Overwhelming ground hum without humbusters

alexwald

alexwald

Member
I've tried my FX8 with a real amp in the rehearsal room for the first time yesterday with regular cables (no humbuster yet) in 4CM and the amount ground hum rendered the unit unusable.

I've also tried only going direct in front of the amp (guitar>cable>fx8>cable>amp input), with the same result.

I've also tried the other guitarists peavey 6505, same problem.

what am I doing wrong? is FX8 really unsuable without humbuster?
 
You can covert your cables to humbusters pretty easily. Just buy some trs jacks and solder then to one end per the fx8 manual
 
Tahoebrian5 said:
You can covert your cables to humbusters pretty easily. Just buy some trs jacks and solder then to one end per the fx8 manual
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The cable itself needs 3 leads versus the 2 in a regular mono TS guitar cable. A 3-wire cable with TRS ends can be converted to Humbuster by adding a TS plug on one end and soldering ring to sleeve on the TS end.
 
I know, but does this mean that fx8 is practically unusable without humbuster?


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Whenever you have ANY rig that have effects in the front of the amp and in the fX loop of the amp or A/C powered effects into the front of the amp you are usually going to have ground loops. Guys like Dave Friedman(who I worked for for 3 years) and Bob Bradshaw are kept very busy eliminating ground loops in pro rigs. It's a fact of life. High gain rigs enhance ground loop noise even more. There can be many steps to eliminate ground loops. First thing I would do is make sure that the FX8 is plugged into the same circuit as your amp. You will probably still have ground noise but that first step is important. Humbuster technology is an easy and very inexpensive solution to your issue. You could potentially spend thousands of dollars having a Rig Builder make you a quiet rig.
Like someone else suggested, you can make your own Humbuster cables if you want. Fractal has provided Humbuster technology into the FX8 to solve most ground loop noise issues.

I'm positive if you had a few pedals in front of your amp and say a delay pedal in the loop of your amp you will get a ground loop as well, this is just something that happens with rigs.

Something very important to understand is that some folks get rid of ground noise by using cheater ac plugs or cutting ground prongs from ac cords. DO NOT DO THIS. It is very dangerous and you can be electrocuted and killed or severely injured.

Mark
 
Definitely make sure the the FX8 and your amp are plugged in on the same circuit. I have the humbuster cables but not using them. My regular cables are fine. No ground loop hum issues but I'm going to switch them out just to be on the safe side when I start gigging the unit. I have the normal high gain amp hiss but that is addressed with the noise gate. FYI I'm using it with an EVH 5153 100 watt.
 
I'll double check about amp and FX8 being on the same circuit tomorrow, but I'm pretty sure they were last time I checked. Meanwhile, I've made my own humbuster cables, we'll see if that makes any difference.
just FYI, the ground hum noise (when I muted the strings) was as loud as the hi-gain channel itself when playing, full on.

I've tried connecting guitar > regular cable > FX8 in front > regular cable > amp input
with no connection to amps Fx loop, the ground hum noise was still as lound as the hi-gain channel itself.

the other guitar player also has AC-powered unit in front (line6 m9 I believe) + about 3 additional pedals, with no ground hum problems.
 
alexwald said:
I'll double check about amp and FX8 being on the same circuit tomorrow, but I'm pretty sure they were last time I checked. Meanwhile, I've made my own humbuster cables, we'll see if that makes any difference.
just FYI, the ground hum noise (when I muted the strings) was as loud as the hi-gain channel itself when playing, full on.

I've tried connecting guitar > regular cable > FX8 in front > regular cable > amp input
with no connection to amps Fx loop, the ground hum noise was still as lound as the hi-gain channel itself.

the other guitar player also has AC-powered unit in front (line6 m9 I believe) + about 3 additional pedals, with no ground hum problems.
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The M9 is not AC-powered. It uses a DC adapter. Any product with an internal power supply requires a connection from the chassis to safety ground. This can cause ground loops. The tips above will help you remedy this.
 
Lair Williams at the TC Electronics forum wrote the "White Papers." https://www.google.com/url?sa=t&rct...ZK0B4kYFHciJKeA&bvm=bv.99804247,d.eXY&cad=rja
This is aimed at the G-System but there are some incredible tips on troubleshooting ground loops, noise, hum, etc.. It's definitely a worthwhile read. The parts about noise anyway.

Another thing to consider is that the problem might be in the rehearsal space's wiring.
I had a very slight hum practicing at my house with the band a few years ago. It was very manageable. Then, we played a gig at a local dive bar and the hum was so bad that the gig was a total nightmare. When I would stop playing, with the guitar turned up, it basically sounded like I cranked my amp and left a cord plugged into the front of the amp with no guitar attached.
Long story short, I thought it was the wiring in the bar. They had several neon and fluorescent lights on the stage. The plugs were broken and hanging out of the covers......just really a dumpy place.
I tried my setup again at my house the next day and the hum was there. I was able to troubleshoot it and found that the shielding paint in my Ibanez JS1000 was starting to fail. An hour and some copper foil later, and my setup was dead silent again.


I've only used the FX8 with my Rivera Fandango so far. The Fandango has given me hum issues with almost every pedal switcher, the G-System, H9, HD500X, you name it, the Fandango didn't like them.
It is dead silent with the FX8.
I can't wait to try it with my little Archon 25!

I guess my point is, that there are many factors in the entire setup that can affect noise, hum, whatever. Sometimes the situation is just right for dead silent setups, other times it just takes a bit of research and tenacity to figure out what's wrong.
It's always a good idea to try the entire setup in a different room or on a different circuit than the one that hums.
Also, good to try different cords.
Hope this helps and it's not just the ramblings of a man who needs lunch......
 
I used the FX8 with 4cm with my HK Tubemeister 36 in a couple of clubs and never a ground loop. It just worked. So, there's something being added to your rig that's causing the loop.
 
DavidE said:
I used the FX8 with 4cm with my HK Tubemeister 36 in a couple of clubs and never a ground loop. It just worked. So, there's something being added to your rig that's causing the loop.
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I think a lot of it is determined by the amp.
My other rig is a Digitech GSP1101. It's an incredible piece of equipment with the MustBeBeta software, not so great without it.
I use the GSP with a Rivera S120 stereo tube combo from 1990. That amp has hated every pedal and processor that I have thrown at it, with the exception of the GSP and a G-Major 2. It absolutely despised the G-System that I used to have. It gets along with the GSP1101 very well though.
Sometimes it's just a matter of finding gear that goes together. The only amp that I have had zero problems with ground loops is a Roadking Series 1 that I used to have. It loved everything, but the cleans were terrible and it weighed 108 pounds.

If you are scientific about your setup, you can easily isolate the ground loop, if it is a ground loop.

Between each step, place the amp on Standby so that you don't have any unnecessary pops.

1. Plug your guitar into your amp with nothing else connected to it.
If no hum, move to the next step.

2. Next, plug the FX8 Out into the Return of the amp.
Turn the Standby off and see if you have any hum.
If not, next step.

3. Plug the Amp Send to the FX8 In (Post)
Turn the amp on and see if there is hum.
Play your guitar for a little while.
If no hum, move on.

4. Plug a cable from the FX8 Out (Pre) to the amp's input.
Do not plug your guitar into the FX8 yet.
Turn the amp on and see if there is hum.
If no hum, next step......

5. Plug your guitar into the FX8 Input.
Turn the amp on and play.


These steps will help you isolate where the hum is coming from. It is usually only 1 or 2 connections that are doing it.
The chances of a ground loop can be greatly exaggerated if you are using the Relays to control the amp's switching functions because it is another cord (or 2) that connect the same two devices.
Midi is great because there are opto-isolators in the midi circuit, so the amp and the FX8 are physically disconnected from each other on these cables.

Once you have isolated where the hum comes from, then you can try different cables, isolation transformers, humbuster cables, etc..
 
Can you post a clip of the noise you're hearing. People often use words like "hum," "interference" and "hiss" as if they were the same thing. But they're very different things, with different fixes.
 
I have used my FX8 with four of my amps without humbuster cables and have had no issues. I'm going stright through the front end. No 4CM.
 
Jalevinemd said:
I have used my FX8 with four of my amps without humbuster cables and have had no issues. I'm going stright through the front end. No 4CM.
Click to expand...

I think the 4CM adds a lot more potential for ground loops though because you have many more connections between the same two pieces of gear.
 
FractalAudio said:
...Any product with an internal power supply requires a connection from the chassis to safety ground. This can cause ground loops. The tips above will help you remedy this.
Click to expand...

ok, with humbusters the hum is now completely gone; this was the most informative and explaining comment for me
 
Right on!
What amp are you using? This way the next guy with that amp will know that he should order the cables at the same time.
 
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