What do you use as ground the most?

[gutsofgold]

I've noticed layouts from GGG use the circuit board as a ground buss. Tonepad uses from a star grounding technique with nearly every ground connection going to the INPUT ground connection.

What do you usually do? Would one be a preferable choice over the other.

[MikeH]

I say it doesn't really matter (in anything I've ever done) as long as you're not creating any ground loops.  I find that the input ring lug gets a little crowded and looks sloppy with 4 or maybe 5 wires hanging of of it, so I generally do a double star-ground, on the input jack and the power jack and then connect the 2 together.

[caress]

i usually ground everything to the 9v jack.  it's usually only 2 connections - board and input jack.  occasionally i'll ground a pot to the output jack if it's close and can be done with a clipped lead... i'm not wiring to my star ground when i do that, though, just through the enclosure -- so i guess in theory i could get a ground loop?  i've never had a problem, though...

[sean k]

Using the input as a star grounding point is an ol' tube amp thing as it's the highest impedance point. It's just good practise, as it were, but it doesn't mean you can't have a bus that then has one earth going to the input.

And as the man says above me the ground loop thing is pretty darned important.

[Boogdish]

If a pot is leading to ground, I'll ground it to it's back, I'll usually do the ground on the switch for the LED to the output jack and do the board to the input jack.

[irishstu]

If a pot is leading to ground, I'll ground it to it's back, I'll usually do the ground on the switch for the LED to the output jack and do the board to the input jack.

Yeah, I ground to the back of the pot too, if the input jack is plastic.

I have a question about the ground loop though. If the box is metal, and it is grounded (doesn't matter where for this question), does the fact that the metal box completely encloses the circuit not prevent any chance of a ground loop from happening anyway?

[R.G.]

Pedals are so small, and usually have such low currents flowing that you get away with grounding schemes that would not work well on bigger things - like tube amps.

Star grounding can be demonstrated to be sufficient to prevent ground interactions. However, the exact physical setup, location of signal wires, currents, impedances etc. can conspire to allow other non-star systems to work as well.

The biggest thing in a pedal is to keep power supply current transients off the input jack ground line. And people often get away with even that sin.

[birt]

i try to ground most to the circuit board. jacks are isolated. the i run a solid core wire from one of the jacks to a corner from the enclosure where it is solered to a small ring that goes around the screw of the lid so the enclosure is grounded. i like this better than grounding through metal jacks.

[GibsonGM]

Hey Irish,

The grounded enclosure acts like a big antenna in a good way...picks up RF floating around in the room and channels it to the 'drain' ground.  Ground loops work differently...there are a  few posts floating around about it in detail, but basically, as R.G. said, you have power transients and you have signal.

When the power is fluctuating (due to current draw, like from an oscillator or opamp, or just insufficient power filtering or random variations in line current), the voltage level at the device ground may not be exactly zero volts.  But your signal ground line probably IS at 0 volts.   These differences in potential between what are supposed to be GROUND lines (0V) can cause a small current to flow, called a ground loop.   Acts like a 2nd circuit in there with your FX, and causes noise.  Think of switch popping, which is also 2 different voltage levels interacting...

What works for me is to ground all board 0V connections to 1 bus, then take that out to the input jack with 1 wire.  Enclosure is grounded thru the input jack, as is the power supply [battery/DC jack].  Never had a ground loop problem this way.

I don't ground the output jack (the enclosure also connects to that thru its sleeve).  Works very well, but you have to be sure your output jack won't come loose!  Use a lock washer on the inside, Loctite too.  And check them once in a while before a show ;o)

[petemoore]

  "How good is the ground" ?
  How 'ground-ey' is it ?
  Does it get greater than 0.0000VDc in it?
  If it does, it is more or less 'ground-ish', and, if that is in a sensative point of signal path and used as ground reference, then it should be considered more or less than ground at times, if that equates to noise then the ground isn't that 'good'.
  In stompboxes, I've done everything from star to messy as heck grounds, looping ground wires from circuit board to circuit board, much the opposite of star ground.
  The insides of stompboxes seem to be mostly immune to ground loops.
  OTOH, the outsides of stompboxes often seem quite particular about ground loops.

[rogeryu_ph]

Hey Irish,

The grounded enclosure acts like a big antenna in a good way...picks up RF floating around in the room and channels it to the 'drain' ground.  Ground loops work differently...there are a  few posts floating around about it in detail, but basically, as R.G. said, you have power transients and you have signal.

When the power is fluctuating (due to current draw, like from an oscillator or opamp, or just insufficient power filtering or random variations in line current), the voltage level at the device ground may not be exactly zero volts.  But your signal ground line probably IS at 0 volts.   These differences in potential between what are supposed to be GROUND lines (0V) can cause a small current to flow, called a ground loop.   Acts like a 2nd circuit in there with your FX, and causes noise.  Think of switch popping, which is also 2 different voltage levels interacting...

What works for me is to ground all board 0V connections to 1 bus, then take that out to the input jack with 1 wire.  Enclosure is grounded thru the input jack, as is the power supply [battery/DC jack].  Never had a ground loop problem this way.

I don't ground the output jack (the enclosure also connects to that thru its sleeve).  Works very well, but you have to be sure your output jack won't come loose!  Use a lock washer on the inside, Loctite too.  And check them once in a while before a show ;o)

+1 very well explained.... with a little side note on your configuration, does connecting another wire on your jack output ground tapped to the jack input ground or direct to the ground bus would introduced ground loop? Just to be safe even your output jack or input jack grounds becomes loose.....also, Loctite may difficult to remove in later modification 
 

Thanks,
Roger

[yeeshkul]

Any time you trace the ground and end up at the point you started from, you have a ground loop. As simple as that.
JACK IN -> CASE -> JACK OUT -> GROUND WIRE BACK TO JACK IN

To avoid troubles with loose jacks do what birt said: isolate jacks from the case, connect their grounds and mount this to the screw on the case. Here, you have to believe the screw won't get loose, hihi. Connecting jack-grounds of mounted, non-isolated jacks may work as a ground loop. With right washers, jacks can get hardly loose anyway - especially when mounted to aluminium case. Nevertheless i have this phobia too - i even fix pots by the side-lock, so they can't spin.

I personally do (with success so far) the same thing as Gibson. But as RG said, stompbox circuits are so small, that "star" grounding (all grounds once to one point) is not as important as in case of amps, where you have large circuit board ...