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 14th June 2017, 01:26 AM   #11
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 jackinnj View Post
Bare board is $50. The secret sauce is illustrated above and on his posts.
Just got one of Tom's new boards today --
  Reply With Quote
Old 15th June 2017, 11:21 PM   #12
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Default Compare notes?

I am expecting a couple of these in a day or two. Lets compare notes regarding PSRR and noise.

High Voltage Regulator

DT
  Reply With Quote
Old 16th June 2017, 02:57 AM   #13
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 admire Pete's work, but the LT3080 seems to offer an improvement of 20dB PSRR compared to the HV Maida.
  Reply With Quote
Old 16th June 2017, 07:12 AM   #14
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Default 20dB’s of difference

I don’t have a dog in the hunt other than noise and PSRR are important.

I think that I will build one of each and see how they test. The data sheets do not show 20dB’s of difference.

The thing that irritates me some is that Tom used the open source and network of diyAudio to develop his project. After everyone’s generous help his project is now personal proprietary property.

DT
  Reply With Quote
Old 1st September 2017, 04:21 PM   #15
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
LT3080 High Voltage Floating Regulator
If you're going to roll your own, i.e. have a PCB burned, you might want to consider putting a guard ring on the set pin tied to the output. This is mentioned in http://cds.linear.com/docs/en/lt-jou...bertDobkin.pdf

I would probably opt for the LT3081 which uses 50uA "set" current.
  Reply With Quote
Old 4th September 2017, 11:57 PM   #16
tomchr is offline tomchr  Canada
diyAudio Member
 
tomchr's Avatar
 
Join Date: Feb 2009
Location: Calgary
Quote:
Originally Posted by jackinnj View Post
My apologies to Tom in Calgary, this topic has been well rehearsed: http://www.diyaudio.com/forums/tubes...regulator.html
No worries.

Quote:
Originally Posted by DualTriode View Post
Tom in Calgary has gone to the dark side and his series regulator in now commercial. No longer DIY supported.
Not at all. I fully support DIY. I just don't give my circuits away for free like I used to. Turns out you can't run a business if you give away your product for free. Who'd have thought.

As Jack points out I've been using the LT3080 in a Maida-style regulator for years now. It works very well. With low-current zeners you can minimize the input-to-output coupling and get truly stellar line regulation.

Quote:
Originally Posted by jackinnj View Post
I would probably opt for the LT3081 which uses 50uA "set" current.
I haven't found the 10 uA of the LT3080 to be an issue. As long as you're reasonably careful with the layout and clean up the flux after soldering up the board, you'll be fine. It never ceases to amaze me how a little flux in the wrong place will completely blow the performance of a precision DC system.
Obviously with 5x the Iset, you can have 5x the amount of flux contamination.

Tom
__________________
Modulus-86: 40W/8Ω @ 0.000061% THD. HP-1: 3W/20Ω, 450mW/300Ω @ 0.000032% THD. DG300B and Other Tube Circuits.
Neurochrome : : Audio - www.neurochrome.com - Engineering : : Done : : Right

Last edited by tomchr; 5th September 2017 at 12:06 AM.
  Reply With Quote
Old 27th October 2017, 11:29 PM   #17
DualTriode is offline DualTriode  United States
diyAudio Member
 
Join Date: Aug 2009
Location: Sacramento
Default Side by Side by Side

Hello,

To put this into perspective I am making a SET 12B4A headphone amplifier. First the goal is to get the noise floor as quiet as possible for as few dollars as possible. The next step is to tune the 12B4A SET to minimize the FFT harmonic profile. That leads to optimizing the signal to noise Raito at the equivalent output of 90dB into Audeze LCD-2 headphones. (About 1 v RMS into 70ohms)

I have assembled the three different regulators; one of Pete’s, one of Tom’s and a Salas style HV Shunt from K&K Audio.

I will test these with the AP 2522 on the bench.

DT
Attached Images
File Type: jpg 20171027_151722.jpg (1.06 MB, 246 views)

Last edited by DualTriode; 27th October 2017 at 11:33 PM.
  Reply With Quote
Old 4th December 2017, 05:01 PM   #18
bandol83 is offline bandol83  France
diyAudio Member
 
Join Date: Nov 2004
Location: near Bandol, French Riviera
Hello DT,

Have you some feedback about your comparison of power supply ?

I have also made two different style of power supply for my RIAA preampli ( Merlin RIAA Preamp ), the first one is a simple version stabilized with three 100 V Zener diodes and the second one use a LT3080 in a Maida like regulator... I wanted to be able to use it also as a high voltage variable lab power supply (50 - 350 V). The un-populated part of the second PCB is just a 6.3 V 5 A regulated power supply for heaters, like in the first version (it is too much for the preampli, but the power supply can also be used with a power amplifier).

It is quite different than the ones you are testing since I wanted to have on the same PCB both the high voltage and the 6.3 V heater power supply and their rectifier with the 100 uF 400 V and the 10'000 uF 25 V capacitors, therefor it can be directly connected to my toroďdal transformer as you can see on the third photo (the heater should be 6.3 V, I have to replace a 470 ohms resistor by a 487 ohms, i didn't have them in stock when I have build the board)...

The connector indicated "SELF" can be used in the filter area of the power supply to connect a resistor (C-R-C) or a choke like in the last photo (C-L-C) or even a NTC to reduce power on surge current, but it can also be simply ignored and connected with a wire !

The first power supply is working very well and is currently powering my RIAA preampli

I have started the test with the second one, but I have the following problem : with the input voltage of 250 V AC (about 350 V DC) I can only adjust the output voltage from 47 V (this is OK for the fixed resistor) to 177 V I am using a fixed 47k resistor and a 470 pot that I can use only on one third of total course !

May be the circuit don't like the 10 inches connection to the pot ?

Marc
Attached Images
File Type: jpg alim RIAA.JPG (309.9 KB, 167 views)
File Type: jpg Alimentation HT gros plan.jpg (303.6 KB, 158 views)
File Type: jpg test alim.JPG (558.6 KB, 160 views)
File Type: jpg alim avec self 10 H.JPG (349.7 KB, 158 views)
  Reply With Quote
Old 4th December 2017, 10:36 PM   #19
Merlinb is offline Merlinb  United Kingdom
diyAudio Member
 
Merlinb's Avatar
 
Join Date: May 2006
Location: Lancashire
Quote:
Originally Posted by bandol83 View Post
I have the following problem : with the input voltage of 250 V AC (about 350 V DC) I can only adjust the output voltage from 47 V (this is OK for the fixed resistor) to 177 V I am using a fixed 47k resistor and a 470 pot that I can use only on one third of total course !
I'm lost. What circuit are you using?
  Reply With Quote
Old 5th December 2017, 10:59 AM   #20
bandol83 is offline bandol83  France
diyAudio Member
 
Join Date: Nov 2004
Location: near Bandol, French Riviera
Hello Merlin,

Below is the schematic of this power supply.

It is a second version after the one with three 100 V Zener, very similar to the 300 V power supply described in your book Fig. 11.46 but with a current source for the Zener and no current limit. It was shown in the RIAA thread : Merlin RIAA Preamp and as you comment it, this power supply is working very well with the RIAA preampli

This second power supply is closer to the Maida regulator in your book Fig. 11.48, but with a LT3080 regulator which offer an improvement of 20 dB PSRR over the venerable LM317. It has been used by several people on this forum (like Tom) with very good results : 21st Century Maida Regulator I am using an IRFI840G for the MOSFET, it is not very powerful (only 43 W...), but I made a mistake on the layout using a MOSFET TO220 pattern instead os a TO247 It is enough for the preliminary test but later I will adapt a more powerful transistor...

Cheers,
Marc
Attached Files
File Type: pdf Schema Power supply variable IRFI840.pdf (114.5 KB, 56 views)
  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 03:04 PM
High Voltage Regulator mod_evil Power Supplies 36 28th October 2011 01:48 PM
high voltage regulator wleediy Solid State 2 4th August 2009 08:12 AM
High voltage, high current super regulator, possible group buy peranders Group Buys 54 2nd June 2009 10:43 AM


New To Site? Need Help?

All times are GMT. The time now is 10:21 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki