Effect Gizmo Noise

D

Dani

Member
Hi,
Just got myself an Effect Gizmo and worked great so far but it causes some noise and I cant identify where it comes from.
I took it out of my Rack for testing reasons, nothing conntected, all loops are empty, just guitar in the front input and then going out at the back from the buffer out to the amp.
Adds some noise to it, when I go straight into the amp (also with both cables, connected through a true bypass box) the noise is gone, so its not the cables I think. When I bypass the buffer, connecting "from front" with "1-4 Input" and then going from the "output 1-4" to the amp its the same noise (when the guitar is turned down) but then when I turn up the guitars volume there is even more noise, almost impossible to play! Ground Lift switch didnt help unfortunately.
Any Ideas? Setup is still the same, nothing conntected, just the guitar going in the EG and then straight into the amp, so I can test everything you want. I´m a little lost at the moment with this problem ...
Greetings Daniel
(and sorry for my bad english I do my best^^)
 
1)Try some other cables just in case it is the cables

2) could possibly a ground loop issue from the effect gizmo to the amp. May be worth making a ground lift cable to try it. remove the braided outer sleeve from one of the jack pugs on the cable from the EG gizmo to the amp.

3) what power supply are you using to power the effect gizmo ac/dc and whats its voltage and current rating

Im sure Ron will be along at some point with more suggestions
 
The second case is easier to address than the first. By bypassing the buffer, there's no connection between the audio ground and the chassis. This would cause lots of buzz due to the floating ground.

Try this: connect a cable from the buffer output to the return of loop 1. Don't turn the loop on. Keep the ground lift switch in the out "not lifted" position. This will add a connection to ground while still keeping the buffer out of the signal path. The noise should no worse than your experiment with the buffer, and it might be better. If the "no buffer" case is quieter than with the buffer, there may be a problem with your buffer.

Give it a try and let us know what you find!
 
Thanks for your quick answers, great support!
Thought I might try the easiest Solution first, changed the Power Supply from 12VDC to 9VAC and the noise is completely gone! Never thought it could make such a difference.
But another Problem appeared, when I have all the effects (one in each of the first 8 loops) before the amp there is no noise but when I have them split, 4 before the amp and 4 in the FX-Loop, I get a lot of noise. When I power the ones in the Loop with batterys it`s gone. I´m using an Ollmann Power Supply, an old german brand that unfortunately doesnt exist anymore but it`s a medium to high quality Power supply. Is there maybe also an easy Solution to this Problem?!
Greetings,
Daniel
 
That sure sounds like a ground loop. Switching to a supply like the Pedal Power 2 Plus, one by Cioks or another isolated supply should fix that for you.
 
I'll remember the 9VAC trick if I run into that problem again. I've always powered them from AC anyway, so not run into the problem running them from DC.

I agree with Ron, definitely a ground loop powering the pedals. It's the same reason people have so many issues running the "4 cable method" with effects processors. Basically, any means of splitting the power between the ones in the loop and the ones before the amp should solve your problem. You want either a supply with isolated outputs, or just a separate power supply for each of the two pedal chains. Probably the cheapest option is the T-Rex Fuel Tank Junior, which has 5 isolated outputs for about €100.
 
The 9VAC trick only works because 99.99% of all wall warts are made as cheaply as possible. A DC output supply. built as cheaply as possible these days, doesn't involve a transformer and isn't fully isolated. Not only that, the crappy switching circuitry in them can generate its own noise. Not an issue when you're charging a cell phone, but a real problem for audio.

An AC output adapter is just a transformer and nothing else, and by definition is isolated - making it not isolated would make it more expensive (or unsafe). They're inefficient and harder to find these days, but AC output is still the easiest to make into a clean power source.

That said, I've found some great DC output adapters, but can't buy them because of enormous minimum order quantities.
 
With my Setup I had to change the Power Supply for the RJM anyway because I´m also powering the GCP with it now so I needed one with 9VAC and 1 or more Ampere anyway :)

Another little, and hopefully last, Question:
If its only about the Effects before the amp and those in the loop, could I also avoid ground loops by daisy chaining all effects before the amp with one power supply (or one isolated output from a good PS) and doing the same with those in the FX Loop?

The Pedal Power 2 Plus for example has only 8 Outputs but maybe I will some day use all 12 Loops for 12 different Pedals and then I would run out of outputs. So would it also work daisy chaning all those before the amp from one output of the PP2P and daisy chaining the ones in the FX Loop with another Output of the PP2P (or any other PS with isolated outputs)?
 
That should be OK... certainly I've powered multiple pedals before the amp with the same output of a power supply without problems (I'm powering my OCD and my boost pedal from the same outlet in my current rig). I see no reason why it shouldn't work for ones in the loop too, but I can't guarantee it. Certainly worth a go, particularly as the pedals you typically put before an amp tend to be quite low current draw.
 
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