NOISE, NOISE, NOISE...

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
neuk01642
Posts: 24
Joined: Thu Sep 28, 2017 2:46 am

Re: NOISE, NOISE, NOISE...

Post by neuk01642 » Thu Sep 28, 2017 9:06 am

What are those ties like that called?
I've tried googling them but just get zip ties all the time.

M

neuk01642
Posts: 24
Joined: Thu Sep 28, 2017 2:46 am

Re: NOISE, NOISE, NOISE...

Post by neuk01642 » Thu Sep 28, 2017 9:18 am

Actually. No worries. Found them
Company called cable ties direct... that there is a niche business!

Wonder how munch of their repeat businesses is pedal board makers :D

JohnClark
Posts: 7121
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: NOISE, NOISE, NOISE...

Post by JohnClark » Thu Sep 28, 2017 9:42 am

Hello and welcome!

As a test, can you try plugging your guitar directly into the In of Loop 1?
The noise you have might just be due to a ground loop in the rig. If this does solve the main noise issue, you can lift the chassis ground inside the GCX or isolate the GCX chassis from the rack rails using a product known as HumFrees.

While not related to the noise issue, I would try to avoid running the Guitar In buffer in front of your fuzzes. Fuzz pedals often don't sound quite right with a buffer in front of them. Once we get the main noise eliminated you can test the difference of having the buffer there or not by using the rear panel Feedthru to connect to the In of Loop 1. Then by plugging your guitar into the Guitar In or the front panel Feedthru will be a sort of A/B between having or not having the buffer.

Let us know how it goes!

neuk01642
Posts: 24
Joined: Thu Sep 28, 2017 2:46 am

Re: NOISE, NOISE, NOISE...

Post by neuk01642 » Thu Sep 28, 2017 9:49 am

JohnClark wrote:Hello and welcome!

As a test, can you try plugging your guitar directly into the In of Loop 1?
The noise you have might just be due to a ground loop in the rig. If this does solve the main noise issue, you can lift the chassis ground inside the GCX or isolate the GCX chassis from the rack rails using a product known as HumFrees.

While not related to the noise issue, I would try to avoid running the Guitar In buffer in front of your fuzzes. Fuzz pedals often don't sound quite right with a buffer in front of them. Once we get the main noise eliminated you can test the difference of having the buffer there or not by using the rear panel Feedthru to connect to the In of Loop 1. Then by plugging your guitar into the Guitar In or the front panel Feedthru will be a sort of A/B between having or not having the buffer.

Let us know how it goes!
Nice one John, thank you.
Will look into the plugging into the loop and try that first and also the buffer issue hadn't occurred to me.
Do you know of anywhere in the UK that stocks Humfrees? might be worth the investment straight away anyway

JohnClark
Posts: 7121
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: NOISE, NOISE, NOISE...

Post by JohnClark » Thu Sep 28, 2017 9:50 am

I don't know for certain who carries them in the UK, sorry. I'm of the opinion that it is better to test that they are needed before just buying them and throwing them on everything anyway ;)

I should add that after eliminating the main noise, you could then really get to hearing the difference good cables afford too!

neuk01642
Posts: 24
Joined: Thu Sep 28, 2017 2:46 am

Re: NOISE, NOISE, NOISE...

Post by neuk01642 » Thu Sep 28, 2017 9:58 am

JohnClark wrote:Hello and welcome!

If this does solve the main noise issue, you can lift the chassis ground inside the GCX
John what does this mean and how do you do it?

Sounds scarily like I might need to know what I'm doing...

JohnClark
Posts: 7121
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: NOISE, NOISE, NOISE...

Post by JohnClark » Thu Sep 28, 2017 10:20 am

neuk01642 wrote:
JohnClark wrote:Hello and welcome!

If this does solve the main noise issue, you can lift the chassis ground inside the GCX
John what does this mean and how do you do it?

Sounds scarily like I might need to know what I'm doing...
It is quite easy really. If the test does show that the noise is actually a ground loop buzz then you will need to remove the GCX from the rack to open up the chassis. Inside the GCX, just behind the two front panel jacks, is a screw that holds one of the circuit boards in place. It also mounts a ground lug wire. Removing the screw and pulling the ground lug out of the way before replacing the screw will lift the audio ground from the GCX chassis.

neuk01642
Posts: 24
Joined: Thu Sep 28, 2017 2:46 am

Re: NOISE, NOISE, NOISE...

Post by neuk01642 » Thu Sep 28, 2017 12:22 pm

JohnClark wrote:
neuk01642 wrote:
JohnClark wrote:Hello and welcome!

It is quite easy really. If the test does show that the noise is actually a ground loop buzz then you will need to remove the GCX from the rack to open up the chassis. Inside the GCX, just behind the two front panel jacks, is a screw that holds one of the circuit boards in place. It also mounts a ground lug wire. Removing the screw and pulling the ground lug out of the way before replacing the screw will lift the audio ground from the GCX chassis.
John. Hats off sir, you called it. MASSIVE ground loop. Plugged direct into loop 1, silence.
So I'm ordering some of the humfrees and I'll disconnect the ground.

I'm guessing there's no risk in this? I'm not going to fry myself or blow up the house?

JohnClark
Posts: 7121
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: NOISE, NOISE, NOISE...

Post by JohnClark » Thu Sep 28, 2017 12:27 pm

neuk01642 wrote:I'm guessing there's no risk in this? I'm not going to fry myself or blow up the house?

No harm lifting the audio ground at all! But I should point out that the fix is lifting the chassis ground OR using HumFrees. You certainly don't need to do both.

bettsaj
Posts: 210
Joined: Fri Jun 11, 2010 12:13 pm
Location: Darkest Suffolk UK
Contact:

Re: NOISE, NOISE, NOISE...

Post by bettsaj » Fri Sep 29, 2017 12:20 am

neuk01642 wrote:
JohnClark wrote:Hello and welcome!

As a test, can you try plugging your guitar directly into the In of Loop 1?
The noise you have might just be due to a ground loop in the rig. If this does solve the main noise issue, you can lift the chassis ground inside the GCX or isolate the GCX chassis from the rack rails using a product known as HumFrees.

While not related to the noise issue, I would try to avoid running the Guitar In buffer in front of your fuzzes. Fuzz pedals often don't sound quite right with a buffer in front of them. Once we get the main noise eliminated you can test the difference of having the buffer there or not by using the rear panel Feedthru to connect to the In of Loop 1. Then by plugging your guitar into the Guitar In or the front panel Feedthru will be a sort of A/B between having or not having the buffer.

Let us know how it goes!
Nice one John, thank you.
Will look into the plugging into the loop and try that first and also the buffer issue hadn't occurred to me.
Do you know of anywhere in the UK that stocks Humfrees? might be worth the investment straight away anyway
Thomann do them, they are expensive, for what they are. I used plastic washers and electrical insulating tape :lol:

You can buy the HumFrees here

https://www.thomann.de/gb/adam_hall_hum ... arch_prv_3
"My technique is laughable at times. I have developed a style of my own, I suppose, which creeps around. I'll never be a very fast guitar player."

David Gilmour

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