Solution Needed for Ground Loop Hum - Wah Pedal & Multi-Effects Box
Matt Martin
Burn Unit -> Loooper True Bypass box (Yamaha MagicStomop in Loop1 and
a MXR Micro Amp in Loop2) -> Budda SuperDrive 18. All pedals with the
exception of the Yamaha are powered by the Voodoo Lab Pedal Power.
The Yamaha box has it's own dedicated AC Adapter that outputs 12V AC
and 1000mA. I picked up a Pedal Pad to set up my pedals and had a
compartment underneath. I plugged in the Pedal Power and the Yamaha
into the same power strip and ran that out to power in the wall.
Whenever I engage my wah pedal with this configuration, I get a very
noticeable hum which is horrendous when distortion is engaged. I
tried plugging the AC adpater into my Pedal Power and got the same
problem. I also tried running the Yamaha outside of the loop rather
than connected to the bypass box. Same problem. The only way I
solved it was to plug the AC adapter straight into the wall and then
plug in the power strip with the Pedal Power on it separately. Voila,
no ground loop hum when the wah is engaged and quieter rig overall.
Problem is, this is not a convenient setup. I really need to find a
way to isolate that AC Adapter at the power strip or under my pedals
because it will be tough to find three dedicated wall outlets much
less run that AC Adapter from the board to a wall. Is there any power
strip solution to do this. What about the EBTech Hum Eliminator? Any
other suggestions? I'd like to keep that pedal as it does a great job
on modulations and delays when I need them.
Thanks,
Matt
Phil Symonds
"Matt Martin" <qwack...@earthlink.net> wrote in message
news:4414dd1e.04012...@posting.google.com...
not, have you tried plugging it in "upside down"?
Matt Martin
> not, have you tried plugging it in "upside down"?
Phil,
It is only two pronged and I believe I plugged it in both directions
on the power strip.
Some more information that I thought about that all points to the the
power supply on the Yamaha Magicstomp and not a ground loop. First, I
recally that I had both the Pedal Power and the Magicstomp running on
the same power strip before and had no major hum when I engaged the
wah. However, that was with the power strip away from the pedalboard
and near the wall. Every solution I tried where that Yamaha wall wart
was on the pedal board, I got the hum but most noticeably, it was with
the wah when it was engaged. When I went back and plugged that wall
wart into the wall, well away from my pedal board, the noise with the
wah operating was gone.
So, the wah is picking up the frequencies of the Yamaha power supply.
It there a solution to lessen the noise that would still allow me to
place that power supply under my board?
Matt
tempus fugit
because of the close proximity of the Yamaha wallwart to your board (notice
how it disappears when you move the adaptor away from the board?).
I would try to move the wallwart to a different location in the pedalboard
and see if that helps. If not, you could try shielding the wall wart with a
piece of metal (i.e. put a piece of metal between it and the board, or put
it in a metal box). I say the wallwart because I'm guessing that the cables
around the wah are picking up the hum, not the wah itself (it's made of
metal right?)
"Matt Martin" <qwack...@earthlink.net> wrote in message
news:4414dd1e.04012...@posting.google.com...
Phil Symonds
they sell cheap on eBay. Maybe you'll get lucky. You probably have some
flexibilty on the amps, but not the volts.
Phil
The Chris
millenium bypass and some serious mods, there are some clubs I play in
where it's instantly wah hell as soon as I engage it. And this is with
EVERYTHING plugged into my APC UPS!!!
qwack...@earthlink.net (Matt Martin) wrote in message news:<4414dd1e.04012...@posting.google.com>...
Matt Martin
Thanks for some of the feedback. I played around with the wallwart
for the Yamaha and moved it to the opposite end of the board from the
wah. The Pedal Pad AXS is cool in that you can store power and such
underneath in a compartment. Anyhow, I played around with things and
it is definitely the Yamaha MagicStomps power supply that's causing
the problem. I can get it far enough on the other end of the pedal
board to kill most of the hum that the wah was picking up, but, now it
sits under my boost pedal (a MXR Micro Amp) and when I engage that, it
causes a problem. So whichever pedal that is near it has a problem
when that pedal is engaged. When the pedal is not engaged, the hum is
not present. What about modifying the power supply to filter it?
Maybe the metal box idea. What's frustrating is that I bought the
Pedal Power 2 which works like an abosolute champ, but it won't
support the Amp requirements on this pedal. I'll keep looking for
ideas but at least I locked down tonight what the problem is.
This is kind of lame on Yamaha's part to assume that folks would only
use this one pedal for everything, or that the player would be willing
to run a wall wart from their pedal board.
Matt
cab...@hotmail.com (The Chris) wrote in message news:<ce8544b8.04012...@posting.google.com>...
Christopher Bell
soon as you start adding things to the chain that boost power
(overdrives, distortions, etc.) they boost all the ugly stuff too. So,
if there's something close to the wah, and the cable is not doing its job
by shielding out the interference, it could be an easy fix.
Cables are always overlooked - and I'm guilty of the same thing - so
check that out too....
And I understand your frustration with Yamaha. The way I see it, if an
effect can take a battery, it should be able to be powered by a STANDARD
9V adapter - meaning, ALL effects should run using the same COMMON
adapter - but we all KNOW that's not the case... :)
qwack...@earthlink.net (Matt Martin) wrote in
news:4414dd1e.04012...@posting.google.com:
Matt Martin
problems with 'em before. They must not like that big 'ol wall wart
of Yamaha's.
Matt
Christopher Bell <cab...@nospam.hotmail.com> wrote in message news:<Xns9478FC6ECA27ca...@129.250.170.96>...
Christopher Bell
cheezy plastic cables that came with my Boss BCB-6 with George L
cables... Are you telling me to take a 'wait and see' approach??? :) Or
are you saying that hum ISN'T present with your other cables...
qwack...@earthlink.net (Matt Martin) wrote in
news:4414dd1e.0401...@posting.google.com:
tubeguru
If you try placing it at different angles and you notice changes in the hum,
that's probably what it is. Many pedal manufacturers use poor quality
transformers in their power supplies. In this case adding more filtering to
the power supply won't help because the hum is the result of stray magnetism
from a poorly shielded transformer.
tubegurunews:4414dd1e.04012...@posting.google.com...
tempus fugit
"tubeguru" <tube...@att.net> wrote in message
news:ORWPb.88595$6y6.1...@bgtnsc05-news.ops.worldnet.att.net...
Ray Soave
power supply sits as far from my wah as the board permits and the only power
cable the runs past the wah is its own. This keeps things reasonably quiet.
I've never used a wah that wasn't noisy and prone to pick up any stray noise
available. I swear I've picked up radio broadcasts. The George L's are
great -- they keep things neat. They MIGHT reduce the noise some, but not
that I've noticed.
"Christopher Bell" <cab...@nospam.hotmail.com> wrote in message
news:Xns9478766BCE86Aca...@129.250.170.85...
Phil Symonds
between the wall wart and the board. It's cheap and easy. Get it at Target
or Home Depot where they will take a return if you change your mind, even
after you open it.
Phil
Christopher Bell
playing on my Wah! :)
Like I said, some nights it's great, others, if the power is dirty, it's
no good. To make matters worse - we travel with full lights, so I have
florescent tubes at my feet, and faders all around me. Sometimes, they
take their toll.
"Ray Soave" <r...@soave.net> wrote in
news:10114lo...@corp.supernews.com: