Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

LT3080 High Voltage Floating Regulator
LT3080 High Voltage Floating Regulator
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 6th December 2017, 03:05 AM   #21
crazyfrog is offline crazyfrog  Canada
diyAudio Member
 
Join Date: May 2009
LT3080 High Voltage Floating Regulator
Do you have few PCBs on hand?


Quote:
Originally Posted by Ketje View Post
Try it like this
Mona
  Reply With Quote
Old 6th December 2017, 11:04 AM   #22
bandol83 is offline bandol83  France
diyAudio Member
 
Join Date: Nov 2004
Location: near Bandol, French Riviera
Hi,

My idea in the last line of my 4th December post was the good one

This morning I had the time to test the power supply again and I reduced the length of the cable to the pot from 10 inches to less than 1 inch (about 2 cm) and... Bingo The power supply is now working perfectly with 309 V DC output for 246 V AC from the R-core transformer on the input and 332 V DC after rectifiers (see photos)... I can even increase output voltage up to 325 V DC until the LT3080 has not enough voltage to work correctly ! These tests were done with a 220k load, I will now test the power supply in real conditions with the tube RIAA preampli...

Cheers,
Marc
Attached Images
File Type: jpg test alim HT.jpg (340.8 KB, 318 views)
File Type: jpg test alim HT gros plan.JPG (173.2 KB, 316 views)
  Reply With Quote
Old 11th December 2017, 09:36 PM   #23
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Default How to rid that mains frequency hum?

Hello All,

Hey I am a bit slower with this than I planned. I have access to an AP analyzer for a while.

The first regulator Hooked up is the shunt regulator kit from K&K Audio, for the heater regulator there is a Tent Labs filament regulator.

Hats off to MerlinB.

First off I used the bench high voltage supply and adjusted the 12B4 voltage and current to minimize the valve noise, B+ 156vdc, grid -17vdc. Then the prototype H+ and L+ power supplies were attached to the valve circuit.

The output transformer is a Transendar. The input voltage to the valve grid was adjusted for a measured voltage of 0.114 RMS volts across the 70ohm resistor placed at the output of the transformer. This will be very near 90dB output from the LCD 2 headphones.

See the attached plots.

The prototype supplies with regulators worker out very well.

The -120dBV mains 60hz peak plexes me. It just seems to come out of the air and will not go away. If I turn off the heater supply the 60hz peak disappears. Keep in mind -120dBV is 1 PPM, or 0.000001 RMS volts.

I do not recall seeing many or any valve circuit FFT’s where the mains frequency is absent. Many posters append that part of the plot.

DT
Attached Images
File Type: jpg 12B4 with regulators FFT.jpg (63.8 KB, 276 views)
File Type: jpg 12B4 with regulators Sweep .jpg (77.0 KB, 268 views)
  Reply With Quote
Old 11th December 2017, 10:09 PM   #24
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
LT3080 High Voltage Floating Regulator
Quote:
Originally Posted by DualTriode View Post
I do not recall seeing many or any valve circuit FFT’s where the mains frequency is absent. Many posters append that part of the plot.

DT
Stereophile is just showing an IMD chart -- which is, of course, very useful. I don't know if the SYS2522 supports IMD.

You can make the 60/120Hz go away by using a linear abscissa!
  Reply With Quote
Old 11th December 2017, 10:52 PM   #25
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Thank you jacjinnj,

The APx555 I am using will also do multi-tone IMD testing. I used the FFT to show the ubiquitous 60hz power line noise.

You say “You can make the 60/120Hz go away by using a linear abscissa!” please tell me more.

DT
  Reply With Quote
Old 12th December 2017, 12:21 AM   #26
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
LT3080 High Voltage Floating Regulator
Quote:
Originally Posted by DualTriode View Post
You say “You can make the 60/120Hz go away by using a linear abscissa!” please tell me more.

DT
Change the sweep from logarithmic to linear.
  Reply With Quote
Old 12th December 2017, 03:12 PM   #27
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Default removing a little 60 cycle ripple

jacjinnj,

I seem to be missing something with this typing and posting we are doing.

You appear to be speaking of the scale of the plot.

I am speaking of removing a little 60 cycle ripple from the performance of the DUT.

DT
  Reply With Quote
Old 12th December 2017, 09:46 PM   #28
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Default Maita regulator

This is the 21st LT3080 Maita regulator.

Looks to be within noise specification.

The same test configuration as above.

I like the looks of the shunt regulator much better.

Old school to follow later.

DT
Attached Images
File Type: jpg 21 maita FFT.jpg (79.6 KB, 242 views)
File Type: jpg 21 Maita Sweep.jpg (76.7 KB, 64 views)
  Reply With Quote
Old 13th December 2017, 01:34 PM   #29
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
LT3080 High Voltage Floating Regulator
I was just being facetious wrt the abscissa!

The LT3081 datasheet PSRR vs Frequency chart, @60 Hz @room temperature =~80dB.

Just throwing in this chart of PSRR vs Frequency for various. The Salas shunt is excellent in this regard, but it has some issues with "reverse-PSRR"
Attached Images
File Type: gif LineRejection_Pos.gif (43.8 KB, 80 views)
  Reply With Quote
Old 13th December 2017, 11:58 PM   #30
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Jackinnj,

Thank you for posting your chart. I went back and reread your LA power supply bake off article.

The positive voltage half of the Jung/Didden Super Regulator with -120dB rejection at 60Hz may make a good valve heater power supply. I went to the diyAuydio Store and purchased a PCB to give it a try.

Did you plot distortion vs frequency sweeps or FFT’s at the output of the JFet line stage in your power supply bake off, seems like that would be a good place to measure the effects of the various power supplies? Measured effects vs perceived quality would be interesting.

DT
  Reply With Quote

Reply


LT3080 High Voltage Floating RegulatorHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Linear's LT3080 Regulator jackinnj Power Supplies 23 29th May 2016 02:04 PM
High Voltage Regulator mod_evil Power Supplies 36 28th October 2011 12:48 PM
high voltage regulator wleediy Solid State 2 4th August 2009 07:12 AM
High voltage, high current super regulator, possible group buy peranders Group Buys 54 2nd June 2009 09:43 AM


New To Site? Need Help?

All times are GMT. The time now is 03:35 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki