get it, neither did I, I assumed based on the way everyone was talking that that third prong was NOT the ground
So I would run the green wire from the 3rd prong on the power, to the PG+ on each board? There is a PG+ and a PG-. Nothing goes to the amp board, right?
I do not trust my soldering skills on this one, is it ok to use connectors that go over the prongs? That way I know its totally isolated.
EricB:
I think that you're getting overhyped here over this "lethal" stuff. Get one of your electrical engineer buddies to come over and show you how tame this stuff really is when you take your time...no need to bury a grounding rod in the middle of your bedroom or anything
Anyway...a ground is also a bad thing in a way...it provides a path for the hot to flow to ground...potentially through your body. The reason you have a grounded chassis is twofold as I see it:
1- It provides a path of least resistance for dangerous hot voltages...less resistance for the green wire versus your body.
2- The overcurrent of the errant hot lead touching the grounded chassis will trip the breaker down in your house breaker panel or your local breaker/fuse (in your amp box). Otherwise the chassis is just energized but not tripping anything.
I could be wrong...I'm just a student of this stuff now
I think that you're getting overhyped here over this "lethal" stuff. Get one of your electrical engineer buddies to come over and show you how tame this stuff really is when you take your time...no need to bury a grounding rod in the middle of your bedroom or anything
Anyway...a ground is also a bad thing in a way...it provides a path for the hot to flow to ground...potentially through your body. The reason you have a grounded chassis is twofold as I see it:
1- It provides a path of least resistance for dangerous hot voltages...less resistance for the green wire versus your body.
2- The overcurrent of the errant hot lead touching the grounded chassis will trip the breaker down in your house breaker panel or your local breaker/fuse (in your amp box). Otherwise the chassis is just energized but not tripping anything.
I could be wrong...I'm just a student of this stuff now
Eric_B_C said:
I believe that PG+ and PG- are joined. Get a multimeter and do a resistance read between PG- and PG+ on each unassembled amp board. I'd imagine that you'd get a beep (0 resistance...continuity...joined). This would mean that it doesn't matter if you pick PG- or PG+ to run your green wire out to the AC ground.
BTW the PG+ and PG- silkscreens ARE on your amp boards...what do you mean "Nothing goes to the amp board...?"
AndrewT said:
I'm a bit scared too.
You are only laying this out to show us what you are going to do when you mount and wire all the components properly? Right.
Definitely get someone who knows about mains wiring to have a look, because it's a bit hard to check everything with pictures. For example, I can't tell the orienation of the IEC socket so I can't tell in the active in on the right terminal.
When you first turn it on, make sure someone is there witnessing what's happening just in case things so wrong. You don't want to injure yourself and not have immediate help handy.
Keep one hand in your pocket during testing.
Always pull the plug out of the wall socket when not testing or you are not in the room. Assume the cat or the next door's neighbours kid is going to turn up when your not looking.
Don't use the off/on switch if it is lying on the table like that. You will end up touching something you should not.
I use DPDT switches, you can never trust who wired the power cable. Be careful of the unused terminal on the switch, if you wire the switch wrong it becomes live when the switch is in the off position. I would remove the unused terminal before connecting any wires to it.
Cover/insulate all mains terminations with heatshrink.
Please be very careful.
regards
I think that he's kinda got it
Yes..you introduced the mechanism of how a house breaker goes off back in Page 2...I just rehashed it.
Hey...if EricB wires everything up correctly, the amp won't remember a thing about this thread and won't hold it against him
EricB the reason you do want to solder is that it is a much more reliable connection and less likely to lead to the lethal "errant hot lead" we keep talking about.
Yes..you introduced the mechanism of how a house breaker goes off back in Page 2...I just rehashed it.
Hey...if EricB wires everything up correctly, the amp won't remember a thing about this thread and won't hold it against him
EricB the reason you do want to solder is that it is a much more reliable connection and less likely to lead to the lethal "errant hot lead" we keep talking about.
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