ADA Depot - A Forum To Support Users of ADA Amplification Gear

Let's Get Technical => Troubleshooting Problems => Topic started by: Georgeclooney0 on November 26, 2018, 07:40:07 PM

Title: Rack grounding?
Post by: Georgeclooney0 on November 26, 2018, 07:40:07 PM
Hi all, first post here. I originally signed up to talk about the awesome mp1 but then this came up. I am building my first rack, I have so far the mp1, jmp 1, alesis 3630 compressor, an old digitech dhp-55, and a furman power strip. I mounted everything in the rack using rubber washers, plugged the units into the furman, routed everything, fired it up and have been jamming ever since. My question is am I good to go as far as grounding the units. I have since read a bit and grounding seams to be a concern for a lot of people. As far as I know I thought all the units would be grounded through the 120 VAC outlets on the furman. My question is, is my setup sufficient like I have it currently. I don't want to damage anything. Also I apologize in advance if I posted this in the wrong place, it wasn't obvious to me where I should go with this.
Title: Re: Rack grounding?
Post by: Dante on November 27, 2018, 08:08:32 PM
Welcome to the Depot, George!

I'm sure the rubber washers will work, but I'll let others voice their opinions too. I have heard of several others (myself included) just putting a couple layers of electrical tape on the rails before mounting the rack gear. I do believe I have nothing grounding my current rack, I was in a hurry to put it together and didn't bother with dang ol' tape.

in hindsight, I created a lot more work for myself if I notice a problem  :facepalm:
Title: Re: Rack grounding?
Post by: rnolan on November 27, 2018, 09:58:55 PM
Hey Gc0, welcome to the depot  :thumb-up: :wave: , this is probably as good a place as any for your post.  Depending on your setup you can sometimes get earth loops as the units contact the metal rack strip. rabidgerry had some issues a while ago and went through the process of isolating the units from the rack strip so they didn't earth to each other via touching the strip or touching each other, but he had earth hums he needed to eliminate and had also done some research on the issue (http://adadepot.com/index.php?topic=2198.msg25165#msg25165).If you have no hum, noise etc then you don't need to isolate the units, I've never had any issues. I use plastic washers to protect the unit(s) from screw rash but they all touch/contact the metal rack strip.  I try to make the distance between units as far apart as is easy (slight gap), but this is for heat dissipation/airflow not to stop them touching.So if you have no earth hums etc then your setup is sufficient and you wont damage anything  :thumb-up: .
Title: Re: Rack grounding?
Post by: rabidgerry on November 28, 2018, 06:16:17 AM
I touched on this topic in my "Rack Developement"  thread in "Rack Gear"

I referenced this website also.

https://aperioguitar.com/2012/02/23/grounding-fizz-and-cable/ (https://aperioguitar.com/2012/02/23/grounding-fizz-and-cable/)

I grounded some of my items and I thought initially I had gotten rid of a weird hum but I detected the weird hum in different venues so not sure if I actually got rid of the problem or not by grounding the items.  Also a few things I probably could do with adding a few little "rubber feet" to seperate their chassis from one another.  I also did the tape on the rack ears.
Title: Re: Rack grounding?
Post by: Dante on November 28, 2018, 07:38:01 AM
That reminds me.... I was getting noise that I thought was a bad ground, but it was the cheap universal wall-wart power units I was using. From now on, I buy better power suppliers like a One-Spot on my pedal board.
Title: Re: Rack grounding?
Post by: rabidgerry on November 28, 2018, 08:03:36 AM
Only walwarts I'm using are official Boss units.

I have heard cheaper ones or damaged ones making noise before.
Title: Re: Rack grounding?
Post by: Georgeclooney0 on November 28, 2018, 05:02:44 PM
Thanks for the replies guys. I slapped myself on the forehead a couple of times as soon as I started reading. I didnt even think about the units touching each other via the rack.  I guess it's not a problem until it is. I'm sure if a fault was coming inside one of the units this could def become an issue. Well that's good to know. Speaking of noise.... I was running some pedals off of a cheap surge protector and had a good bit of noise from the mp-1. That was when I first got it and I thought it was just noisy. I have it racked now with no pedals and everything plugged into the furman. The thing is really quiet now, at least at low volumes, haven't had a chance to crank it!
Title: Re: Rack grounding?
Post by: Georgeclooney0 on November 28, 2018, 05:12:06 PM
On second thoughts I now have a noise gate in between the guitar and the mp-1. I think that may be what's doing the trick, I just opened it up and the noise is back.
Title: Re: Rack grounding?
Post by: rabidgerry on November 29, 2018, 02:58:34 AM
You shouldn't need a noise gate between guitar and MP1, that's a bit unusual to have one there (to me anyway).  If this has cleared up the noise then this would imply that there is noise before the MP1 and then what is happening is the MP1 is amplifying that noise and making it worse.

Mind you you are using a compressor before it, so that may be causing excess noise, but then a noise gate after the mp1 should clear that up anyways.
Title: Re: Rack grounding?
Post by: Soloist on November 29, 2018, 06:18:32 AM
Having the noise gate between the guitar and Mp1 taking out the noise would imply that you are getting noise from the guitar pick ups. I run a gate before my mp1 as well because I put all my od's in the gates loop.
Title: Re: Rack grounding?
Post by: rabidgerry on November 29, 2018, 07:10:51 AM
Or his compressor which he might be running into first.

George are you going in first to the compressor?

Technically my noise gate is first in the chain, but more technically the noise gate is tracking the guitar signal and not doing anything with it other than using it for reference and the actual gate function does it's thing AFTER the MP1/Preamp of my choice.  So like soloist I am using the loop of my noise gate and I place my distortion generating devices (in my case a preamp) within this loop.  So the gate can close behind them when I stop playing.
Title: Re: Rack grounding?
Post by: Georgeclooney0 on November 29, 2018, 09:12:09 AM
That's right, I have the guitar plugged straight into the alesis compressor, pumpkins style and then out to everything else. The compressor has a gate on it which is the only reason I found this. I would have not thought to put one there myself.
Title: Re: Rack grounding?
Post by: MarshallJMP on November 29, 2018, 09:33:29 AM
I'm also using a gate (decimator pro G) before and after the mp-1, this works better and faster and you don't get those nasty chatter sounds.
Title: Re: Rack grounding?
Post by: rabidgerry on November 29, 2018, 10:24:42 AM
I'm also using a gate (decimator pro G) before and after the mp-1, this works better and faster and you don't get those nasty chatter sounds.

But the actual gating is done after the MP1 right MJMP?  Just so George is clear on what we mean when we say we have the gate first.

It's not actually gating before the MP1 it's gating after correct?  I had a decimator G-string once and it had a loop which obviously went first (again only to reference the original guitar sound) and then the distortion gear went in the loop and the actual gating in the chain was done after the item in the loop.

I'm only being specific as it can sound like we have two separate gates the way we talk about it, like we have a gate to clean up the guitar before going into the distortion device.  Which is also another thing some people do (not me).
Title: Re: Rack grounding?
Post by: MarshallJMP on November 29, 2018, 11:22:06 AM
No the decimator has 2 gates and one is used before and one after the mp-1. So I'm gating before and after. This works great and makes it less sensitive to chatter, it also reacts faster for opening and closing. ISP even suggests you use it that way.
Title: Re: Rack grounding?
Post by: Soloist on November 29, 2018, 11:37:36 AM
If you are using an Alesis 3630 comp. That's your issue.  They are notorious for being noisey.
That's why I sold mine years ago. The gate on it is awful  :facepalm:
Title: Re: Rack grounding?
Post by: rabidgerry on November 29, 2018, 12:03:40 PM
If you are using an Alesis 3630 comp. That's your issue.  They are notorious for being noisey.
That's why I sold mine years ago. The gate on it is awful  :facepalm:

I'm not surprised

No the decimator has 2 gates and one is used before and one after the mp-1. So I'm gating before and after. This works great and makes it less sensitive to chatter, it also reacts faster for opening and closing. ISP even suggests you use it that way.

Who get's chatter unless they stick a noise gate after delay  :lol:

Ahh right, I see, I didn't realise it had two gates.  So you are one of those who gate twice then.  I personally have never ever needed this.  Would you always used used two gates before the Decimator?  Do you get a lot of noise with your setup that you need them both?

So with the two gates, is the first one for noise you have coming from other pedals BEFORE the MP1?  I didn't realise you had anything noisey before the MP1
Title: Re: Rack grounding?
Post by: MarshallJMP on November 30, 2018, 03:58:17 AM
Well my first gate was a boss NF-1 (the old one, still have it ), then I upgraded to the NS-2 (which I also still have in my pedal board) but I wanted something in a rack so the next one was the alessis 3630, it worked okay (also used in before/after) but it wasn't fast enough for my taste and then came the ISP which was the best gate I ever used.

Do I have a lot of noise before my MP-1, well not really (I only have the dunlop rack wah in front of my MP-1) but PU's always pickup noise which get's amplified a lot in distortion pedals/ racks so it helps. But the most important fact is that it just works better this way. Hard to describe. But I searched for years to find a gate that worked for my taste.

Try to hook up your guitar to the mp-1, no gates, and turn on and off the guitar volume, you will hear an increase in noise when the guitar volume is all the way up.
Title: Re: Rack grounding?
Post by: rabidgerry on November 30, 2018, 08:44:39 AM
Do I have a lot of noise before my MP-1, well not really (I only have the dunlop rack wah in front of my MP-1) but PU's always pickup noise which get's amplified a lot in distortion pedals/ racks so it helps. But the most important fact is that it just works better this way. Hard to describe. But I searched for years to find a gate that worked for my taste.

Yup, but when I set the threshold on my noise gate (as per the operation manual)  I set the threshold until the noise I don't want to hear disappears.  Isn't that the normal way?  So if I set one gate to get rid of noise I have no idea what to set the other one two as the noise is already gone.

If you don't have a lot of noise before you'r MP1 i don't really see why you (perhaps others may need it) would require the first noise gate?  Do you just use it because it's there?

It's got me thinking now perhaps two is the way to go?  As you know I play loud and with a lot of gain.  But in all honestly since I stopped relying on inbuilt MFX noise reduction my feedback issues that I used to have are gone (still like to get a bit of feedback for dramatic effect when I take hands of the string haha) since I started using the half rack NS-50.

If for example you wanted, could you run two seperate noise gate pedals that were single ended?  And place them before distortion and after distortion and that would work better than say a noise gate that has a tracking loop and then the gate that goes after the distortion?
Title: Re: Rack grounding?
Post by: MarshallJMP on November 30, 2018, 01:40:32 PM
Well I don't use "the until the noise disappears" method, I just play with the 2 threshold until it feels right. But even with 2 gates you can use that method if you like, you first start with the first gate and change the threshold until it cuts off the guitar noise and then set the 2nd one for the rest of the noise.

Also I use a gate for 2 things, one is noise and more important to me feedback and I set it so I have no noise and no feedback.
Title: Re: Rack grounding?
Post by: Soloist on December 01, 2018, 01:05:24 PM
MJMP, how do you have your fx loop set on the MP1 with that configuration? Is it just set to 0db? I was thinking of running my NS2 in that 4 cable method.
Title: Re: Rack grounding?
Post by: MarshallJMP on December 01, 2018, 01:31:56 PM
Don't use the loop, the out A goes to the decimator.
Title: Re: Rack grounding?
Post by: rabidgerry on December 02, 2018, 06:12:24 AM
I don't get any noise from my guitar.perhaps I don't need to bother with this.
I get noise from single coils just with distortion. It also depends where I am, some venues just have awful wiring.
Title: Re: Rack grounding?
Post by: MarshallJMP on December 03, 2018, 09:05:19 AM
All pu's pick up noise, it just depends what's "floating" in the air. Just go stand next to your amps transformer, it will pick up it's magnetic field. Usually with clean sounds you will not hear noise but with  distortion you will.
Title: Re: Rack grounding?
Post by: rabidgerry on December 03, 2018, 11:30:13 AM
All pu's pick up noise, it just depends what's "floating" in the air. Just go stand next to your amps transformer, it will pick up it's magnetic field. Usually with clean sounds you will not hear noise but with  distortion you will.

Yes I agree that pickups make noise, but you surely know what I am getting at here?  My pickups don't make anymore noise by themselves that I would require a second gate before distortion.  This to me implies you get noise loud enough to be heard before going into a distortion unit.  Where as I am saying I don't have this issue.

I turn the distortion off and the majority of noise is gone with a properly shielded guitar of course.

For me both live and in studio you can only hear noise it when the distortion or compressor is amplifying it and then that's why there is a noise gate after that device to cut that out.

About standing next to an amp, this isn't a normal thing to do in my opinion, not when performing anyways, and if I am close enough to get noise, I take one step away and the noise is gone with a single noise gate switched on.  I can actually adjust things if I need to at arms length without getting all that hum.  I don't usually need to but if I do at gigs I never hear it.  In our practice room, I might get it when I'm like 6-12" away, but again that wont be where I am standing to play songs so it's not an issue.

Title: Re: Rack grounding?
Post by: Soloist on December 03, 2018, 02:25:54 PM
Ok, so I hooked up my NS2 like MJMP has his pro G wired and the boss does not cut it that way. Totally smothers the tone. Oh well,  the way I have it routed seems to be the best option I have at the moment. It was worth a shot, you never know!
Title: Re: Rack grounding?
Post by: MarshallJMP on December 03, 2018, 02:51:25 PM
@Gerry, I don't have much noise from the PU's but that's not so important, it just works a lot better with 2 gates, I guess it's hard to explain  ;D ,you need to try it and feel it, play it. I messed around with different gates for years until I finally found what I was looking for.

Years ago when I had the NS-2 I wired it up like that and it worked but yes it took away some tone.
Title: Re: Rack grounding?
Post by: rabidgerry on December 04, 2018, 04:46:05 AM
I'm totally fine using the NS-50 which is a bit like an NS2.

I have the threshold around 45-50% (about 11-12 o clock).  This is totally adequate I find.  No noise and feedback is under control.  I still have more to play with as well with the threshold should I ever need it.  I run into the NS-50, the guitar in, then the output comes out and runs into the FX unit input.
Like this:
 
                                                                                      FX Send > Preamp In > Preamp Out 
                                                                                    /                                                      \
 Guitar > ns50 Guitar IN > ns50 Guitar Out > FX Input >                                              ns50 Input
                                                                                                                                             /
                                                  Cabs < Power Amp < FX Output < FX Return < ns50 Output           
                                         
Title: Re: Rack grounding?
Post by: Soloist on December 04, 2018, 06:24:44 AM
Very similar Gerry. I run guitar> NS2 input. NS2 send> od's and eq pedals. Last pedal> NS2 return. NS2 output to amp input. Using the gate in my G Force after the preamp. Threshold on NS2 about 60% and the decay about 20%. All settings are very low on the g gforce gate. All quiet before it hits the front of the amp and all quiet after.
Title: Re: Rack grounding?
Post by: rabidgerry on December 04, 2018, 11:07:57 AM
There are a number of other ways to hook mine up but honestly, my tone isn't being affected that much by the NS-50, and on the threshold I'm way above the point where light playing will suffer with the chitter MJMP mentioned in this thread earlier.

The two gates thing I have a theory might be beneficial in regards to guitar resonance that can sometime keep your normal single gate open long enough to allow feedback, where as if you have a gate before distortion also it's going to snub that lagging resonance on the head before it gets a chance to develop into something nasty.  Just a theory.

Hey Soloist, yeah that is similar my man, my rack noise gate is like the rack version of the ns-2,  couldn't say if it was better, I do rate it highly though.  Since my GX700 has built in noise reduction I suppose I could stick that on lightly somewhere, perhaps before the loop where my preamp is.

I also have a hush IICX I guess I could in theory use this like two gates since that is what it is  :lol:  Go into channel 1 and have that cover before any distortion then use channel II like normal.  I really like this Hush unit.  It's from 1989 or something but sounds awesome in my opinion.