Importance of quality resistors ????? - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, 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 27th October 2008, 11:52 AM   #1
diyAudio Member
 
Join Date: Oct 2006
Default Importance of quality resistors ?????

Hi Everyone, I need some advice. I will be changing the load impedance of my phono stage.
Presently it is set up for 47K ohm, I think they come like that from the manufacturer. My
phono stage is an Audio Research PH3SE and my cartridge is a Micro benz MC M2 on a Clearaudio Unifty 9 arm. Now my question is how important is it to use
high quality resistors? Does the audio pass through that section of the phono stage?

Thanks
  Reply With Quote
Old 27th October 2008, 12:55 PM   #2
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
The load resistor is in parallel with the preamplifier phono-stage. In your case, Benz recommends (from what I am able to determine) 200 to 47,000 ohms, so the noise of a 200 - 47k ohm resistors itself range from 1.8nV to 27nV per root Hz, but this is shunted by the internal resistance/impedance of the MC itself.

I would use the lowest value possible consistent with the front-end design. You may have to experiment a bit to get it right.

read this nice article by Marshall Leach:
http://users.ece.gatech.edu/~mleach/headamp/
  Reply With Quote
Old 27th October 2008, 12:56 PM   #3
diyAudio Member
 
Join Date: Mar 2007
Location: Canandaigua, NY USA
Whether the audio signal "passes through" or is shunted to ground makes no difference. The components are still in the signal path and affect the sound. Now, some claim to hear differences between resistor types, usually preferring the more expensive ones, but once you get to any decent 1% metal film part, I can't tell 'em apart in most applications. I certainly wouldn't use a carbon composition, carbon film, thick film or MOX resistor for a cartridge load.
__________________
I may be barking up the wrong tree, but at least I'm barking!
  Reply With Quote
Old 27th October 2008, 02:26 PM   #4
diyAudio Member
 
Join Date: Oct 2006
Thanks guys, what is the minimum required wattage , I could use? I was looking at some
Vishay and they're rated at very low wattage.....

Thanks
  Reply With Quote
Old 27th October 2008, 02:42 PM   #5
diyAudio Member
 
Join Date: Nov 2005
Location: colorado
I agree with Conrad. Whether in series or parallel, passives
are carrying the signal either to the next stage or to ground.
When a component is modulated the effect of the modualtion
is carried to the next stage or the inverse of the modualtion
in the case of shunting. i.e. if distortion is created when
a signal is shunted to ground that distortion shows up being
sent to the next stage as inverted distortion.
  Reply With Quote
Old 27th October 2008, 04:45 PM   #6
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Quote:
Originally posted by Serratoga
Thanks guys, what is the minimum required wattage , I could use? I was looking at some
Vishay and they're rated at very low wattage.....

Thanks
The Vishays would be fine regardless of their low wattage rating. You are probably talking about a few uW of dissipation at most.
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 27th October 2008, 05:04 PM   #7
diyAudio Member
 
Join Date: Oct 2006
Thank You,
I had the Vishay metal film resistors in mind and the Caddock MK 132 precision metal film.
Has anyone tested either one? Any preferences?

Thanks
  Reply With Quote
Old 27th October 2008, 05:10 PM   #8
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally posted by Serratoga
Thank You,
I had the Vishay metal film resistors in mind and the Caddock MK 132 precision metal film.
Has anyone tested either one? Any preferences?

Thanks
CMF55 or RN55 -- these are readily available from Mouser --
  Reply With Quote
Old 27th October 2008, 06:02 PM   #9
diyAudio Member
 
Join Date: Oct 2006
Hi Jack,
I checked out the Mouser site, not that I would no the difference, why the CMF 55 and not the higher power rated CMF 60 ?

Thanks
  Reply With Quote
Old 28th October 2008, 01:12 PM   #10
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
They just happen to be what I order -- I think that quite a few people have used them in their F5 amplifiers
  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
Bias Supply Quality / Importance luvdunhill Planars & Exotics 15 28th November 2007 11:26 PM
High quality capacitors, resistors Vortex Parts 2 6th March 2004 03:34 AM
Low Value Precision Resistors / Quality 7805 jonclancy Parts 8 28th October 2003 08:28 AM


New To Site? Need Help?

All times are GMT. The time now is 07:12 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