wiring a Lexicon100

dlayne · Post by **dlayne** » 12 Jun 2004 4:36 am

I hope some one can tell me how to wire up a stewart power amp,a Lexicon 100 and an Evans pre amp.My rack is not as noise less as it should be.....Thanks

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Dan Layne
videohorn@hotmail.com

Hal Higgins · Post by **Hal Higgins** » 12 Jun 2004 5:11 am

Dan....This is how I have mine wired...Starting with the Evans Preamp...two cables from the A & B outs to the Inputs of your power amp. Next from the sends (outs) of the preamp to the returns of the 100, then from the returns of the preamp to the sends of the 100. To further eliminate noise (hum)....get ground lift plugs (those litle three prong adapters) and put on all of your three prong electric cords. That should do ya.......HAL

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Be Blessed........HAL
'85 Emmons LeGrande D-10,(8 & 6) Hilton Vol. Pedal, BJS Birthstone bar, Rack w/Evans Pre-amp, Lexicon MPX500; (2)1501-4 BW's in custom built cabs by T.A. Gibson, & a Sound Tech 802 Digital Power Amp.

dlayne · Post by **dlayne** » 12 Jun 2004 5:17 am

Thanks Hal,giving it a try right now,I'll let you know how works,but you already know

....Thanks.

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Dan Layne
videohorn@hotmail.com

Hal Higgins · Post by **Hal Higgins** » 12 Jun 2004 7:33 am

No Problem.....glad I could help....be blessed

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Be Blessed........HAL
'85 Emmons LeGrande D-10,(8 & 6) Hilton Vol. Pedal, BJS Birthstone bar, Rack w/Evans Pre-amp, Lexicon MPX500; (2)1501-4 BW's in custom built cabs by T.A. Gibson, & a Sound Tech 802 Digital Power Amp.

Lee Baucum · Post by **Lee Baucum** » 12 Jun 2004 1:51 pm

<SMALL>To further eliminate noise (hum)....get ground lift plugs (those litle three prong adapters) and put on all of your three prong electric cords. That should do ya.......HAL</SMALL>

Please, please, please don't lift the ground on all of the electric cords. That could be fatal. Be sure to leave one of the devices grounded, lest you become the ground.

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Lee, from South Texas
Down On The Rio Grande

Hal Higgins · Post by **Hal Higgins** » 12 Jun 2004 11:04 pm

Lee....if using a rack system, you ground your whole rack unit when you plug it into the wall (or whatever)thusly each of the individual components can be ground lifted without any problem with anyone becoming he ground.........

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Be Blessed........HAL
'85 Emmons LeGrande D-10,(8 & 6) Hilton Vol. Pedal, BJS Birthstone bar, Rack w/Evans Pre-amp, Lexicon MPX500; (2)1501-4 BW's in custom built cabs by T.A. Gibson, & a Sound Tech 802 Digital Power Amp.

Lee Baucum · Post by **Lee Baucum** » 13 Jun 2004 12:43 pm

Hal - If there is an electrical problem with the power amp and none of the components have the third grounding prong connected to "ground", how is the user going to be protected? I was always told that at least one of the components should be grounded.

This is kinda drifting off-topic, so I'll start a new one.

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Lee, from South Texas
Down On The Rio Grande

Hal Higgins · Post by **Hal Higgins** » 13 Jun 2004 1:47 pm

Lee....if the rack system is grounded through the receptical....then the individual components do not have to be re-grounded.....it's the double ground that causes the hum.

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Be Blessed........HAL
'85 Emmons LeGrande D-10,(8 & 6) Hilton Vol. Pedal, BJS Birthstone bar, Rack w/Evans Pre-amp, Lexicon MPX500; (2)1501-4 BW's in custom built cabs by T.A. Gibson, & a Sound Tech 802 Digital Power Amp.

Jim Smith · Post by **Jim Smith** » 13 Jun 2004 7:05 pm

The only way for a rack system to be "grounded through the receptical" is to have at least one unit grounded via the three prong plug. Ideally it should be just one unit to prevent ground loops, but at least one unit MUST have the ground plug intact. Even if you plug the rack units into a grounding power strip which plugs into the wall, one of those rack units MUST have the ground plug in order to transfer the ground from the wall to the rack.

Hal Higgins · Post by **Hal Higgins** » 13 Jun 2004 8:40 pm

The way I have my rack unit wired up is from the inside I have my receptacle (three wire male)...from that I use a short three wire extension to the Steelers Choice Seat that has a power strip built in that goes to the wall receptacle......thusly, I'm grounded, that's why I say I can ground lift all units within the rack......I've done it and it eliminates the ground loop(s). All the units are plugged in inside the rack into a power strip that has been wired in directly to the three prong male.

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Be Blessed........HAL
'85 Emmons LeGrande D-10,(8 & 6) Hilton Vol. Pedal, BJS Birthstone bar, Rack w/Evans Pre-amp, Lexicon MPX500; (2)1501-4 BW's in custom built cabs by T.A. Gibson, & a Sound Tech 802 Digital Power Amp.

Jim Smith · Post by **Jim Smith** » 14 Jun 2004 5:08 am

Hal, the power strip in your seat is grounded, and the one in your rack is grounded, because they both use the three wire power cords. However, unless at least one of the units in your rack case is plugged in with a three wire power cord, your rack is NOT grounded.

The only reason you don't have a ground loop is because you have no ground to loop!

This is potentially (pun intended) a very serious issue and should be remedied immediately!

Lee Baucum · Post by **Lee Baucum** » 14 Jun 2004 5:13 am

Thanks, Jim. You beat me to the punch.

My little rack just has two units in it. One is for reverb and one for delay. Both of them have "wall warts", which are only two prong.

But, I would bet that any rack mountable power amp is going to have a three prong plug on it. If the ground is lifted on that unit and all the other three prong units in the rack, the components are not grounded.

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Lee, from South Texas
Down On The Rio Grande

Jim Smith · Post by **Jim Smith** » 14 Jun 2004 5:25 am

Good point Lee. If there are no three prong plugs in your rack, you should find a power strip that has a separate ground post and run a separate wire to the chassis of one of the units. I haven't seen one of those strips for a long time though, so I'm not sure if they are still made.

Hal Higgins · Post by **Hal Higgins** » 14 Jun 2004 5:43 am

Jim & Lee......Before placing the three prong adapters (the ground lift plugs) in the line(s), I was getting hum galore, as soon as I put them inline, all of the humming stopped, now I'm as quiet as a mouse. Go figure! So, am I grounded or not?

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Be Blessed........HAL
'85 Emmons LeGrande D-10,(8 & 6) Hilton Vol. Pedal, BJS Birthstone bar, Rack w/Evans Pre-amp, Lexicon MPX500; (2)1501-4 BW's in custom built cabs by T.A. Gibson, & a Sound Tech 802 Digital Power Amp.

Jim Smith · Post by **Jim Smith** » 14 Jun 2004 6:19 am

Again, no you're not grounded. Remove one of the ground lift adapters from one of the units inside your rack case. Now you'll have one unit that is grounded and the others will get their ground from it. You should have no hum that way, and if you do, there is some other problem in your rig.

Tony Dingus · Post by **Tony Dingus** » 14 Jun 2004 6:48 pm

I read in the Ozark steel newsletter sometime back about a hum problem where the Evans pre amp and the Lexicon 100 were next to each other in the rack and when they moved them away from each other the hum was gone. If what has already been said didn't work, and you have them close to each other, separate them and see it that helps.
Tony

Jim Smith · Post by **Jim Smith** » 14 Jun 2004 7:08 pm

In case you missed it, you should read this current (again pun intended) thread:
http://steelguitarforum.com/Forum11/HTML/005446.html

dlayne · Post by **dlayne** » 15 Jun 2004 5:34 am

Tony,I seperated the Evans and Lexicon and you are right on about the hum leaving,Thanks Tony and every one else.

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Dan Layne
videohorn@hotmail.com