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 12th April 2006, 11:19 AM   #11
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
-i am trully sorry - i did not know that this word is that hard.... i looked in the slang dictionary and found what is the correct meaning ....that is what you have when you learn english from the films that our children are looking too
oh well.... i admit i am ashamed and i am sorry.....so lets proceed quickly to the problem that is presented here
__________________
when you burn it - burn it good
  Reply With Quote
Old 12th April 2006, 11:26 AM   #12
diyAudio Member
 
Brian Donaldson's Avatar
 
Join Date: Jan 2003
Location: Texas, Love it or leave it
I'm not bothered; I'm a crass ba$tard. I just think that some peoples wives check up on them to keep them in line...hence the languauge police to help prevent slaps and being forbiden to use the computer.
  Reply With Quote
Old 12th April 2006, 11:29 AM   #13
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
-
__________________
when you burn it - burn it good
  Reply With Quote
Old 12th April 2006, 11:33 AM   #14
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Given that your circuit is preceded by a volume control, I assume that the signal level is fairly healthy. Changing things in the reference chain of the CCS will only affect noise/hum, but you have enough signal not to need to worry.

If you had a smaller signal you might be worried. The LED is quiet but even if you manage to find the old low brightness LEDs, the internal resistance isn't all that low (5R or so) so you don't get particularly good attenuation of power supply hum from the potential divider formed by the LED's internal resistance and R2. Replacing R2 with a crude CCS (DN2540N5 plus two resistors) can help considerably.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 12th April 2006, 11:44 AM   #15
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
EC8010 - thanks .... the problem is to use those exotic parts like DN2540N5 and LND150.... i am living at the end of the galaxy (hm, well it is maybe the begginning actually ) so i can't obtain those parts... but i can use normal ccs with BC550/560 - this would also help i think ........

LED diodes that i have are from some not known type and i have tried to pair them so i have 2 pairs (4 pieces) - one that is brighter and the other that is not that bright.... i would like to avoid that problem by putting something better - not to have those LED's - that was the reason for the original question.... oh well - i might try to find something that is bright and red.....in fact i like their look in the preamplifier - everything is glowing all around....tubes LED's yes, yes - that is what i like - but want to boost the quality if possible (using right now 12B4 tube in that configuration).....
i might also use some capacitor to put in paralel with the LEDS - lets say >10uF......??!!


opinions?
__________________
when you burn it - burn it good
  Reply With Quote
Old 12th April 2006, 11:48 AM   #16
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
OK, if you have trouble getting parts, then use an MJE340 as a crude CCS in place of R2. There's no need to fuss matching LEDs - and you don't want good ones! You want the cheapest nastiest oldest dimmest red LEDs you can find. The nice bright new ones have a much higher internal resistance...

There's no need to put a capacitor in parallel with the LED. Assume 5R internal resistance and that you want the capacitor's reactance at 100Hz to be equal to the LED's internal resistance. That's 330uF. It's hardly worth the trouble.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 12th April 2006, 11:54 AM   #17
diyAudio Member
 
sunrise's Avatar
 
Join Date: May 2005
Location: delta quadrant
Send a message via ICQ to sunrise
oh yes - thank you......will do that .... thanks again
__________________
when you burn it - burn it good
  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
Hitachi FET Substitution poor_lackey Solid State 20 12th March 2011 01:15 AM
6N1/6N3 substitution woodturner-fran Tubes / Valves 7 31st January 2007 01:15 PM
E182CC substitution ? bembel Tubes / Valves 5 11th November 2006 04:11 PM
11k resistor substitution...? mcelaj Solid State 3 6th January 2004 04:31 PM
Substitution MOS for Aleph 3 Miles Teg Pass Labs 7 19th September 2001 04:59 PM


New To Site? Need Help?

All times are GMT. The time now is 08:16 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