Multiple Film Caps in parallel, Problems? - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 22nd February 2011, 07:23 PM   #1
ron944 is offline ron944  United States
diyAudio Member
 
Join Date: Sep 2010
Location: Florida
Default Multiple Film Caps in parallel, Problems?

Hi, I am looking to parallel three 1uf film caps (same manufacturer) in place of existing 3uf caps. I know that Multicap does this internally but will it cause any problems, and if not are there any precautions I need to take.

Thanks,
Ron
  Reply With Quote
Old 22nd February 2011, 07:48 PM   #2
taj is offline taj
diyAudio Member
 
taj's Avatar
 
Join Date: Feb 2005
I think it's usually a good thing because it greatly reduces the capacitor's ESR.

..Todd
  Reply With Quote
Old 22nd February 2011, 09:21 PM   #3
diyAudio Member
 
Join Date: Nov 2007
Location: Dallas
Best is to parallel caps of different construction.
Each covers holes in the other's performance.
  Reply With Quote
Old 23rd February 2011, 11:11 AM   #4
diyAudio Member
 
Join Date: Sep 2009
In response to kenpeter, if these mixed caps are to be used as signal caps, the differences in ESL/ESR of each cap could literally cause different phase shifts in the signal, leading to a real mixed up signal. Tried this before with PIO caps bypassing PP caps, the staging got totally screwed up.

Last edited by quikie22; 23rd February 2011 at 11:13 AM.
  Reply With Quote
Old 23rd February 2011, 11:45 AM   #5
diyAudio Member
 
sepolansky's Avatar
 
Join Date: Nov 2007
Location: Maryland
If using identical caps, wire each pair in opposite directions.
  Reply With Quote
Old 23rd February 2011, 03:42 PM   #6
ron944 is offline ron944  United States
diyAudio Member
 
Join Date: Sep 2010
Location: Florida
I am actually using 3-1uf caps in parallel, one set for the line stage and two sets for the phono stage.
  Reply With Quote
Old 23rd February 2011, 04:27 PM   #7
diyAudio Member
 
Join Date: Nov 2007
Location: Dallas
Quote:
Originally Posted by quikie22 View Post
In response to kenpeter, if these mixed caps are to be used as signal caps, the differences in ESL/ESR of each cap could literally cause different phase shifts in the signal, leading to a real mixed up signal. Tried this before with PIO caps bypassing PP caps, the staging got totally screwed up.
I stand by my statement.
Not going to mix up any signal that has a clear path through either cap.
  Reply With Quote
Old 23rd February 2011, 04:44 PM   #8
diyAudio Member
 
Join Date: Sep 2009
Quote:
Originally Posted by kenpeter View Post
I stand by my statement.
Not going to mix up any signal that has a clear path through either cap.
Not doubting your opinion. I am sure you achieved a good result

Just that my experience did not have such favourable results. I thought I could improve my linestage by paralleling a pair of PIO with my already very good film PP cap. Results were very disappointing. Bass improved (due to larger capacitance) but the imaging suffered, loss depth and staging. Using the caps separately yielded far better results.
  Reply With Quote
Old 23rd February 2011, 04:56 PM   #9
jcx is online now jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
film caps should have the outer foil lead marked - the outer foil should connect to the "driven" low impedance, high signal side to prevent the sensitive circuit's hi-Z input from picking up noise from electric fields

another common substituion problem is when large physical size means you have large loop area from long leads that have to loop down into the smaller case size hole pattern - the bigger loop area picks up more magnetic field noise, adds to the parasitic inductance, lowers the cap's self-resonant frequency

keep leads short, cap bodies close to board/signal path - but don't melt the plastic soldering too close to the body (too samll/"cool" iron is worse as you spend too long and the heat diffuses further along the leads)

Last edited by jcx; 23rd February 2011 at 05:02 PM.
  Reply With Quote
Old 23rd February 2011, 05:33 PM   #10
diyAudio Member
 
Join Date: Oct 2002
Location: SINGAPORE
Quote:
Originally Posted by quikie22 View Post
In response to kenpeter, if these mixed caps are to be used as signal caps, the differences in ESL/ESR of each cap could literally cause different phase shifts in the signal, leading to a real mixed up signal. Tried this before with PIO caps bypassing PP caps, the staging got totally screwed up.
its called smearing, yes i agree with your finding.
  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
paralleling film caps with electrolytic caps jarthel Power Supplies 399 14th September 2014 09:33 PM
Preffered film caps to replace ceramic caps? rg12 Parts 20 2nd September 2010 04:35 PM
Any disadvantage to multiple parallel caps for PS? theAnonymous1 Power Supplies 14 31st May 2009 04:09 PM
Replacing multi-section caps with multiple caps? Sir Trefor Tubes / Valves 1 29th May 2007 10:17 PM
FILM Caps to assist Big ELYT Caps gromanswe Parts 0 9th July 2002 08:16 AM


New To Site? Need Help?

All times are GMT. The time now is 06:06 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