Best cap to cathode tube bypass is .. - 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 16th January 2006, 10:28 AM   #1
Katapum is offline Katapum  Europe
diyAudio Member
 
Join Date: Mar 2003
Location: Europe
Default Best cap to cathode tube bypass is ..

Hi all,


Id to know what is the best cap to cathode tube bypass. The 300B amp needs a 120uF/6.3Vcap.
I have in my place:

Panasonic FC
Rubycon YXF
Sanyo oscon
Elna RJH

Any comments or suggestions are very welcome (and sorry my English).

Katapum
  Reply With Quote
Old 16th January 2006, 10:35 AM   #2
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
I dunno about the best,but I've heard the Oscon's are pretty good for cathode bypass duty.I havn't tried it myself though,yet.

6.3V ? are you sure about that? Seems low to me..
  Reply With Quote
Old 16th January 2006, 12:49 PM   #3
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Where in the circuit is this used?
__________________
And while they may not be as strong as apes, don't lock eyes with 'em, don't do it. Puts 'em on edge. They might go into berzerker mode; come at you like a whirling dervish, all fists and elbows.
  Reply With Quote
Old 16th January 2006, 12:55 PM   #4
diyAudio Member
 
Join Date: Sep 2003
Location: London
You can get 100uF in motor run caps. Big, but good. I use ICW polypropylenes rated 160uF. Big but very good.
  Reply With Quote
Old 16th January 2006, 03:23 PM   #5
Katapum is offline Katapum  Europe
diyAudio Member
 
Join Date: Mar 2003
Location: Europe
Quote:
Where in the circuit is this used?

in input stage (not in 300B stage).

Quote:
You can get 100uF in motor run caps. Big, but good. I use ICW polypropylenes rated 160uF. Big but very good.
Amp has no room to big caps.


Katapum
  Reply With Quote
Old 16th January 2006, 04:08 PM   #6
diyAudio Member
 
Join Date: Jul 2004
Location: ottawa
Andy,

I've been thinking about using motor run caps for bypass. Were they noticeably better sonically than good elctrolytics (BG or other)?

Jonathan
  Reply With Quote
Old 16th January 2006, 06:21 PM   #7
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Why not lose the cathode bypass cap and bias up the input tube in some cleaner way?
__________________
And while they may not be as strong as apes, don't lock eyes with 'em, don't do it. Puts 'em on edge. They might go into berzerker mode; come at you like a whirling dervish, all fists and elbows.
  Reply With Quote
Old 16th January 2006, 08:47 PM   #8
Katapum is offline Katapum  Europe
diyAudio Member
 
Join Date: Mar 2003
Location: Europe
Hi,

Quote:
Why not lose the cathode bypass cap and bias up the input tube in some cleaner way?


Could you elaborate?
(Input tube is a triode; the amp has only two stages with no feedback.)

Katapum
  Reply With Quote
Old 16th January 2006, 08:49 PM   #9
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
If you can sketch out the input stage, perhaps we can look at some alternatives.

Sorry, I just hate cathode bypass caps. Nasty things.
__________________
And while they may not be as strong as apes, don't lock eyes with 'em, don't do it. Puts 'em on edge. They might go into berzerker mode; come at you like a whirling dervish, all fists and elbows.
  Reply With Quote
Old 16th January 2006, 08:54 PM   #10
Giaime is offline Giaime  Italy
diyAudio Member
 
Giaime's Avatar
 
Join Date: Oct 2004
Send a message via MSN to Giaime
If you can live whitout 3dB of gain, what's the problem? Just leave it out! Stuart, am I wrong? Does the first stage need to be fully redesigned? Just make up for the lost gain with a little increase in plate resistor (or tube change)...
  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
2A3 without cathode bypass cap??? papparazzi Tubes / Valves 30 31st July 2014 11:44 PM
Calculating cathode bypass cap. G Tubes / Valves 8 12th April 2007 05:50 PM
Which BG cap best suited for cathode bypass? reaction Tubes / Valves 10 25th April 2005 08:43 AM
Cathode bypass cap ? woody Tubes / Valves 2 19th May 2002 06:53 AM
Best Cathode Bypass Cap Mohan Varkey Parts 4 6th May 2002 09:59 PM


New To Site? Need Help?

All times are GMT. The time now is 02:41 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