Go Back   Home > Forums > >

Are you really fine with IC voltage regulators ?
Are you really fine with IC voltage regulators ?
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
Old 3rd September 2020, 11:35 AM   #11
edbarx is offline edbarx  Europe
diyAudio Member
 
edbarx's Avatar
 
Join Date: May 2018
Location: Maltese Archipelago
What is wrong with ICs? Is it because they are made out of a single silicon chip and 'components' may leak into each other? Inductive and capacitive parasitics should be minimal due to a chip's size.
__________________
Any fool can make things bigger, more complex, and more violent. It takes a touch of a genius, and a lot of courage, to move in the opposite direction. [Albert Einstein]
  Reply With Quote
Old 3rd September 2020, 11:41 AM   #12
dreamth is offline dreamth  Romania
diyAudio Member
 
Join Date: Nov 2010
there are way too many different aproach depending on the circuit they supply to draw a black and white conclusion......

Last edited by dreamth; 3rd September 2020 at 11:43 AM.
  Reply With Quote
Old 3rd September 2020, 12:34 PM   #13
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Are you really fine with IC voltage regulators ?
Let's say you are looking at PSRR or Zout of a regulator with a precision vector network analyzer -- you set the bandwidth to perhaps 10Hz and sweep from 100Hz to 10MHz -- fine, you can plot these parameters vs frequency -- adequate for most applications.

For audio, perhaps not. The error amplifier in most regulators is not of the same class as a high end TI or ADI. If you put a signal on the output rail and take an FFT you'll see that harmonics show up -- and this is the cause for smearing and veiling, poor translation of percussive instruments.

This was pointed out by a correspondent to the Linear Audio article on comparison of popular regulators, ain't original to me. I was heartened that his comment, and the FFT's I later created matched up with the subjective impression of the listening panel. The Jung-Didden and Per Ander's Sjostrom ranked tops with very little distortion.
  Reply With Quote
Old 3rd September 2020, 12:39 PM   #14
ginetto61 is offline ginetto61  Italy
diyAudio Member
 
Join Date: Sep 2009
Location: Milano
Are you really fine with IC voltage regulators ?
Could a LM78xx be used instead only as voltage reference for a bjt ? i mean with the LM78xx out driving the bjt base
In this way only the bjt provides the output current.
__________________
“And is it any wonder That the monkey's confused” ― Roger Waters
  Reply With Quote
Old 3rd September 2020, 12:42 PM   #15
dreamth is offline dreamth  Romania
diyAudio Member
 
Join Date: Nov 2010
you're asking the same question in more than one topic...i already answered you in the other topic...
  Reply With Quote
Old 3rd September 2020, 12:59 PM   #16
ginetto61 is offline ginetto61  Italy
diyAudio Member
 
Join Date: Sep 2009
Location: Milano
Are you really fine with IC voltage regulators ?
i am attaching the schematic i have in mind to overcome the fact the zener diodes are not good voltage reference
The LM acts only as a voltage reference and drives the bjt base that actually provides voltage to the load
The LM is not providing voltage to the load at all
Attached Images
File Type: jpg regulator.JPG (38.5 KB, 584 views)
__________________
“And is it any wonder That the monkey's confused” ― Roger Waters

Last edited by ginetto61; 3rd September 2020 at 01:02 PM.
  Reply With Quote
Old 3rd September 2020, 02:18 PM   #17
edbarx is offline edbarx  Europe
diyAudio Member
 
edbarx's Avatar
 
Join Date: May 2018
Location: Maltese Archipelago
As far as I always knew, since I was a sixth form student back in 1985, Zener diodes are the foundation of voltage references. If you want more precision, supply a reference Zener diode through a constant current source and use a buffer amplifier to avoid loading it. One of the best, with regards to temperature stability, I remember, is a 6.8V Zener diode which has zero temperature coefficient.
__________________
Any fool can make things bigger, more complex, and more violent. It takes a touch of a genius, and a lot of courage, to move in the opposite direction. [Albert Einstein]

Last edited by edbarx; 3rd September 2020 at 02:20 PM.
  Reply With Quote
Old 3rd September 2020, 02:20 PM   #18
analog_sa is offline analog_sa  Europe
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Cascais
Are you really fine with IC voltage regulators ?
Where did this thread get born? In vacuum? Never heard of the countless discussions about audibility of various PS approaches? Passive vs active, discrete vs integrated, series vs shunt?

Seriously?

CJ and the other dinosaurs ARC are great examples for audio conservatism. Took them 30 years to figure out that nfb is counterproductive in a preamp, just pathetic. In another 30 they may even discover shunt regulation.
  Reply With Quote
Old 3rd September 2020, 02:25 PM   #19
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Are you really fine with IC voltage regulators ?
^ That's not a good way at all. You are throwing away the the regulation of the chip because the pass transistor is not within any feedback loop plus you are getting a slightly lower output voltage than the chip alone. You also need a higher overhead for the circuit to work properly.

Also some regulators need a minimum load current (particularly some negative ones).

With anything like this you need to define your own requirements first and then see if those requirements can be met with an off the shelf part or, whether you really do need to go further with a dedicated design to get the specification you want.
  Reply With Quote
Old 3rd September 2020, 02:39 PM   #20
dreamth is offline dreamth  Romania
diyAudio Member
 
Join Date: Nov 2010
Quote:
Originally Posted by edbarx View Post
As far as I always knew, since I was a sixth form student back in 1985, Zener diodes are the foundation of voltage references. If you want more precision, supply a reference Zener diode through a constant current source and use a buffer amplifier to avoid loading it. One of the best, with regards to temperature stability, I remember, is a 6.8V Zener diode which has zero temperature coefficient.
it is stated in the art of electronics that the 6.0v zener has zero tempco but if you look in some manufacturer's datasheet you see that the 5.1v is the ov tempco...
anything between 5.1 and 6.2 will do the job.
they used CRD in the past for zener regulation:

https://www.datasheets360.com/pdf/5903155689177736882
Attached Images
File Type: png kenwood l-a1-20v regulator.png (85.9 KB, 470 views)
File Type: png kenwoodl-a1regulators.png (182.1 KB, 457 views)

Last edited by dreamth; 3rd September 2020 at 02:43 PM.
  Reply With Quote

Reply


Are you really fine with IC voltage regulators ?Hide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Plate voltage with/without tube (for fine tune bias adjustemnt) Achi70 Tubes / Valves 21 4th January 2014 04:04 PM
Using a zener diode as voltage reference with variable voltage regulators ginetto61 Power Supplies 14 20th September 2009 02:55 PM
Pre amp voltage regulators help. AMV8 Solid State 19 6th April 2007 10:30 PM
voltage regulators odysseybmx414 Chip Amps 23 2nd January 2006 09:35 PM
voltage regulators GAK Tubes / Valves 12 25th January 2004 05:34 PM


New To Site? Need Help?

All times are GMT. The time now is 01:47 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki