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DIY Stompboxes => Building your own stompbox => Topic started by: Austin73 on April 01, 2007, 10:37:54 AM

Title: Noisey UK Mains!
Post by: Austin73 on April 01, 2007, 10:37:54 AM
Hi everyone, bit of a leftfield topic but having a few problems with noisey mains supply in my house. When using my Alesis phlnger, tremelo and phaser i'm getting a really bad hum/crackle rendering any sound from them as useless! It only seems to affect these pedals as they run on 9v AC is there anything out there that could filter this out as I can't afford to rewire the house at the mo! lol

Hope you can help

Cheers

Aus
Title: Re: Noisey UK Mains!
Post by: darron on April 01, 2007, 10:48:12 AM
are you using a regulated power supply? if it's unusable then i'd say that you are not. i hate it when i see people using unregulated power supplies.... i feel like slapping them, and then i end up giving away one to them. i don't even have one left for myself at the moment.... ... :'(

ermm.... i'm really getting carried away. i should stop posting for tonight!
Title: Re: Noisey UK Mains!
Post by: Austin73 on April 01, 2007, 10:57:16 AM
cheers darron its the power supplys that came with the pedals

Title: Re: Noisey UK Mains!
Post by: darron on April 01, 2007, 11:01:00 AM
Quote from: Austin73 on April 01, 2007, 10:57:16 AM
cheers darron its the power supplys that came with the pedals



arg. that's a bit different then i suppose? still, does it say that it is regulated? maybe it worked fine where the developer was from, or maybe they changed over and just assumed things would be alright in doing so :S

are you sure that crackle would be a word that describes the problem well? crackle makes me think of an intermittent poor connection somewhere.

i'm off to sleep. good night.
Title: Re: Noisey UK Mains!
Post by: Aharon on April 01, 2007, 12:15:37 PM
Are they grounded plugs or just two prongs?.
Is there any shops nearby that could cause problems,like somebody running electric motors etc.?
If you don't have access to a power conditioner maybe you can get one of those IEC sockets with the filtering caps and inductor built in,and build yourself a power strip.
That's what comes to mind......
Aharon
Title: Re: Noisey UK Mains!
Post by: R.G. on April 01, 2007, 04:47:56 PM
There exist line conditioning filters that are supposed to filter out the transient and noise junk.

Some of them work.
Title: Re: Noisey UK Mains!
Post by: col on April 01, 2007, 06:49:07 PM
Is it just those pedals or could it be a noisy patch lead/guitar lead/guitar pot/guitar jack/power connector/amp jack instead?
Title: Re: Noisey UK Mains!
Post by: brett on April 01, 2007, 07:39:52 PM
Hi
You can install 2 single-pole filters.  That fixed a mate's system that ran off a completely trashy generator.
From memory, each filter was a series 3.3 ohm resistor, then 2200uF cap to ground.
cheers
Title: Re: Noisey UK Mains!
Post by: Paul Perry (Frostwave) on April 02, 2007, 04:30:22 AM
Seein that they are 9v *AC* (not DC) input pedals, maybe something is beig capacitively coupled from one side of hte mains thru the transformer. Maybe one of those plug boards with a built-in interference filter would help. Maybe a mains isolation transformer would help (not guaranteed though, and heavy and expensive). Maybe if ther eis a choice of mains sockets in the room, changing which gear is plugged into which one could help (in particular, I would have the effects & the amp running from the same mains socket).
Title: Re: Noisey UK Mains!
Post by: MartyMart on April 02, 2007, 06:44:09 AM
My studio is all powered from a Pete Cornish filtered power board, which "found it's way" into
my rack case many moons ago  :icon_wink:
I dont ever seem to get spikes or noise, though I do get some "disk drive whine" when using high
gain guitar signal too near the computer !!

MM./