It is currently Mon Mar 16, 2020 11:08 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 5 posts ] 
Author Message
Post subject: Acoustasonic 30 DSP hum
Posted: Thu Mar 29, 2012 6:38 pm
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 28, 2012 7:57 pm
Posts: 1
I've encountered the following symptom with my Acoustasonic 30 DSP and I'm wondering if anyone else has run into it.

If I plug the 1/4" line out signal from the Acoustasonic into a PA, the PA immediately emits a loud 60 cycle hum, even if the Acoustasonic is not even turned on. The hum disappears as soon as I disconnect it from the PA.

If I use a ground isolation cord (AC power cord with no ground wire) to power the Acoustasonic, there is no hum at all when plugged into the PA.

This has happened in two separate venues, using two different PA systems.

Anyone else seen this? At the first venue, I thought maybe house wiring problem, ground loop due to faulty wiring (it was a really old building), but then it happened at the next place with much more up-to-date wiring...

Possible fault in my Acoustasonic?

Thanks for any info!


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Acoustasonic 30 DSP hum
Posted: Fri Mar 30, 2012 2:10 pm
Offline
Professional Musician
Professional Musician

Joined: Sun Dec 19, 2010 12:00 pm
Posts: 1389
You probably have a ground loop that is never good for hum. Another possibility is to have an isolation default in you PA ar amp, I suppose that you use a shielded cable.

First, try to measure the ground continuity between the PA plug and the PA input jack with a multimeter in "ohmmeter" (should be almost 0 ohm). Same with you amp. Both amp pluged but not connected by a cable, mesure in AC voltmeter if there is a differntial voltage.

Take care if you are not skilled in electrical engineering.
Let me known results
8)

_________________
Tissan

*'52 Telecaster RI, '57 Stratocaster RI, Gibson ES175 RI, Washburn Hawk 1980, Epiphone Casino MIK 2000, 57' Deluxe Knotty Alder, BDRI ...*
https://soundcloud.com/pierrou
http://www.youtube.com/user/Jazzenfamille


Top
Profile
Post subject: Re: Acoustasonic 30 DSP hum
Posted: Mon Jun 04, 2012 7:39 am
Offline
Hobbyist
Hobbyist

Joined: Thu Jun 03, 2010 3:54 am
Posts: 4
All Fender Acoustasonics are junk with poor parts support. Stay away from them. They are junk. Period.

"You get what you pay for...sometimes"


Top
Profile
Post subject: Re: Acoustasonic 30 DSP hum
Posted: Tue Nov 12, 2013 12:53 pm
Offline
Hobbyist
Hobbyist

Joined: Tue Feb 22, 2011 3:41 pm
Posts: 5
Make sure that your balanced line cable that you are using as an interconnect between the amps d.o. and the house board doesnt have the shield grounded to the outer housing of the xlr connector's shell. This shielding grounds to both components chassis' s . Many sound reinforcement components now are using switching power supplies and also seeing many class d power amps too. These devices have floating grounds above the chassis potential on the primary supply side much similar to the way televisions are designed. When the two components are intercomnected it creates an unbalanced potential and resulting ground loop condition where the 60 cycle appears on the signal.
Seems like some xlr's have the signal shielded to the outer plug housing and some don't. I dont know if this is why or not? Maybe someone else can explain it better, because I am not fully sure that my description is 100% technically accurate... but it sounds like I know what I am talkn bout and maybe ya get the basic idea anyways. Somebody please chime in that can confirm or correct what I am trying to elaborate on. :oops: :oops:


Top
Profile
Post subject: Re: Acoustasonic 30 DSP hum
Posted: Tue Nov 19, 2013 6:40 am
Offline
Rock Star
Rock Star
User avatar

Joined: Tue Aug 07, 2007 2:19 pm
Posts: 8827
I use a Fishman, never had a problem. Does seem like a ground loop problem. Check your cables too.

_________________
Life...... It's sexually transmitted and always fatal


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: