LM317 current regulator - Page 2 - diyAudio
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 17th January 2003, 12:32 PM   #11
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Hi Bas,

Use Duncan's PSU program to simulate.
It'll depend on your smoothing to a great extent.

I use DC for the drivers through CRC smoothing, with a resistor in the top and bottom rails. This gets rid of the slow common mode crap. The fast stuff is trapped by a common mode choke.

The 845's use AC at present, and the hum is only just good enough. I'm considering DC.
I considered HF heating, but decided against it because of possible IMD.

Cheers,
  Reply With Quote
Old 17th January 2003, 03:19 PM   #12
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default WHY WORRY?

Hi Bas,

Why would you want to do this?

Do your DHT flash up at switch on?

Cheers,
__________________
Frank
  Reply With Quote
Old 17th January 2003, 03:30 PM   #13
Joel is offline Joel  United States
diyAudio Member
 
Joel's Avatar
 
Join Date: Oct 2002
Location: Brooklyn, NY
I agree with Frank, Bas. What possible benefit is there to current limiting filaments?
I'm building a voltage regulated supply for my DHT filaments this weekend, but it's for lowering hum mostly - as far as how much current they draw - who cares?
  Reply With Quote
Old 17th January 2003, 03:34 PM   #14
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default CURRENT.

Hi,

Quote:
as far as how much current they draw - who cares?
Well,you should care of course.
But as long as the PSU can supply the current they require I don't see any advantage.
Just don't starve them on current.

All current (no pun) tubes have controlled heater warm up built right in anyway.

Cheers,
__________________
Frank
  Reply With Quote
Old 17th January 2003, 03:52 PM   #15
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Why am I doing this...well...because....i can!!

Just kidding.

Know the old discussion about AC/DC on the filaments? Sure you do.

Apparently one of the better sounding DC solutions is current regulation. (Jeez where have you guys been the last couple of years) ;-)

Doede Douma of www.dddac.de fame has made a couple of boards..so he must be thinking of doing the same thing. He has these boards where you have voltage reg and current reg.
(Actually just checked a new page (for the first time) of his out where he says a couple of things about it and actually has the formula that I originally posted for) Duh..RTFM BAS

I want to go a step further and do some filtering after that... as John is doing...ie resistors for the slow junk and common mode chokes for the fast nasties.

Thereby creating a sort of deluxe DC filament supply hopefully able to compete with AC.

What do you guys think...Personally I am baffled by the fact that most people agree AC on filaments sounds better...and the EE type DIY'ers have not designed some ultra good sounding DC supply, with boards and the works. There must be a good market for that.

Cheers,
Bas
  Reply With Quote
Old 17th January 2003, 04:09 PM   #16
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Baz,

My gut instict is that regulation (of either type) is only useful for controlling emission. And that the variations in my mains supply: about 0 to -3%, do not warrant it.
Indeed, if I were to incorporate regulation, I would need to include further noise filtering, as regualtors can be "noisy buggers".

Regarding current vs. voltage regulation:
Most of the valves we use are specified for either:
1) Fixed voltage source
or,
2) Fixed current source
The fixed current source types are mainly TV and AC/DC radio types.
I am unconvinced that running a valve contary to it's specification will reap benefits.

So there..

The few "dual specified" types that come to mind are the ECC8X series, but even they have different pins used for each.

Cheers,
Having just read this through, it sounds really bitchy; it's not meant that way.
  Reply With Quote
Old 17th January 2003, 04:13 PM   #17
Joel is offline Joel  United States
diyAudio Member
 
Joel's Avatar
 
Join Date: Oct 2002
Location: Brooklyn, NY
Quote:
Originally posted by Bas Horneman
What do you guys think...Personally I am baffled by the fact that most people agree AC on filaments sounds better...
This is merely fashionable at the moment. In 5 years everybody and his brother will swear by DC.
What I'm baffled by is just how many people assume everybody in 1930 was retarded.
  Reply With Quote
Old 17th January 2003, 04:15 PM   #18
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
You bitch you! I'll bitch slap you right off this forum. ;-)

Ok enough joking..

Hi John,

John being in EE I can see why you would say that..
Quote:
My gut instict is that regulation (of either type) is only useful for controlling emission
My standard response is if it sounds good it is good...!!!
  Reply With Quote
Old 17th January 2003, 04:22 PM   #19
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Bas,
Quote:
Why am I doing this...well...because....i can!!
If dogs could talk..

Cheers,
  Reply With Quote
Old 17th January 2003, 05:04 PM   #20
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
It's a dog eats dog world..
  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
TIP50 + LM317 High Voltage Regulator bee696 Tubes / Valves 11 17th January 2010 04:23 PM
LM317 Regulator Problem Bryan Tubes / Valves 12 2nd December 2005 07:37 PM
current boost lm317 prob. deepanger Solid State 15 7th October 2004 06:52 AM
Can LM317 be used as GC PS regulator? goering Chip Amps 5 15th September 2004 08:39 PM
current boosted lm317.. deepanger Solid State 6 11th September 2003 01:30 PM


New To Site? Need Help?

All times are GMT. The time now is 02:11 PM.


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