CD player output caps - calculations - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, 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
Thread Tools Search this Thread
Old 25th May 2005, 03:10 PM   #1
diyAudio Member
reaction's Avatar
Join Date: Jun 2004
Location: Bulgaria
Default CD player output caps - calculations

I am about to upgrade the stock electrolytics on the output of my player. They are 220uF Nichicon Muse, bypassed with 0.47uF MKP caps. I think to replace them with 3-4uF (>4uF are too expensive for my budget) film and foil Multicaps without additional bypass. The problem is that I don't know how to calculate whether ~3-4uF is enough capacitance to avoid audible bass roll-off. My tube amp next to the player has about 50k input impedance. If 3-4uF is not enough I could buy 10-15uF lower grade metallized polypropylene Multicaps instead.

Does anybody could help me to calculate the output caps value? Thanks in advance.
  Reply With Quote
Old 25th May 2005, 03:52 PM   #2
bocka is offline bocka  Germany
diyAudio Member
Join Date: Jul 2003
Location: Hannover
The cutoff frequency fc of a first order low pass is given by

fc = 1 / (2 * Pi * R * C)

If you rearrange the formula you can calculate C

C = 1 / (2 * Pi * R * fc)

Assuming that fc should be 5Hz max. your Cap must have at least 636nF. 3 to 4F should be sufficiant for your player.
  Reply With Quote
Old 26th May 2005, 08:24 PM   #3
diyAudio Member
makinson1's Avatar
Join Date: Aug 2004
Location: Tallahassee, FL
If the pre-amp has input caps, why do you need output caps in the CD player? Aren't they redundant?
  Reply With Quote
Old 27th May 2005, 06:17 AM   #4
diyAudio Member
reaction's Avatar
Join Date: Jun 2004
Location: Bulgaria
My pre-amp doesn't have input caps.
  Reply With Quote
Old 28th May 2005, 09:32 AM   #5
diyAudio Member
Join Date: Jan 2004
Location: Stockholm
Check resistor value to ground in the CD-player.
This should be from output to ground somewhere after the capacitor.
Often this is 10k or similar. In my experience this is not good.
Dont know why they are doing this. 100k is a lot better.
Not only can you use a smaller, better quality capacitor, but it also improves sound quality in terms of dynamics, headroom etc.

If you want no influence from Fc on frequency response, Fc should be around 1/10 of the lowest frequency you want to reproduce .
So if you want 30Hz with no roll-off go for 3Hz as Fc etc.

MultiCap RTX are very good but fairly expensive. Mundorf silver capacitor might be very good, but I havent tried them.

For those so inclined Black Gate migth work, but they have some high frequency coloration or something. Sanyo SEP seems good, but I havent listened to them yet for more than a couple of hours.
  Reply With Quote
Old 28th May 2005, 02:37 PM   #6
diyAudio Member
makinson1's Avatar
Join Date: Aug 2004
Location: Tallahassee, FL
Any body tried bypassing the Black Gate or Tonerex with small value silvered mica? (I know, it sounds like silver!). There could be worse things.
  Reply With Quote


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
Lots of free caps and an SACD player Ric Schultz Swap Meet 27 6th August 2006 03:35 AM
Lifetime calculations for electrolythic caps Lars Clausen Power Supplies 7 13th June 2005 01:53 PM
CD Player Output Vs. Preamp Output For A Sub. kspv Multi-Way 3 16th April 2004 10:45 AM
power output calculations, rated power and required power output metebalci Tubes / Valves 7 22nd February 2004 05:49 PM

New To Site? Need Help?

All times are GMT. The time now is 03:29 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2