rega p2 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 19th August 2006, 05:22 PM   #1
diyAudio Member
 
mpmarino's Avatar
 
Join Date: Jun 2004
Location: Crunchville, where I don't fit in.
Default rega p2 hum

I have a rega p2 (the NAD one) and I'm bothered by hum. It is fitted with a Linn Basik Plus arm and a Grado Black. I have tried a few pre/riaa stages and the symptoms stick. This is at med to high volume only and seems to be a 60Hz hum.

This hum is induced when the cartridge is in proximity of the motor. I've removed the arm and used it like a wand to prove that the internal arm wiring isn't shorting as I swing the arm. It's definitely a proximity issue. I've tried the arm grounded and not...no help.

Could I have issue with the motor? There is a board with a cap and resistor...could that be bad? What does it do? Geez, there is nothing to this thing!

I'm at a loss. I've actually considered putting MU metal under the platter but I'd rather not

please suggest

Thanks,
Marc
__________________
Crazy Yankee.
  Reply With Quote
Old 19th August 2006, 07:36 PM   #2
diyAudio Member
 
Join Date: Nov 2004
Location: Surrey, UK
Hi Marc
The Grados are really great cartridges, but they do have a reputation, especially amongst Garrard owners, for being very susceptible to picking up hum. Having said that, I've used Grado-based cartridges for years (even on a 401) without a problem. I think that bit of gold metal stuff they wrap round them is for more than show!

A cople of toughts:

Assuming the hum's always been there rather than just appeared, maybe you have to take some steps to make sure it's well shielded. First I'd check that the original arm ground is working OK - I think earth grounding for an arm is really important. It might be worth taking an earth connection right up to the headshell.

Perhaps a bit of motor and electrics shielding? - like even some grounded aliuminium foil, nerdy by effective!

regards, Jeff
  Reply With Quote
Old 19th August 2006, 07:49 PM   #3
diyAudio Member
 
mpmarino's Avatar
 
Join Date: Jun 2004
Location: Crunchville, where I don't fit in.
Thanks Jeff,

I recvd the table minus arm and the arm from two different sources. I have had the hum since I put it together... that's all I can say 'bout that.

I have tried a seperate earth and pre ground directly to the arm...not a lick of difference.

Maybe if I stuff the alu foil in my ears

Thanks for the reply
__________________
Crazy Yankee.
  Reply With Quote
Old 19th August 2006, 07:54 PM   #4
diyAudio Member
 
Join Date: Nov 2004
Location: Surrey, UK
Hi, well, I have a p2 and a Grado cartridge around, so I'll put the two together tommorow and see if they hum. If they do , I gues you gotta shield the motor, If not, there must be a fault.

regards, jeff
  Reply With Quote
Old 19th August 2006, 08:00 PM   #5
diyAudio Member
 
mpmarino's Avatar
 
Join Date: Jun 2004
Location: Crunchville, where I don't fit in.
That would be going above and beyond....and appreciated!

Thanks Jeff!
__________________
Crazy Yankee.
  Reply With Quote
Old 19th August 2006, 09:06 PM   #6
tubenut is offline tubenut  South Africa
diyAudio Member
 
tubenut's Avatar
 
Join Date: Nov 2002
Location: South Africa, Jhb
Grado's are very susceptible to hum and the problem you describe is a common Rega/Grado ailment. (The non metal platter offering no shielding from the motor could be the reason for other TTs with metal platters not giving the problem.)
I am afraid that changing the Grado is gonna be your best bet....

Sorry to bear bad news....
__________________
Guillaume
Croak Audio Exploration
  Reply With Quote
Old 19th August 2006, 09:35 PM   #7
diyAudio Member
 
mpmarino's Avatar
 
Join Date: Jun 2004
Location: Crunchville, where I don't fit in.
Thanks tubenut,

It's OK...I can take it The Grado was cheap anyway.
__________________
Crazy Yankee.
  Reply With Quote
Old 20th August 2006, 03:38 AM   #8
maxro is offline maxro  Canada
diyAudio Member
 
maxro's Avatar
 
Join Date: Dec 2004
Location: Survey says: Least happiest city in Canada
Maybe you could run a sheet of mu metal between the glass platter and the mat. Or just shield the motor itself with mu metal.

Max
  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
Rega R5 inside culture Multi-Way 3 14th November 2007 01:41 PM
WTB: Rega arm for parts Algar_emi Swap Meet 0 6th November 2007 09:51 PM
Rega RB300 John Caswell Swap Meet 1 17th October 2007 07:05 AM
AR ES1 Rega 250 Arm Mounting tinmanrrtx Analogue Source 3 11th February 2005 10:02 PM
Simple DIY VTA for Rega ericpeters Analogue Source 1 7th July 2004 03:22 PM


New To Site? Need Help?

All times are GMT. The time now is 02:14 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