EMG Active Pickup Circuit?

slammer88 · Post by **slammer88** » 05 Jan 2012, 19:54

ups..i think i've forgotten the add the sound clip haha

http://dl.dropbox.com/u/7305927/example.mp3 here it is..

deltafred · Post by **deltafred** » 05 Jan 2012, 21:16

That sounds like an earthing/grounding fault.

Very difficult to say what it is without having the guitar here but the common problems are one or more of the following :-

Bridge ground missing
Grounding fault in cavity
Faulty guitar lead/chord
Faulty amp
Faulty mains lead/chord
Faulty earth on mains socket
Some other obscure fault

It could be any of these, my money is on a missing bridge ground. Time to break out the multimeter.

Was your guitar ok before you fitted the preamp?

slammer88 · Post by **slammer88** » 05 Jan 2012, 21:29

deltafred wrote:That sounds like an earthing/grounding fault.

Very difficult to say what it is without having the guitar here but the common problems are one or more of the following :-

Bridge ground missing
Grounding fault in cavity
Faulty guitar lead/chord
Faulty amp
Faulty mains lead/chord
Faulty earth on mains socket
Some other obscure fault

It could be any of these, my money is on a missing bridge ground. Time to break out the multimeter.

Was your guitar ok before you fitted the preamp?

Yes, was ok, i've never played with the bridge-ground cable. I'm using my guitar thru my sound card, and thats all, there's not any other hardware in the chain. Actually, its not as worse as it sounds. Isnt it true that, when the player touches the guitar strings, the humming disappears because the circuit is being completed thru the body? If yes, this issue aint more than that

slammer88 · Post by **slammer88** » 05 Jan 2012, 22:29

By the way, i've seen that, my guitars output jack is a stereo one, whose ring and sleeve lug's are connected. Shall i do anything to prevent battery drain or just let it stay ?

CHEEZOR · Post by **CHEEZOR** » 05 Jan 2012, 22:42

Not sure if this is relevant in this situation, but the EMG installation guides always say to not have the strings / bridge grounded to protect the player from shock hazards. I have also heard that EMG pickups have some kind of conductive material in the black cover that makes them shield the pickup from noise. I'm not sure how true that last part is, but I heard it from someone who supposedly used to work for EMG years ago. He seemed like he was telling the truth, but you never know.

deltafred · Post by **deltafred** » 05 Jan 2012, 22:55

Have you tried measuring the bridge to jack body resistance?

slammer88 wrote:Isnt it true that, when the player touches the guitar strings, the humming disappears because the circuit is being completed thru the body? If yes, this issue aint more than that

Which body, the guitar's or yours and competed to where?

On any of my guitars or basses I can take my hands off without ANY noise increase. (I run 1000W of bass amp behind me, any buzz is too much buzz.)

Single coil pickups can pick up magnetic interference but that is a completely different problem, touching the strings will make no difference.

deltafred · Post by **deltafred** » 05 Jan 2012, 23:13

CHEEZOR wrote:Not sure if this is relevant in this situation, but the EMG installation guides always say to not have the strings / bridge grounded to protect the player from shock hazards. I have also heard that EMG pickups have some kind of conductive material in the black cover that makes them shield the pickup from noise. I'm not sure how true that last part is, but I heard it from someone who supposedly used to work for EMG years ago. He seemed like he was telling the truth, but you never know.

If you don't ground the bridge with normal pickups you will (probably) get buzz. Not sure about EMG, never used them.

I always use an RCD/ELB/whatever they are called in your country as I have had a 240v AC shock through a mic while holding an earthed guitar and it is not pleasant (back in 1968). I am ultra careful now and have a mains test plug permanently plugged into an extension block near me on stage. If I don't get the 2 all clear lights on will not plug anything in. Fortunately this has never happened, yet.

CHEEZOR · Post by **CHEEZOR** » 06 Jan 2012, 04:28

deltafred wrote:If you don't ground the bridge with normal pickups you will (probably) get buzz. Not sure about EMG, never used them.

You are absolutely correct when dealing with normal pickups. I actually bought an LTD with active EMGs in it and when I changed out the pickups I had to drill the hole from the control cavity to the Les Paul style bridge post so I could run the wire because they didn't need that connection from the factory since you aren't supposed to wire it that way. You can google and find TONS of people bitching about this online. lol

bajaman · Post by **bajaman** » 06 Jan 2012, 05:37

the problem is that he has not connected the series connection of the two coils to ground

bajaman

slammer88 · Post by **slammer88** » 06 Jan 2012, 09:10

deltafred wrote:Have you tried measuring the bridge to jack body resistance?

slammer88 wrote:Isnt it true that, when the player touches the guitar strings, the humming disappears because the circuit is being completed thru the body? If yes, this issue aint more than that
Which body, the guitar's or yours and competed to where?

On any of my guitars or basses I can take my hands off without ANY noise increase. (I run 1000W of bass amp behind me, any buzz is too much buzz.)

Single coil pickups can pick up magnetic interference but that is a completely different problem, touching the strings will make no difference.

human body

slammer88 · Post by **slammer88** » 06 Jan 2012, 09:39

I've measured the resistance as you told me..It shows ~250 ohms between output jack's outer shield and bridge. What now ?

deltafred · Post by **deltafred** » 06 Jan 2012, 09:46

bajaman wrote: the problem is that he has not connected the series connection of the two coils to ground
bajaman

This is next, thanks Bajaman.

slammer88 · Post by **slammer88** » 06 Jan 2012, 10:06

deltafred wrote:
bajaman wrote: the problem is that he has not connected the series connection of the two coils to ground
bajaman

Well, that didnt rsolve the humming, sadly

deltafred · Post by **deltafred** » 06 Jan 2012, 10:17

slammer88 wrote:I've measured the resistance as you told me..It shows ~250 ohms between output jack's outer shield and bridge. What now ?

250 ohms sounds too high, I like mine to be less than 5 at worst, less than 1 is better.

Try this

Get a piece of connecting wire, strip about 1.5" (40mm) of one end and wrap it wound the metal body of the jack plug.

Strip enough of the other end to hook it over or wrap it round the strings or something on the bridge.

See if it still buzzes when you take your hands off the strings.

slammer88 · Post by **slammer88** » 06 Jan 2012, 10:53

deltafred wrote:
slammer88 wrote:I've measured the resistance as you told me..It shows ~250 ohms between output jack's outer shield and bridge. What now ?
250 ohms sounds too high, I like mine to be less than 5 at worst, less than 1 is better.

Try this

Get a piece of connecting wire, strip about 1.5" (40mm) of one end and wrap it wound the metal body of the jack plug.

Strip enough of the other end to hook it over or wrap it round the strings or something on the bridge.

See if it still buzzes when you take your hands off the strings.

Well it still does :/ Actually i'm having this issue for a long time, ever since i've begun to play guitar. Once i didnt have this humming, when i was using EMG-81

We are running our electrical devices at 220V in Turkey btw, could it be the reason?

slammer88 · Post by **slammer88** » 06 Jan 2012, 11:51

https://www.diystompboxes.com/smfforum/ ... ic=94138.0

got the similar problem with this guy ^^

"but there will always be a difference "hands up" vs. "hands down" when the bridge is grounded." is that true? if yes, how is this elimininated in EMG's ?

deltafred · Post by **deltafred** » 06 Jan 2012, 12:23

slammer88 wrote:Well it still does :/ Actually i'm having this issue for a long time, ever since i've begun to play guitar. Once i didnt have this humming, when i was using EMG-81

We are running our electrical devices at 220V in Turkey btw, could it be the reason?

The mains voltage is pretty much irrelevant, In the UK it is 240v and as long as there is a good earth then everything is quiet.

It is looking like a mains earth fault but you are on your own with that, my mains wiring knowledge is limited to what we have in the UK.

I see now why you want to use the EMG Active circuit if that was the only time that the humming was not there.

slammer88 · Post by **slammer88** » 06 Jan 2012, 13:24

deltafred wrote:
slammer88 wrote:Well it still does :/ Actually i'm having this issue for a long time, ever since i've begun to play guitar. Once i didnt have this humming, when i was using EMG-81

We are running our electrical devices at 220V in Turkey btw, could it be the reason?
The mains voltage is pretty much irrelevant, In the UK it is 240v and as long as there is a good earth then everything is quiet.

It is looking like a mains earth fault but you are on your own with that, my mains wiring knowledge is limited to what we have in the UK.

I see now why you want to use the EMG Active circuit if that was the only time that the humming was not there.

Exactly what you've told

I was so happy with the EMG's on my old guitar, but i've upgraded into a 7 String and sold it. For Active EMG's my guitar needs to be routed a little, which i don't want, so i've gotten a passive pup, better than stock one, and thanks to Bajaman, i've made this little circuit, which is great

Thanks for the answers anyway, i appriciate you all

CHEEZOR · Post by **CHEEZOR** » 07 Jan 2012, 01:07

slammer88 wrote:https://www.diystompboxes.com/smfforum/ ... ic=94138.0

got the similar problem with this guy ^^

"but there will always be a difference "hands up" vs. "hands down" when the bridge is grounded." is that true? if yes, how is this elimininated in EMG's ?

This is eliminated in EMG's because the bridge / strings are not grounded. Therefore, you will hear no difference between when your hands are touching the strings and when your hands aren't on the strings because they are not a part of the circuit. They are also extremely quite pickups so there isn't much noise either.

skylark44 · Post by **skylark44** » 07 Jan 2012, 06:54

CHEEZOR wrote:
slammer88 wrote:https://www.diystompboxes.com/smfforum/ ... ic=94138.0

got the similar problem with this guy ^^

"but there will always be a difference "hands up" vs. "hands down" when the bridge is grounded." is that true? if yes, how is this elimininated in EMG's ?
This is eliminated in EMG's because the bridge / strings are not grounded. Therefore, you will hear no difference between when your hands are touching the strings and when your hands aren't on the strings because they are not a part of the circuit. They are also extremely quite pickups so there isn't much noise either.

+1