RFI problems - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th February 2004, 09:12 AM   #1
laz is offline laz  Australia
diyAudio Member
 
Join Date: Dec 2003
Location: adelaide
Unhappy RFI problems

Need help.Ive got a Perreaux 9000B power amp and Perreaux SA2 preamp .Ive made up some leads using good quality shielded mic cable using rca's on the pre going to xlr's on the power.I'm getting rfi{AM radio} coming through when there connected together.When I switch the pre on it gets slightly louder.If i unplug the leads on the pre and leave them plugged in on the power the rfi is gone although volume control doesnt increase the noise when there plugged together.Also is it normal to get loud hum if you touch the rca's body when there not plugged into the pre amp only on the power amp.I've gone from active on the rca to pin 3 on the xlr and neutral on rca to pin 2 on xlr and shield only on pin 1.RE Laz
  Reply With Quote
Old 18th February 2004, 03:27 PM   #2
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Going from unbalanced to balanced without a transformer, or active circuitry can cause problems. However, I think you've made them worse for yourself by the pins you have chosen. Try this:
pin 2 - inner
pin 3 - outer (shield)
pin 1 - either leave unconnected, or connect to pin 3

Remember to check the pin numbers on the XLR plug; they're not logical
  Reply With Quote
Old 19th February 2004, 03:47 AM   #3
laz is offline laz  Australia
diyAudio Member
 
Join Date: Dec 2003
Location: adelaide
Thanks dhaen.I wired the connectors that way because for some reason on the back of the power amp it states that pin 3 is +ve and pin 2is-ve I think Perreaux wired them that way for some reason if i'm not wrong.Do you think I should still drop the shield and/or still wire the the pin1 with pin2.Thanks Laz.
  Reply With Quote
Old 21st February 2004, 07:06 AM   #4
laz is offline laz  Australia
diyAudio Member
 
Join Date: Dec 2003
Location: adelaide
Also when I used the preamp with a normal perreaux 1150 B poweramp unbalanced the RFI was still a problem.Someone please help!
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
GFA-565 problems ben62670 Solid State 5 14th August 2008 06:36 AM
HK AVR 335 Problems utjay2008 Solid State 0 21st October 2007 02:26 AM
Nak dvd-10s problems MadMutt Digital Source 8 26th March 2007 10:06 AM
Sub Amp Problems Thanks! crippledchicken Solid State 2 10th January 2007 06:17 PM
JLH problems serosmaness Solid State 11 2nd November 2004 06:17 PM


New To Site? Need Help?

All times are GMT. The time now is 01:26 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2