Best low noise regulator? - Page 15 - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 3rd March 2009, 11:49 PM   #141
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
salas, see the curve with the resistor (attached) to infer db improvement. 7.43mA going through the bc550c. It is almost the Idss of the jfet above it (since I modified the 2sk170 model to simulate at about 7.5mA Idss).
Attached Images
File Type: jpg salasb4.jpg (26.4 KB, 605 views)
  Reply With Quote
Old 3rd March 2009, 11:56 PM   #142
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
I know you don't like opamps in the regulator, so you may not like this one that I'm playing with now. But it's not very bad (see attached).
Attached Images
File Type: jpg somereg2.jpg (34.9 KB, 592 views)
  Reply With Quote
Old 4th March 2009, 12:02 AM   #143
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
So its about 20dB better with just substituting R6 for an Idss 2SK170 and absolutely no other changes? Like here in the attachment? If yes, OK no problem, I will mod it and listen carefully. The BC550C goes to 156mW with 7.5mA so it does not seem to be a problem.
Attached Images
File Type: gif r6=idss.gif (6.7 KB, 742 views)
  Reply With Quote
Old 4th March 2009, 12:07 AM   #144
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally posted by ikoflexer
I know you don't like opamps in the regulator, so you may not like this one that I'm playing with now. But it's not very bad (see attached).
I will listen to what the JFET CCS does instead of the resistor first. On the other hand you saw the shunt + phono scope traces for noise, and my FFTs with 100Hz buzz at -107dB of shunt+phono, so I don't know what all those nice additions will practically do. But I am curious. Make the super sim and listen to it too VS your second best, would be my suggestion.
  Reply With Quote
Old 4th March 2009, 12:14 AM   #145
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Yes, that's the only change I've made. I'd say, while simulation is fun, please let me know what happens in reality.

I have to say again, this is all academic. I too, at the end of the day like practical solutions. But man, getting another 80db improvement in the simulator beats sudoku any day for me I will put this one through a battery of tests and if it survives I'll prototype it too, nothing to lose. And, you'd be surprised how well the opa134 works in a regulator
  Reply With Quote
Old 4th March 2009, 12:16 AM   #146
syn08 is offline syn08  Canada
Account disabled at member's request
 
Join Date: Aug 2005
Location: Toronto
Quote:
Originally posted by ikoflexer
Until then, this is how it sims (jfet replaced R6).
Check the loop stability, I smell trouble.
  Reply With Quote
Old 4th March 2009, 12:26 AM   #147
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
I like the soft trend of rise and phase that you simulated on the simple ones. Now if the resistor one that I have in use now, really does 74dB, if we assume 200mV peak to peak ripple from a wall wart DC in (not the fast bridge and 33R to 10mF Slit Foil that I really use), it will divide it by 5000 times. 0.04mV 100Hz ripple at the phono B+. If it only does 40dB then 2mV P2P. And then there are local RC filters...No wonder it does not buzz.
  Reply With Quote
Old 4th March 2009, 12:29 AM   #148
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally posted by syn08


Check the loop stability, I smell trouble.
Thanks Syn08. I will just install it instead of R6 and will check for real. If it burns a BJT and a Mosfet, no worries. I spend as much a day for cigs and they do me no good. Instead I will inhale magic smoke.
  Reply With Quote
Old 4th March 2009, 12:53 AM   #149
jwb is offline jwb  United States
diyAudio Member
 
jwb's Avatar
 
Join Date: Mar 2002
Location: San Francisco, USA
Send a message via AIM to jwb
Hey salas, I really like the look of that last one. I think I might try it!
  Reply With Quote
Old 4th March 2009, 12:58 AM   #150
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
OK I got a partner! But we if we come back with posted photos of burned regs, syn08 rang the bell early! Fair is fair!
  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
Reducing regulator noise. Predator864 Power Supplies 3 23rd March 2008 07:26 PM
Regulator Output Noise Voltage Spec TerryC Parts 2 23rd January 2006 04:46 AM
wanted: suggestion for a low noise regulator circuit. Raj1 Digital Source 8 30th January 2004 06:55 PM
Ultra low noise JFET voltage regulator Kochkurov Maxim Digital Source 6 25th January 2004 11:33 AM
ForSale: LT1085CT Low noise Regulator tone Swap Meet 0 10th September 2003 06:22 AM


New To Site? Need Help?

All times are GMT. The time now is 09:17 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