F5 power amplifier - Page 1220 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 12th April 2012, 04:46 PM   #12191
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
check mounting of outputs

torque , goo
__________________
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 12th April 2012, 04:59 PM   #12192
Rush is offline Rush  United States
diyAudio Member
 
Join Date: Sep 2009
Location: Tampa, Florida
Quote:
Originally Posted by uvellani View Post
I am having a problem on one of the channels. This was working fine for over a year when all of a sudden one channel developed this problem. I changed the adjustment pots based on suggestion from this forum, and it worked for a few days of extended testing and listening. But now it's doing it again. The bias voltage on the output resistors dropped from .575 to about .400 at first but now it is all over the place. The other channel is rock-steady.

Do you think the thermistors themselves could be a problem? I know, I know. I could change them and see. But unfortunately, due to the beauty of my chassis layout, I have to take out the power supply and the big caps out first to get at the amp board. So iterative troubleshooting is a bit of a pain. Some pointers would be helpful.

Thanks
UV
Could it be a slow oscillation?

Rush
  Reply With Quote
Old 12th April 2012, 05:46 PM   #12193
diyAudio Member
 
bobodioulasso's Avatar
 
Join Date: May 2008
Bah, next chassis vill be more serviceable i presume.
  Reply With Quote
Old 16th April 2012, 03:16 AM   #12194
diyAudio Member
 
Join Date: Feb 2012
Location: Stad Gemeente Batavia
i have a good quality of toroidal transformer with 2x36vac 500va
and i want to use them in my F5
questions:
1. is that possible to regulating the 2x36vac into 2x18vac without loosing the current? anyone have the schematics for this?
2. if regulating is possible, should it placed before the filter caps (the 15000uf), or after?

thanks.
  Reply With Quote
Old 16th April 2012, 03:24 AM   #12195
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
Quote:
Originally Posted by wengtech View Post
i have a good quality of toroidal transformer with 2x36vac 500va
and i want to use them in my F5
questions:
1. is that possible to regulating the 2x36vac into 2x18vac without loosing the current? anyone have the schematics for this?
2. if regulating is possible, should it placed before the filter caps (the 15000uf), or after?

thanks.
How many primary windings are there? What country do you live in?
  Reply With Quote
Old 16th April 2012, 03:47 AM   #12196
diyAudio Member
 
Join Date: Feb 2012
Location: Stad Gemeente Batavia
primary 0-220-250
secondary 0-36-55 0-36-55
addition 18-0-18

shown on my toroidal transformer.
  Reply With Quote
Old 16th April 2012, 03:55 AM   #12197
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
I was hoping you lived in USA. Looks like that isn't the case. Regulating the rails for an amplifier is a project in itself. I would say you're better off buying the correct transformer and putting that one aside for another project.
  Reply With Quote
Old 16th April 2012, 04:08 AM   #12198
diyAudio Member
 
Join Date: Feb 2012
Location: Stad Gemeente Batavia
i am in indonesia.
i just hoping not to be redundant.
if i saw at the F5 manual, said the regulated supply like zen variation #3 or #5 are good to applied on F5.

and i found on googling this kind of circuit:
Click the image to open in full size.

but don't know yet is that a good schematic or not.
  Reply With Quote
Old 16th April 2012, 08:48 AM   #12199
Floric is offline Floric  Europe
diyAudio Member
 
Join Date: Jan 2005
Location: Bavaria
Hi,

I don't know that schematic, could work. But you would need adequate heatsinks for it. In fact you need twice the heatsinking capability than the original amp for your amp+ps.

At least here in europe the main factors for the costs on an amp like this are the heatsinks and the transformer. I think you will get a cheaper and better amp if you buy an adequate transformer.

Best regards

Flo
  Reply With Quote
Old 16th April 2012, 10:26 AM   #12200
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
One cannot easily regulate AC voltage.
We generally adopt converting the AC to DC and regulate to the required voltage.

Starting a project with the wrong transformer is silly.

Buy the correct transformer, or select a project that will work properly with the transformer you have.

BTW,
you have 19Vac tappings on your transformer, but the VA available is ~18% of the total. i.e. 90VA from each of the two 19Vac windings, (if the wire to the 55Vac taps is the same as the wire in the remainder of the winding).
__________________
regards Andrew T.

Last edited by AndrewT; 16th April 2012 at 10:30 AM.
  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
Rockford Fosgate Power 20001 bd amplifier power rating?? pachoorion Car Audio 8 8th May 2011 11:49 PM
Power transformers versus amplifier output power..what is your option? destroyer X Solid State 38 9th May 2009 06:23 PM
McIntosh Power Amplifier Power Guard johnnyrt Solid State 2 23rd August 2007 11:22 PM
Output power for a power amplifier Progg70 Solid State 33 10th September 2006 09:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality MARAVILLASAUDIO Class D 1 5th November 2004 05:06 PM


New To Site? Need Help?

All times are GMT. The time now is 09:11 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