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

Pass Labs This forum is dedicated to Pass Labs discussion.

F5 power amplifier
F5 power amplifier
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 September 2009, 12:39 PM   #4961
udailey is offline udailey  United States
Passive Aggressive
diyAudio Member
 
Join Date: Mar 2008
F5 power amplifier
No, nothing special. Maybe you have dropped voltage over the resistors in your power supply.
Uriah
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 24th September 2009, 12:48 PM   #4962
sekess is offline sekess  United States
diyAudio Member
 
Join Date: Feb 2006
Location: NJ
Default Low Voltage

Hi Samoloko,

I don't know your circumstances. But, I too had slightly low rails on one of my builds -- about 22V or so. It's probably from one of the following:

1. low mains voltage

2. tramsformer's specs and regulation are such that you get lowish secondary voltage

or

3. you're dropping too much voltage across the dropping resistors

Steve
  Reply With Quote
Old 24th September 2009, 12:51 PM   #4963
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
F5 power amplifier
Quote:
Originally Posted by samoloko View Post
has anyone compared bridge block vs MUR30x0
I use bridge block (KBPC3510) at now but got low rails - 21.8Vdc
I wonder how on semi ultrafast and softrecovery devices would perform
Is there something special about bridge mr Pass use In his F amps
with shottky diodes you'll have somewhat higher voltage , but not much .

just compare voltage sag across plain vs. shottky diodes , and you'll know .

Papa uses plain bridges in his F amps ,at least to my knowledge
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 24th September 2009, 02:24 PM   #4964
samoloko is offline samoloko  Bulgaria
diyAudio Member
 
Join Date: Jun 2006
thx for your reply
after transformer I got 18.2 Vac
after block bridge 22.1 Vdc
after resistor 21.8 Vdc
could It be old smoothing caps
  Reply With Quote
Old 24th September 2009, 02:57 PM   #4965
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
F5 power amplifier
a smoothing cap with high ESR will run "hot" -- the energy has to go somewhere.
  Reply With Quote
Old 24th September 2009, 04:54 PM   #4966
jackinnj is offline jackinnj  United States
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
F5 power amplifier
Industrial Strength F5:

Click the image to open in full size.
  Reply With Quote
Old 24th September 2009, 07:54 PM   #4967
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
I live in the Netherlands and there are not so many options for transformers to use in the F5.

RS Components sells some excellent 18 V AC trannies that are shielded and dead quiet. However the maximum they offer for 18 V AC is 225 VA.

http://nl.rs-online.com/web/search/s...duct&R=2238825


I guess that is not really enough for two channels F5.

My intention is to build a stereo amp that uses 2 F5 in parallel per channel, so 4 F5 amps for a stereo amp. I also use the CViller PSU boards.

My question to the more experienced:

Can I use two of these 225 VA trannies to feed one PSU board that will feed 2 F5 amp boards, without running into trouble with hum or sound degradation? (Of course I would be forced to use the outputs of the trannies in parallel and use one for the positive rail and one for the negative rail).

Or is it neccesary to use two PSU boards for one channel? That would make 4 PSU boards for the stereo amp, and since I want to use chokes (CLC instead of CRC) that would require 8 chokes, which calls for a lot of space and money!
Or is this the preferred route?

Please can some expert give me advice?

Thanks!


Lucas
  Reply With Quote
Old 24th September 2009, 08:59 PM   #4968
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
F5 power amplifier
Quote:
Originally Posted by jackinnj View Post
Industrial Strength F5:
Nice chassis. Did you make it yourself?

  Reply With Quote
Old 24th September 2009, 09:02 PM   #4969
Melon Head is offline Melon Head  Australia
Banned
 
Join Date: Nov 2006
RS components are usually quite expensive when it comes to transformers. I would try seaching for a local manufacturer, who will make the transformers to your exact requirements. In Australia we have Harbuch http://www.harbuch.com.au/toroids1.htm , he builds an absolute quality product to whatever requirements you would like. I am not neccessarily suggesting you should buy from him, but maybe have a look around locally for someone like him.
  Reply With Quote
Old 24th September 2009, 09:06 PM   #4970
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Quote:
Originally Posted by thanh1973 View Post
RS components are usually quite expensive when it comes to transformers. I would try seaching for a local manufacturer, who will make the transformers to your exact requirements. In Australia we have Harbuch http://www.harbuch.com.au/toroids1.htm , he builds an absolute quality product to whatever requirements you would like. I am not neccessarily suggesting you should buy from him, but maybe have a look around locally for someone like him.
Try www.farnell.co.uk
__________________
Murton-Pike Systems PCBCAD51 pcb design software. http://www.murtonpikesystems.co.uk
  Reply With Quote

Reply


F5 power amplifierHide 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
Rockford Fosgate Power 20001 bd amplifier power rating?? pachoorion Car Audio 8 8th May 2011 10:49 PM
Power transformers versus amplifier output power..what is your option? destroyer X Solid State 38 9th May 2009 05:23 PM
McIntosh Power Amplifier Power Guard johnnyrt Solid State 2 23rd August 2007 10:22 PM
Output power for a power amplifier Progg70 Solid State 33 10th September 2006 08:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality MARAVILLASAUDIO Class D 1 5th November 2004 04:06 PM


New To Site? Need Help?

All times are GMT. The time now is 06:28 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki