phono hum - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

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 28th February 2013, 09:39 PM   #1
NickD is offline NickD  Canada
diyAudio Member
 
Join Date: Sep 2012
Angry phono hum

I'm sure someone out there has the solution that has evaded me so far:

I built a perfboard version of John Broskie's Aikido phono stage. It worked out really well and sounds beautiful. BUT...I seem to have a problem when I connect a 'Le Pacific' MC Pre-Pre. Then I get the hum from hell. The stage is perfect (dead quiet) using medium output MC with a 5x step up transformer, medium output MC with no transformer, low output MC with 10x transformer. But it hates the head amp connection. The PrePre is powered from a SLA battery and it works just fine into my Copland CTA301 phono section with the low-output MC. So, on the surface it would appear that the builds are fine. I've tried every combination of grounding and internal wire shields that I can think of and I am assuming there is a compatibility issue where the phono expects independent grounds and the head amp output is not that...is there a fix? One piece of additional info, I have a 4PDT rotary switch in the phono to select between 2 turntables; again it works fine until the head amp is connected...the object of the project is to run the LOMC through the head amp to the phono, and the MOMC through the 5x step up to the phono. Best sounds all around..'cept for the hum.

Anyone have a solution for this?
  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
Nailing Hum in my Phono Stage steve516 Tubes / Valves 3 17th December 2012 04:05 PM
Hum in phono pre - help please ianc13 Tubes / Valves 3 20th November 2009 10:12 AM
Advice on hum in phono stage smbrown Tubes / Valves 2 4th November 2009 06:46 AM
Hum in phono circuit Bama Slamma Solid State 2 17th March 2007 03:25 AM
hum on preamp phono output ger56 Solid State 0 31st October 2004 04:30 PM


New To Site? Need Help?

All times are GMT. The time now is 11:18 AM.


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