two rectifiers one transformer? - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 24th January 2005, 04:21 PM   #1
homer09 is offline homer09  Canada
diyAudio Member
 
homer09's Avatar
 
Join Date: Jan 2004
Location: Montreal
Default two rectifiers one transformer?

Hi,

I was just wondering if anyone has built a gainclone using a single transformer which branches out to two rectifier boards. I was looking at BrianGT's gallery of finished gainclones, but no one seems to be doing this.

Is there any advantage of using two rectifiers, or is there really only a difference when you have two transformers? Is this more or less of an issue with a snubberred power supply?
  Reply With Quote
Old 24th January 2005, 04:33 PM   #2
diyAudio Moderator
 
pinkmouse's Avatar
 
Join Date: Apr 2002
Location: Chatham, England
To use two rectifier boards with one traffo, you need to have split secondaries, ( four wires coming out, for instance: 15-0-0-15), not just a centre tap, (three wires: 15-0-15)

Oh, and two rectifiers reduce noise, and enable better rectifiers, (usually lower current handling), to be used if required.
__________________
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
  Reply With Quote
Old 24th January 2005, 04:35 PM   #3
HDTVman is offline HDTVman  United States
diyAudio Member
 
Join Date: Aug 2001
Location: Chicago area
The only advantage to using 2 rectifiers (bridge type I assume) is to provide seperate filtering for each channel of a 2 channel amp. This can result in better crosstalk performance and somewhat better PS regulation than a single rectifier/filter type of power supply. This results from each channel having it's own filter caps.

The only down side is that the extra caps and rectifiers will take up room in the chassis.

I'd say go for it.

BZ

By the way you can do this. just parallel the bridges with the output going to each set of caps.
__________________
What ever makes the tunes flow
  Reply With Quote
Old 24th January 2005, 04:51 PM   #4
homer09 is offline homer09  Canada
diyAudio Member
 
homer09's Avatar
 
Join Date: Jan 2004
Location: Montreal
Quote:
Originally posted by HDTVman

The only down side is that the extra caps and rectifiers will take up room in the chassis.
I see another disadvantage...cost

Thanks for the quick replies guys.

Yes pinkmouse, i was planning on using a dual secondary transformer, thanks for the confirmation.

Im going to be using the BrianGT boards (more specifically his new snubber board), so i will just split each of the transformer's 4 leads into 2 leads for a total of 8. Then feed 4 leads to each rectifier.

Does that make sense HDTVman?
  Reply With Quote
Old 24th January 2005, 05:04 PM   #5
diyAudio Member
 
Join Date: Jul 2001
Location: The Netherlands
Hi,

I think I did exactly what you describe: one xformer, dual secondary, 2 diode bridges (16 diodes) .. if you do it neat (1 real star ground) it can work just fine.. weird thing was that I didn't like it that much... I thoughd that a single bridge sounded better... so I converted back to 1 bridge, but maybe I folled myself..
  Reply With Quote
Old 24th January 2005, 05:15 PM   #6
homer09 is offline homer09  Canada
diyAudio Member
 
homer09's Avatar
 
Join Date: Jan 2004
Location: Montreal
Quote:
Originally posted by tschrama
Hi,

I think I did exactly what you describe: one xformer, dual secondary, 2 diode bridges (16 diodes) .. if you do it neat (1 real star ground) it can work just fine.. weird thing was that I didn't like it that much... I thoughd that a single bridge sounded better... so I converted back to 1 bridge, but maybe I folled myself..

Thats interesting. Ive also heard people say the same thing about dual transformers. They sound is a better smoother, softer with a single supply.

What differences did you notice? I was considering this for a snubber supply, and since this is a high capacitance supply, i think their will be a much more noticeable difference. Any thoughts?
  Reply With Quote
Old 24th January 2005, 05:33 PM   #7
HDTVman is offline HDTVman  United States
diyAudio Member
 
Join Date: Aug 2001
Location: Chicago area
[
Im going to be using the BrianGT boards (more specifically his new snubber board), so i will just split each of the transformer's 4 leads into 2 leads for a total of 8. Then feed 4 leads to each rectifier.

Does that make sense HDTVman?

Ya, that should be OK. I scratch build so I can make it any way I want and was thinking that way when I answered before.

Good luck

BZ
__________________
What ever makes the tunes flow
  Reply With Quote
Old 24th January 2005, 05:52 PM   #8
Warp Engineer
On Holiday
 
AudioFreak's Avatar
 
Join Date: Oct 2001
Location: Queensland, Australia
Using dual secondaries with 2 bridges also puts less stress on the transformer.
__________________
- Dan
  Reply With Quote
Old 24th January 2005, 06:01 PM   #9
gmarsh is offline gmarsh  Canada
diyAudio Member
 
gmarsh's Avatar
 
Join Date: Apr 2004
Location: Halifax, NS, Canada
Suppse you configure a transformer as center-tapped and rectify it with a single bridge rectifier to two rails, and the voltage on the two sides of the transformer winding isn't matched.

The "higher voltage" winding will handle more current. Depending on power supply load, input capacitor size and how bad the voltage mismatch is, it's entirely possible that the lower voltage winding won't ever conduct any current... Even with a small mismatch, your "full wave" input rectifier can resemble a voltage doubler.

Two bridge rectifiers prevent this from ever happening, since each rail gets its own winding.
  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
Two rectifiers raypalmer Chip Amps 14 22nd December 2008 05:48 AM
Two Rectifiers, One transformer jkeny Tubes / Valves 9 1st August 2008 04:15 PM
Newb question...Center pot'ed transformer and rectifiers Stasiu Power Supplies 10 3rd December 2006 08:11 AM
UCD 400 - Rectifiers kephaudio Class D 1 21st May 2005 07:06 PM
How many rectifiers? Valverine Tubes / Valves 6 15th February 2004 03:00 AM


New To Site? Need Help?

All times are GMT. The time now is 05:20 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